Survival of the Fittest

By Paul Rogers

We all know that exercise and physical activity is good for us: authorities have been belting out the message for decades. Even so, it all gets a little confusing trying to decide how much, what type of exercise, and how to know if you’re doing enough by any measurable parameter.

Now it seems we have some real numbers to work with.

Kodama and colleagues at the Department of Internal Medicine, University of Tsukuba in Japan completed a meta-analysis of cardiorespiratory fitness as a predictor of all-cause mortality and cardiovascular events in healthy men and women. (A meta-analysis combines all relevant studies focusing on a particular outcome and analyses the collective results.) Thirty-three studies were included in the analysis.

Fitness Lowers Heart Attack Risk and Increases Longevity

The results were quite informative, even though these types of observational study cannot provide too much certainty at the detail level. However, we do know that fitness generally has positive, preventive effects on heart disease and some cancer risks, and possibly other longevity factors such as immunity, but this study has given us some practical working numbers in terms of  fitness and performance by age group.

 The researchers classified participants by their measured fitness and aerobic power in terms of METS or metabolic equivalents. A MET is the amount of  energy consumed at rest and 8 METS would be the ability to exercise at 8 times the energy expenditure of sitting still, or the ‘resting metabolic rate’. Participants were categorized as low cardiorespiratory fitness (CRF) (less than 7.9 METs), intermediate CRF (7.9-10.8 METs), or high CRF (greater than or = 10.9 METs).

Here are the results:

1. Compared with participants with high CRF, those with low CRF had a relative risk for all-cause mortality of 1.70; and for CHD/CVD events of 1.56. 
2. Compared with participants with intermediate CRF, those with low CRF had a relative risk for all-cause mortality of 1.40 and for CHD/CVD events of 1.47

Those risk numbers, 1.70 and 1.56, for example, describe the increase in risk comparing those with lower fitness (1.70, 1.56) to those with higher fitness 1.0, 1.0). You can see that as you get fitter, your risks of a heart event (heart attack or stroke or similar) or death decrease rather dramatically. Or, you can look at it the other way around: the less fit you are, the greater your risks of a heart event or death compared to a much fitter person.

What This Means in Practical Terms

 Why this study is so useful is that the authors interpreted the results in language  that is explanatory to non-specialists. For example, the minimum cardiorespiratory fitness level that seems to be protective is 9 METs for men at age 40, 8 METs for men at age 50, and 7 METs for men at age 60. For women, it is 7 METs at age 40, 6 METs at age 50, and 5 METs at age 60.

To translate this into walking or jogging speeds, based on Kodama’s data, the speeds would be (in miles or kilometres per hour):

8 METS — 4 mph or 6.4 kmh (very fast walk)

10 METS – 5 mph or 8.0 kmh (slow jog)

12 METS — 6 mph or 9.6 kmh (jog)

If, at 60, you can do 6 miles or 10 km in an hour (12 METS), then you are in the super fit category, because this would even be highly protective fitness for a 40-year old — according to the data from this study.

This is encouraging for people who are not really into hard-core fitness programs. You do have to be fit to walk at 8 METS for an hour, but not exceptionally so. A regular walking program will likely see you achieve this performance well past age 60. For comparison, an amateur fun runner or marathon runner can run at 15 to 18 METS for an hour, and professional endurance athletes at up to 25 METS. 

Add a few sessions of weight training per week for muscle maintenance — at home will do – to your regular walking or jogging, and you can see that keeping fit needs commitment, but it does not have to be too onerous.

– Satoru Kodama; Kazumi Saito; Shiro Tanaka; at al. Cardiorespiratory Fitness as a Quantitative Predictor of All-Cause Mortality and Cardiovascular Events in Healthy Men and Women: A Meta-analysis JAMA, May 20, 2009; 301: 2024 – 2035.

Acid and Alkaline Foods – What Are They?

By Paul Rogers

We all know that citrus fruits and pineapple are acid foods: right? Coffee and tea are acid forming: right?

Are Antioxidants Finished as Dietary Supplements?

By Paul Rogers

Twenty years ago, antioxidant supplements ruled. The famous, now infamous, supplement combination of vitamins A, C and E, was supposed to be a miracle supplement combo that would fight everything from heart disease to cancer. Famous cardiologists started to take vitamin E — and say so — and the whole ACE thing boosted the reputation and sales of supplements the world over.

Vitamin A and beta-carotene

Then things started to go seriously wrong. In 1996, the Beta-Carotene and Retinol Efficacy Trial (CARET) reported on a test of the combination of 30 mg beta-carotene and 25,000 IU retinyl palmitate (vitamin A) taken daily against placebo in 18314 men and women at high risk of developing lung cancer. The CARET intervention was stopped 21 months early because of clear evidence of no benefit, and substantial evidence of possible harm: there was 28% more lung cancers and 17% more deaths in the group that received the beta carotene and vitamin A. These results were similar to those produced in a trial of beta carotene in smokers in Finland.

Strangely, the trial had been prompted by the observation that increased consumption of carotenes (orange to purple colours) in fruit and vegetables might provide protection against lung cancer. This observation seems to hold to this day for food sources of beta carotene — but not for supplements.

Vitamin E

Well, what about vitamin E then? Surely that has some benefit as a supplement? Probably not; in fact, vitamins E, A and beta-carotene supplements may increase mortality. The latest Cochrane review (Bjelakovic) of ACE supplements said this:

“We found no evidence to support antioxidant supplements for primary or secondary prevention. Vitamin A, beta-carotene, and vitamin E may increase mortality. Future randomised trials could evaluate the potential effects of vitamin C and selenium for primary and secondary prevention. Such trials should be closely monitored for potential harmful effects. Antioxidant supplements need to be considered medicinal products and should undergo sufficient evaluation before marketing.”

(Cochrane reviews provide systematic evaluation of the evidence for various biomedical interventions. See http://www.cochrane.org/)

Vitamin C

Vitamin C supplementation seems not to do serious harm but provides little benefit either for most end points, including cancer, heart disease and immunity. Even the early promise of ACE supplements for the prevention of age-related macular degeneration of the eyes has not been confirmed; and in the light of potential harm from E, A and B-C, this course is not recommended, even though a high dietary intake of whole plant foods may be beneficial.

There may still be health niches where vitamin C supplementation is useful — in smokers with poor dietary intake and in low-dose supplements and multivitamins for example — but the good old days of vitamin C as a miracle vitamin is long gone. High and megadoses >200 milligrams/day may even be limiting for athletes and regular exercisers by interfering with energy systems and oxidative metabolism – but that’s another story.

Selenium

Selenium, not so long ago, was the new kid on the block with promise of prevention of prostate cancer, cancer in general, and heart disease. But now, it seems that the infamous J curve could be at work again. In sufficient amounts, selenium might do all of these things or at least not be toxic, but at higher supplement doses, perhaps even under the upper limit of safety in the recommended dietary intakes (400 mcg/day), selenium might cause type 2 diabetes (Bleys) in long-term consumers. This data has been somewhat of a shock to researchers and will surely be followed up for confirmation.

After early promise, recent trials of selenium supplements have not shown that selenium supplements reduce prostate cancer risk either.

While it’s obviously still important to get the RDI for selenium (15 to 70 mcg/day infants to adults), supplementation with higher doses does not seem wise.

B vitamins – folate

While not strictly an antioxidant, folate supplementation advice for heart disease and cancer prevention reached a crescendo in the 1990s. Another magic bullet it seemed. Folate’s apparent long-term success in preventing neural tube defects in childbirth added to its reputation as an important vitamin in preventive health.

In a new approach, folate supplementation was supposed to reduce blood levels of the protein homocysteine, high levels of which were thought to contribute to heart disease risk. Reduced heart disease risk has not been borne out in supplement trials, and homocysteine as a risk factor in cardiovascular disease has turned out to be something of a dud (apparently more a marker rather than a cause) — and so has supplementary folate as a useful tool in lowering heart disease risk.

Further, folate works to prevent birth defects by protecting cell division and differentiation. But what if certain cells — colon, prostate, breast — are cancerous or pre-cancerous? Could high folate intakes actually promote cancer by protecting the aberrant cell division? This is the question being considered by cancer researchers. It is not proven, but some are cautious. The evidence for protection or causation with folate, especially for colon and breast cancer, seems mixed. High doses of folate can also mask vitamin B12 deficiency.

Summing up

While various trials will continue to test the value of dietary antioxidant supplements in preventive health, the writing is surely on the wall for their demise for many of the traditional uses for which they acquired reputation — cancer and heart disease. This does not mean that diets high in antioxidant status from plant food consumption may also be harmful. I’ve not seen any evidence that that is true, or even defensible, and most evidence suggests the reverse is true and diets high in natural plant foods are protective.

- Omenn GS, Goodman GE, Thornquist MD, et al.  Risk factors for lung cancer and for intervention effects in CARET, the Beta-Carotene and Retinol Efficacy Trial.  J Natl Cancer Inst. 1996 Nov 6;88(21):1550-9.
- Lin J, Cook NR, Albert C et al.  Vitamins C and E and beta carotene supplementation and cancer risk: a randomized controlled trial.  J Natl Cancer Inst. 2009 Jan 7;101(1):14-23.
- Bjelakovic G, Nikolova D, Gluud LL, et al. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD007176.
- Evans JR, Henshaw K. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD000253.
- Sesso HD, Buring JE, Christen WG, et al. Vitamins E and C in the prevention of cardiovascular disease in men: the Physicians’ Health Study II randomized controlled trial. JAMA. 2008 Nov 12;300(18):2123-33.
- Gaziano JM, Glynn RJ, Christen WG, et al. Vitamins E and C in the prevention of prostate and total cancer in men: the Physicians’ Health Study II randomized controlled trial. JAMA. 2009 Jan 7;301(1):52-62.
- Lee IM, Cook NR, Gaziano JM, Gordon D et al. Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women’s Health Study: a randomized controlled trial. JAMA. 2005 Jul 6;294(1):56-65.
- Sauer J, Mason JB, Choi SW et al. Too much folate: a risk factor for cancer and cardiovascular disease? Curr Opin Clin Nutr Metab Care. 2009 Jan;12(1):30-6.
- Bleys J, Navas-Acien A, Guallar E. Selenium and diabetes: more bad news for supplements. Ann Intern Med. 2007 Aug 21;147(4):271-2.
- Marcus J, Sarnak MJ, Menon V et al. Homocysteine lowering and cardiovascular disease risk: lost in translation. Can J Cardiol. 2007 Jul;23(9):707-10.
- Lonn E, Yusuf S, Arnold MJ et al. Heart Outcomes Prevention Evaluation (HOPE) 2 Investigators. Homocysteine lowering with folic acid and B vitamins in vascular disease. N Engl J Med. 2006 Apr 13;354(15):1567-77.

Prevention and Management of Diabetes with Lifestyle Change

By Paul Rogers

Diabetes comes in a few different medical configurations.

Type 1 Diabetes (insulin-dependent diabetes) was once called juvenile diabetes because it appears mostly in childhood or early teens. Insulin, the hormone responsible for storing  glucose (blood sugar) and fats, fails completely and has to be replaced by injected insulin. Without insulin, glucose and fat and derivative products called ketones build up to dangerous levels in the blood. An autoimmune reaction that destroys the insulin-producing cells in the pancreas is thought to be responsible for type 1 diabetes.

Type 2 Diabetes (non-insulin dependent diabetes), is mostly a disease of lifestyle. Obesity and lack of physical activity are the main drivers of type 2 diabetes or insulin-independent diabetes. For most type 2s, some insulin is active, but the mechanism of storage does not work as well as it should. This is called glucose intolerance and  insulin resistance. Glucose and fats again rise in the blood and cause problems. Unless treated, serious health outcomes such as blindness, kidney failure, heart disease, neuropathy and other complications can occur. More or less complete insulin failure or ineffectiveness (secondary failure) can occur in type 2 diabetics, in which case insulin injection is required.

Gestational Diabetes occurs during pregnancy and although potentially serious, usually abates after the birth. It may indicate susceptibility to type 2 diabetes later in life.

LADA or Latent Autoimmune Diabetes of Adulthood is diabetes that does not appear to be lifestyle related but has similar features to type 1 diabetes including failure of insulin production.

Pre-Diabetes is a condition in which blood glucose (sugar) is high, but not high enough for a diagnosis of type 2 diabetes. It may be reversed with weight loss and exercise.

Diabetes Insipidus is a rare form and not really related to types 1 and 2. It is usually a consequence of failure of a pituitary hormone called antidiuretic hormone. Symptoms are excessive thirst and urination. Specific treatments are available for this form of diabetes.

Lifestyle, Diet and Exercise for Type 1 Diabetes

I’ve described the different types of diabetes because the two main types — type 1 and type 2 – can be different in nature and different lifestyle approaches may be required.

In type 1 diabetes and LADA in the end stage, you have no insulin and you need to inject insulin. Type 1s learn from an early age how to manage their condition and to make sure they don’t have an insulin reaction that causes hypoglycemia (low blood glucose or ‘hypo’), or hyperglycemia (high blood sugar), both of which can cause serious adverse events including fainting and unconsciousness – and death if not treated. Type 1s always carry some form of glucose in candy or lollies or sweet drinks to address hypos. Injectable insulin also needs to be close by.

While physical activity is important for type 1s, they do have to ensure their insulin dose is adjusted accordingly because exercise may increase blood sugar (glucose) use, disposal and storage and the insulin dose may have to be adjusted to avoid hypos (low blood sugar).

For exercise instructors, it’s important to ensure the type 1 person (or type 2 on insulin) has received advice from their doctor or diabetes educator prior to any additional or more intense physical activity they are about to take on. Physical activity in type 1 diabetes is important for all the reasons that exercise is generally beneficial — heart disease protection, weight management, cancer prevention and possibly improvements in glucose disposal and HbA1c, a measure of blood glucose over time. In the past, high-intensity exercise has been regarded as potentially hazardous for type 1 diabetics, but this is no longer valid if the precautions mentioned above are observed. Some of the best athletes in the world are type 1  diabetics, including footballers, swimmers, skiers and basketballers. The exercise program described below for type 2 diabetics is suitable for type 1s.

Type 1s must learn about adjusting their eating and exercise habits to manage blood glucose and insulin. Other than that, no special dietary habits are required other than following a healthy, high-fibre dietary pattern and managing weight. Very low-carb diets are not necessary although some restriction of carbohydrates may work for some people struggling with general blood glucose control. See more about low-carb diets below. Carbohydrate counting and exchanges may be used to stabilise blood sugar.

Lifestyle, Diet and Exercise for Type 2 Diabetes

The first thing to make very clear is that for people with pre-diabetes or a diagnosis of type 2 diabetes, weight loss and increased physical activity is the number one priority after blood glucose is stabilised. Everything else is fiddling around the edges. Fixing these two lifestyle factors has been shown in trial after trial to help reverse pre-diabetes and to improve glucose control in type 2 diabetics as well as reduce HbA1C, the glycated hemoglobin that does damage to arteries and blood vessels, large and small.

Exercise programs

Diabetics are mostly not in good physical shape. Before starting an exercise program, a doctor’s approval is a good idea, if not mandatory. Special considerations may be required for type 2s with certain medical conditions. These may need to be addressed before an exercise program is commenced. If on insulin and glucose-lowering medications, adjustment of the doses may be required with the introduction of an exercise program.  Doctors and diabetes specialist advisors should be consulted.

Uncontrolled blood glucose levels — high or low

Uncontrolled high blood pressure

Unstable heart conditions

Retinopathy (eyes and sight)

Peripheral neuropathy (nerve damage to extremities, foot ulcers etc)

Autonomic neuropathy (nerve damage to internal organs)

Microalbuminuria and nephropathy (poor kidney function)

With approval, a program within the general parameters of the following is suitable. I understand that this commitment won’t suit everyone. Even so,  a structured program of general movement and activity, walking for example, on most days of the week for 30 to 45 minutes is a good basis for more advanced exercise involvement.

Day 1. Aerobic exercise. Walk or jog on a treadmill or outdoors for 30 minutes at moderate intensity. Moderate intensity means in the range 50% to 70% of your maximum heart rate or at a pace at which you can still talk easily enough or recite a poem for example. Swimming and cycling are fine for aerobic conditioning, but you don’t get the advantage of bone building that you do with impact exercise. Standard aerobics, step and pump group aerobics classes are excellent.

Day 2. Weight training. Use this Basic Strength and Muscle program as a guide. You can do this at a gym or you can do most of the exercises at home with a home gym or even a set of dumbbells. The individual exercises are not that critical, but you need to work all of the major muscle groups including the upper and lower legs, arms, shoulders, back, chest, abdominals and buttocks. The reason for this is that the more muscle you exercise and build, the more depots for glucose disposal and storage you create.

Do 8 to 10 exercises including 3 sets of 8 to 12 repetitions in each set. Adjust the load so that you can get through a complete set and so that the final repetition, say number 10, is getting a little harder to do. At the end of the third set of any exercise you should be working somewhat hard but not busting your gut. Rest for two to five minutes before the next exercise.

When starting out, it is important not to overdo things. Do fewer sets or repetitions and use less weight if you need to, but do all exercises and progress to higher volumes and intensity. However, strength and muscle training needs to stress the muscles appropriately. Lifting light dumbbells for 20 repetitions, although not useless, is not what’s required here. Take it easy, but not too easy!

Day 3. Aerobic training as for day 1.

Day 4. Aerobic training as for day 1.

Day 5. Weight training as for day 2.

Day 6. Aerobic training as for day 1.

Day 7. Rest.

With increasing fitness, you can gradually increase the intensity and volume of your exercise program. Employing a qualified trainer with experience in training diabetics is recommended but not strictly necessary if you take it gradually and consult often with your doctor on wellness issues. This program is suitable for type 1 diabetics as well, notwithstanding advice regarding insulin adjustment.

Nutrition and Diet

The current dietary recommendations and guidelines for type 2 diabetes and pre-diabetes from the American Diabetes Association is available. The general composition of diets recommended for type 2 diabetes is not too different from healthy eating recommendations overall. They should be low in saturated fat and trans fat, high in fibre and low in glycemic index (GI). A diet constructed in this way is like to provide good glycemic (glucose) control, heart healthy eating and meet the recommended dietary intakes. Regular exercise will enhance the results. Carbohydrate counting and exchanges may be used to stabilise blood sugar if required.

Are low-carbohydrate diets useful?

Low-carb enthusiasts are keen to recommend low carb and even ketogenic diets for diabetes, both types 1 and 2. For the most part, I don’t agree that this is useful, although moderately low carbohydrate diets, say >40% carbohydrate might be beneficial for some people in some circumstances.

However, it’s not just about total carbohydrates or glycemic load. In at least two randomised controlled trials,  (Wolever) and (Davis), HbA1C (glycated hemoglobin) was not lowered by low-carbohydrate diets after one year compared to high-carbohydrate diets.

In addition, in a low-GI vegan diet for treatment of type 2 diabetes (Barnard), beta cell function (insulin production) was superior with the low-GI vegan diet compared to a low-carb diet after 12 months. This is what the authors said:

“These results suggest that, in patients with type 2 diabetes on diet alone, a Low-GI diet for 1 year increases disposition index, an index of beta cell function, compared with a Low-CHO diet.”

It’s important to note that vegan diets are usually in excess of 70% carbohydrate. The lesson again is that it’s not the quantity, but the quality of carbohydrate that is most important. In this study, the carbohydrate was low-glycemic index and high fibre — whole grains, beans, pulses, fruits, vegetables. I’m not suggesting diabetics need to become vegans, but it is worth noting that glycemic control was improved on a very-high carbohydrate diet.

Low-carb diets also tend to result in a failure to meet recommended dietary intakes (RDI), the lower the diet is in carbohydrates. This may be avoided with very careful food selection, but as a public health recommendation, low-carb is going to fail most people in this respect, and you would need to have substantial nutrition knowledge to be sure all nutrients are covered. You can see a real analysis of a low-carb dietary regimen in this study by Jenny Shaw. Low-carb diets can be low in fibre, folate, calcium, magnesium and some fat-soluble vitamins.

In addition, low-carb diets do not offer any weight loss advantages after 12 months compared to high-carbohydrate diets. This has been shown in sufficient randomised trials for the issue to be settled.

Further, low-carb dieting has to mean high-protein and high-fat dieting. With many type 2 diabetics having chronic kidney disease,  and being overweight, high-protein diets are likely to be a risky recommendation for any health professional advising such people – unless their personal liability insurance is in good shape!

One more thing about low-carb diets. Undiagnosed type 2 diabetics with extremely poor glucose control may be on the verge of ketoacidosis, which is a condition of metabolic acidosis when insulin production has just about ceased, blood glucose is high, and ketone bodies are produced in the body in excess. This is a dangerous condition and can be fatal. A low-carb, ketogenic diet could possibly aggravate such a condition by accelerating ketosis and thus ketoacidosis. Several case reports have already described the possibility of this occurrence (Shah, Chalasani).

Summing up

Finally, diet and exercise choices are important over the long term. A high-fibre, low-GI, diet is likely to be the best choice, as reflected in the recommendations of many countries. Carbohydrate percentages are a moot point, but not a precise one, and moderately low-carb diets (>40%) may help some people with glucose control problems. Even so, the best options to replace carbohydrate in such instances are likely to be vegetable proteins and oils, or perhaps dairy protein — with no increases in red or processed meat consumption.

In conclusion, the best advice for which there is an ample evidence base for lifestyle modification, for type 2 diabetics and pre-diabetics (and type 1s for that matter), is to attain normal weight if possible, eat according to healthy eating guidelines with emphasis on high-fibre/low glycemic index foods, and to exercise most days of the week.

- Thomas DE, Elliott EJ, Naughton GA. Exercise for type 2 diabetes mellitus. Cochrane Database Syst Rev. 2006 Jul 19;3:CD002968. Review.
- Davis NJ, Tomuta N, Schechter C, Isasi CR, Segal-Isaacson CJ, Stein D, Zonszein J, Wylie-Rosett J. Comparative Study of a One Year Dietary Intervention of a Low-Carbohydrate to a Low-Fat Diet on Weight and Glycemic Control in Type 2 Diabetes. Diabetes Care. 2009 Apr 14. Am J Clin Nutr. 2009 May;89(5):1588S-1596S.
- Barnard ND, Cohen J, Jenkins DJ, Turner-McGrievy G, Gloede L, Green A, Ferdowsian H. A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2  diabetes: a randomized, controlled, 74-wk clinical trial. Diabetologia. 2008 Sep;51(9):1607-15.
- Wolever TM, Mehling C, Chiasson JL, Josse RG, Leiter LA, Maheux P, Rabasa-Lhoret  R, Rodger NW, Ryan EA.Low glycaemic index diet and disposition index in type 2 diabetes (the Canadian trial of carbohydrates in diabetes): a randomised controlled trial. Am J Clin Nutr. 2008 Jan;87(1):114-25.
- Wolever TM, Gibbs AL, Mehling C, Chiasson JL, Connelly PW, Josse RG, Leiter LA, Maheux P, Rabasa-Lhoret R, Rodger NW, Ryan EA.The Canadian Trial of Carbohydrates in Diabetes (CCD), a 1-y controlled trial of  low-glycemic-index dietary carbohydrate in type 2 diabetes: no effect on glycated hemoglobin but reduction in C-reactive protein. Am J Clin Nutr. 2008 Jan;87(1):114-25.
- Meckling, K.A. O’Sullivan, C., Saari, D. Comparison of a low-fat diet to a low-carbohydrate diet on weight loss, body composition, and risk factors for diabetes and cardiovascular disease in free-living, overweight men and women. The Journal of Clinical Endocrinology and Metabolism. 2004; 89 (6): 2717-272
- Shah P, Isley WL. N Engl J Med. 2006 Jan 5;354(1):97-8. Ketoacidosis during a low-carbohydrate diet.

Red Meat and Chronic Disease

By Paul Rogers

Red meat is a dietary staple in developed nations of the west — North America, Europe, Australia and much of South America in the more affluent countries and regions. In fact, eating read meat is almost a badge of affluence. In Asia, red meat is not usually the protein of choice, or availability,  although consumption is rising in countries like Japan and China.

Red meat is defined as beef, pork, lamb, veal and goat in foods like hamburgers, minced beef, pork chops and roast lamb.

Lifestyle diseases, nutrition and red meat

The problem is, individuals with the greatest consumption of red meat – and processed meats like ham, bacon, salami and hot dogs – keep showing up in health studies as having a higher incidence of chronic diseases like cancer, heart disease, diabetes and macular eye degeneration. It seems that consumers of the highest quantities of red meat are more susceptible to these diseases than those who eat the  lowest amounts. And, what makes the data more believable, is that in many studies the same risks do not show up for white meats like chicken, fish and turkey. So what’s going on with red meat?

Most of these investigations are prospective type observational studies where groups of individuals are followed forward in time while their disease outcomes are noted along with their diets. The link between red meat and such diseases cannot really be called “causal” because observational studies like these are not rigorous enough to provide that answer conclusively. Even so, when the same results are found in more than one study, the results become more convincing.

Here are some diseases linked to red meat and processed meat consumption, although not all conclusively.

• Cancer – bowel (colorectal) and perhaps breast and prostate
• Type 2 diabetes
• Cardiovascular disease
• Macular eye degeneration

An example of how reducing red meat consumption can improve health is demonstrated by a study in which reducing the amount of red meat in the diet improved kidney function substantially in type  2 diabetics as measured by the urinary albumin excretion rate. (de Mello et al.)

 Is it red meat or fewer plant foods?

If these correlations do turn out to be causal, then what is the mechanism of such an effect? There are several candidates.

• Too much red meat in the diet may result in too few plant foods being ingested and a deficiency of antioxidants, vitamins and minerals that protect against free radicals and other toxic principles. Considering that white meat consumption does not seem to be related to the disease states associated with red meat, this is a questionable scenario.
• Heme iron in excess may be toxic. Strange as it may seem, too much iron from red meats may actually cause an excess of free radicals, mutagenic compounds and consequent damage to  all sorts of tissues. Apparently this does not seem to be the case with non-heme iron, as in plant sources of iron. There’s more to come on that I’m sure, but it is a favoured causal hypothesis.
• Burnt meat can contain known carcinogens like polycyclic aromatic hydrocarbons and heterocyclic amines, which might account for colon cancer and other possible cancers.
• Red  meat as a product of factory farming, feed lots, and various commercial production methods may be contaminated with polychlorinated aromatics like dioxins and PCBs, which are known carcinogens and diabetogens. Free-range and organic production may produce different nutritional profiles.

What you can do to lower the risk

The World Cancer Research Fund recommends limiting consumption of red meat (such as beef, pork and lamb) and avoiding processed meats. They suggest you eat no more than 500 grams (just over a pound), cooked weight per week of red meats, like beef, pork and lamb, and avoid processed meats such as ham, bacon, salami, hot dogs and some sausages. I’ve seen other sources that recommend half this amount. A medium steak is about 145 grams (about one-third of a pound).

– Norat T, Bingham S, Ferrari P, et al.  Meat, fish, and colorectal cancer risk: the European Prospective Investigation into cancer and nutrition. J Natl Cancer Inst. 2005 Jun 15;97(12):906-16.
– Ascherio A, Willett WC, Rimm EB, Giovannucci EL, Stampfer MJ. Dietary iron intake and risk of coronary disease among men. Circulation. 1994 Mar;89(3):969-74.
– Liese AD, Weis KE, Schulz M, Tooze JA. Food intake patterns associated with incident type 2 diabetes: the Insulin Resistance Atherosclerosis Study. Diabetes Care. 2009 Feb;32(2):263-8.
– Chong EW, Simpson JA, Robman LD, et al. Red meat and chicken consumption and its association with age-related  macular degeneration. Am J Epidemiol. 2009 Apr 1;169(7):867-76.
– de Mello VD, Zelmanovitz T, Perassolo MS, Azevedo MJ, Gross JL. Withdrawal of red meat from the usual diet reduces albuminuria and improves serum fatty acid profile in type 2 diabetes patients with macroalbuminuria. Am J Clin Nutr. 2006 May;83(5):1032-8.

 

 

Best Exercises to Prevent Osteoporosis

By Paul Rogers

Building bone strength and density at a young age and holding on to it as we get older is something everyone should be concerned about. Hip replacements and wrist fractures are painful and debilitating at any age. While adequate nutrition, especially the nutrients calcium and vitamin D are essential in early development and throughout life, physical activity plays a complementary role in the development and maintenance of bone density. But what type of exercise is beneficial and how much?

Impact Exercise Rules

Even though weight training or resistance training has received substantial publicity in recent years, how you load the muscles and tendons, it seems, is more important than any categorical approach to exercise for bone health. Impact training in which a jolt is imparted to the tendon, muscle and bone complex seems to be the most effective. Tendons attach muscle to bones, and when you strike the ground – while running for example — each step imparts a compressive force to the bones through the tendons and muscles of the legs. This  “impact” activity has been shown to be the best type of exercise for developing and maintaining bone density. However, it needs to be tempered with restraint to avoid injury, particularly starting out if you’ve not been active for many years or ever.

The Best and Worst Exercises for Preventing Osteoporosis

Best: running, jogging, volleyball, jumping, soccer, weight training, pump and step aerobics, fast walking.
Worst: cycling, swimming, rowing — or anything that’s not weight bearing, especially with impact. 

A new study from the University of Missouri in Columbia, looked at the comparative bone density in a cross section of long-term runners, cyclists and weight trainers — and although both running and weight training had positive benefits, cycling was worst and running somewhat best of all when adjusted for lean body mass. That impact training is the most effective has been known or at least suspected for some time. For example, a study of male and female volleyball players showed a remarkable increase in bone mineral density at most sites, compared to sedentary controls, of between 6 and 18 percent in women and 27 percent in men. Landing with impact has definite advantages it seems.

It is worth pointing out that running doesn’t do much  for your upper body bones, so a combination of impact exercise and weight training for upper and lower body is likely to be an optimum combination of exercise. Combination workouts like pump and step group aerobics where cardio is combined with impact and resistance exercises seems ideal. In addition, there are individual exercises like weighted lunges, bounce or clap pushups, box jumps and even jump squats that satisfy the definition of “impact” exercise but don’t include running. What you probably don’t’ want to do is participate in the ’superslow’ strength training protocol where weights are moved very slowly. Power type exercises done explosively are more likely to provide that jolt required to stimulate bone production.

A word of warning. Impact exercise can cause injuries, especially if you don’t work up to it. Go easy on the plyometric type of exercising like bounding, jumping and high stepping until you get the muscle, tendon and ligament complex used to the stresses of this type of training. The same goes for running long distances in endurance running training.

How Much Do You Need?

If you follow the general exercise recommendation of exercise most days of the week and weight training at least twice each week, and you incorporate some impact exercise at most sessions, this  should satisfy the requirements for exercise healthy bones — although as we age, hormonal status and the amount of bone placed in the “bone bank” during youth is likely to account for individual differences.

J Strength Cond Res. 2009 Mar;23(2):427-35. Lean body mass and weight-bearing activity in the prediction of bone mineral density in physically active men. Rector RS, Rogers R, Ruebel M, Widzer MO, Hinton PS.
Calbet JA, Díaz Herrera P, Rodríguez LP. High bone mineral density in male elite professional volleyball players. Osteoporos Int. 1999;10(6):468-74.
Alfredson H, Nordström P, Lorentzon R.  Bone mass in female volleyball players: a comparison of total and regional bone mass in female volleyball players and nonactive females. Calcif Tissue Int. 1997 Apr;60(4):338-42.

Increasing HDL Cholesterol is the New Focus

By Paul Rogers

Cholesterol from your diet or that produced internally by the body is carried in the bloodstream bundled into complexes called ‘lipoproteins’, which means fat-proteins, ‘lipo’ meaning fat. There are diffent types of lipoproteins classified by how dense they are, that is, how much protein they include. These include high density (HDL), low density (LDL), intermediate density (IDL) and very low density (VLDL) lipoproteins. In addition, the actual particle size has a bearing on what sort of risk they carry for heart disease. (The big fluffy particles are better to have than the small, heavy ones apparently.) It’s a complex situation inside your metabolic environment.

The importance of HDL

The high-density lipoproteins (HDL) do a valuable job in scavenging excess cholesterol from circulation and returning it to the liver for excretion. For this reason, HDL is often called the ‘good’ cholesterol. However, more recently, HDL has been found to have additional properties such as anti-inflammatory and antioxidant behaviour. More focus is being placed on increasing HDL, especially in cases where LDL (bad cholesterol) lowering has not been sufficiently effective.

Cholesterol is an essential fat-like substance (sterol) important in the production of sex hormones and for maintenance of cell membranes. The body produces some naturally and then regulates its production based on how much cholesterol we consume. If we have too much cholesterol in the bloodstream, particularly the small, heavy low-density lipoprotein cholesterol (LDL), some gets oxidised, deposited in arteries and causes artery disease which may result in a heart attack eventually. However, if you have sufficient HDL to scavenge the excess, your heart disease risk will decline because LDL does not get a chance to build up in arteries.

Excess saturated fat from animal foods, coconut and palm oil in the diet, and the trans fatty acids, disrupt the way cholesterol receptors work so the body does not regulate cholesterol production and processing as well.

Women, before menopause at least, usually have higher HDL than men — women greater than 50+ mmol/L (1.3 mg/dL) and men greater than 40+ mmol/L (1.05 mg/dL). Below these numbers is entering higher risk territory for coronary artery disease for either sex.

By raising HDL and lowering LDL or at least not raising LDL at the same time, heart disease risk can be reduced. A ratio of total cholesterol to HDL cholesterol of 3.5 is said to be protective, as is a HDL level above 60 mmol/L (1.55 mg/dL). It depends on your other risk factors: family history, blood pressure, blood glucose, hypertension, obesity, inflammation and so on, but total cholesterol below 4.0 mmol/L (155 mg/dL) is considered to infer very low risk for cardiovascular disease if maintained in good health over an extended period.

How to raise HDL with Lifestyle

HDL seems to be affected by the following nutrition and physical activity principles, so it’s worth trying to raise HDL while reducing LDL at the same time. This is not easy because it is somewhat contradictory.

Increases HDL
– Regular physical activity, probably at moderate to high intensities and duration
– Low-GI and/or high-fibre diets
– Mono- and polyunsaturated fats when they replace refined carbohydrates and trans fats
– Reduced waistline and body fat; slimmer equals better
– A decrease in blood triglycerides often increases HDL
– Red wine and perhaps other alcoholic drinks ( not in excess, 1-2 glasses/day)
– Stop smoking

Decreases HDL
– Smoking
– Trans fats (in fast foods, commercial foods)
– Anything that raises triglycerides (blood fats), tends to lower HDL (overeating, excess alcohol, refined carbohydrates, sugars, low physical activity)
– Alcohol in excess
– Refined, high-GI carbohydrates and sugars
– Reduced physical activity
– Increased body fat

You can probably see from the above, that just following a very low-fat diet won’t necessarily do it, even if it helps reduce LDL cholesterol. You need to make sure you include plenty of fibre and some healthy fats and exclude the highly refined carbohydrates such as biscuits, white bread, cakes, fries and added sugars and excess alcohol. Eating these foods tends to induce the body to constantly use the glucose or alcohol pathways for energy in preference to fat as fuel, thus raising the level of fats (triglycerides), which in turn lowers HDL in liver.

This becomes a vicious circle as insulin sensitivity decreases and glucose tends to stay high in the blood and the triglycerides spike and HDL plummets — and that’s what metabolic syndrome is.

Summary of HDL

Except for people who have a genetic predisposition, low HDL is essentially a disorder of fat and glucose metabolism as a result of too much fat and refined carbohydrate eaten in excess of energy requirements. Under these circumstances, the higher the blood sugar and fat load on your system, the lower the HDL and the higher your blood triglycerides will be.

Lose weight, or at least body fat, eat a high-fibre diet — and with exercise quality, quantity and consistency — most people will see an increase in HDL. A small tipple of red wine may also help. If you exercise consistently at moderate to high intensity and you are of normal weight, you can worry less about portions of high-GI and refined carbohydrates.

For healthy fats, nuts, avocados sunflower seeds and fish oils in whole foods are good choices but be aware of excess energy intake. Choose only modest portions of quickly metabolised carbohydrates such as white bread and pastries and go for heavy wholegrain breads and cereals, fibre-rich beans and plenty of coloured vegetables and whole fruits rather than juices.

Consult your doctor first

Even so, some individuals do not respond to lifestyle interventions to raise HDL. Fortunately drugs such as niacin in special formulations can help, for which you need to consult your doctor. You should also consult your doctor before making any radical changes in diet and exercise, particularly in relation to alcohol consumption and particularly if you are diabetic.

© Paul Rogers

M S Brown, J L Goldstein: How LDL Receptors Influence Cholesterol and Atherosclerosis. Scientific American 1984, 251, pp. 52-60.
Hausenloy DJ, Yellon DM.  Targeting residual cardiovascular risk: raising high-density lipoprotein cholesterol levels. Heart. 2008 Jun;94(6):706-14. Review.
Ma Y, Li Y, Chiriboga DE, Olendzki BC, Hebert JR, Li W, Leung K, Hafner AR, Ockene IS. Association between carbohydrate intake and serum lipids. J Am Coll Nutr. 2006 Apr;25(2):155-63.
Brand-Miller JC. Glycemic index in relation to coronary disease. Asia Pac J Clin Nutr. 2004;13(Suppl):S3.
Ford ES, Liu S. Glycemic index and serum high-density lipoprotein cholesterol concentration among us adults. Arch Intern Med. 2001 Feb 26;161(4):572-6.
Hansen AS, Marckmann P, Dragsted LO, Finne Nielsen IL, Nielsen SE, Gronbaek M. Effect of red wine and red grape extract on blood lipids, haemostatic factors, and other risk factors for cardiovascular disease. Eur J Clin Nutr. 2005 Mar;59(3):449-55.
Williams PT. Relationship of distance run per week to coronary heart disease risk factors in 8283 male runners. The National Runners’ Health Study. Arch Intern Med. 1997 Jan 27;157(2):191-8.
Williams PT. High-density lipoprotein cholesterol and other risk factors for coronary heart disease in female runners. N Engl J Med. 1996 May 16;334(20):1298-303.

Losing Weight and Keeping It Off

By Paul Rogers

Weight Loss and Exercise Guidelines from ACSM

The American College of Sports Medicine (ACSM) has released a new Position Stand, Appropriate Intervention Strategies for Weight Loss and Prevention of Weight Regain for Adults, which addresses obesity and overweight in adults. Specific dietary and exercise recommendations are included. The paper also explores resistance exercise and pharmacotherapy in relation to weight loss and prevention of weight regain.

Here is a summary. Note the recommendation for strength training, which is so important for lean body mass (muscle and bone) maintenance.

Prevent weight gain

• 150-250 minutes/week of moderate-intensity physical activity is associated with prevention of weight gain
• More than 150 minutes/week of moderate-intensity physical activity is associated with modest weight loss.

Lose weight

• 150-250 minutes/week of moderate-intensity physical activity provides only modest weight loss.
• Greater amounts (eg, >250 minutes) provide clinically significant weight loss.
• Energy/diet restriction combined with physical activity will increase weight loss as compared to diet alone.

Maintain weight after weight loss

• There is some evidence that >250 minutes/week of moderate-intensity physical activity will prevent weight re-gain.

ACSM recommends that adults participate in at least 150 minutes/week of moderate-intensity physical activity to prevent significant weight gain and reduce associated chronic disease risk factors. For most adults, this amount of physical activity can be easily achieved in 30 minutes/day, five days a week. Overweight and obese individuals will most likely experience greater weight reduction and prevent weight regain with 250+ minutes/week of moderate-intensity physical activity.

ACSM also recommends strength training as part of this health and fitness regimen, in order to increase fat-free mass and further reduce health risks.

See my advanced weight loss and beginner’s weight loss programs for practical solutions.

The Top 6 Lifestyle Tips to Prevent Heart Disease

By Paul Rogers

If you read about healthy lifestyles, fitness and health regularly, some of these tips may seem like old territory — but wait — you may not know some of the finer details that I’ll share here.

1. Eat Less Animal Fats and Cholesterol and More Unsaturated Fats and Plant Foods

There’s no doubt that diets high in animal fats, saturated fat and cholesterol and trans fats, and low in unsaturated fats and plant foods cause heart disease. But what about plant foods high in saturated fat but no cholesterol? Saturated fats are found in large amounts in palm oil and coconut oil and some of these saturated fats also block cholesterol receptors that help keep cholesterol in the blood under control. However, heart-healthy foods like nuts, olive oil and avocado also have saturated fats in percentages up to around 15%. So what’s the difference?

Apart from the absolute amount of saturated fat in each, here’s the thing: nuts, olives and avocados and their fats also have high amounts of polyunsaturated and, or, monounsaturated fats and fibre, which likely offset or reverse any damaging effects of  their saturated fats. The overall effect is to lower cholesterol. Palm kernel oil contains over 80% saturated fat and coconut oil over 90% saturated fat and are mostly eaten as oils and not as whole foods.

In addition, there is evidence that a synergy exists between consuming saturated fat and dietary cholesterol in a regular diet. The bacon and eggs fried in butter or palm oil is not a good combo.

Regarding animal fats, it should be pointed out that oily fish like sardines have plenty of polyunsaturated omega-3 fats that are strongly recommended in heart disease prevention even though in this context  they are “animal fats.” Also, meats contain some monounsaturated fats and omega-3 fats, especially if grown free-range or grass-fed organic. Naturally lean meats are preferred. The fatty meats are also more likely to contain toxic contaminants like dioxins, PCBs and chlorinated organic pesticides, which are stored in fatty tissue and which some studies show increase cardiovascular risk.

Heart disease risk is further complicated by the fact that some people are cholesterol responders and in these people, blood cholesterol increases in response to cholesterol (and saturated fat) in the diet as a result of genetic susceptibility. And you can’t tell if you’re one of them unless you monitor your diet and cholesterol numbers. In others, regular consumption of cholesterol foods does not raise cholesterol appreciably. However, diabetics seem to be particularly adversely affected by dietary cholesterol — especially egg consumption – and second, if you already have high cholesterol numbers, lowering dietary cholesterol may reduce your blood cholesterol. There’s a difference between steady state consumption and the effect of reducing consumption — even in non-responders.

Overall, that’s why the American Heart Association still recommends low-cholesterol diets of no more than 300 milligrams/day for healthy people and less than 200 milligrams/day for people with existing heart disease or risk, and a saturated fat intake of less than 7%.

2. Consume Less Added Sugar

Sugar is a concentrated form of food energy, so naturally if you’re trying to maintain or lose weight to improve your heart health it’s a good idea to limit your consumption of sugars — cane, beet or corn syrup, or honey for that matter — it’s all “sugar.”

Okay, so sugar can be fattening but at least it’s not saturated fat or cholesterol . . . but wait, are you sure? When you eat too much sugar, especially the fructose part of it, the liver turns fructose into . . . yes, you guessed it, a saturated fat called palmitic acid – one of the worst ones for raising blood cholesterol. Fruit is not going to be a problem because the fructose is in smaller quantities and it has the fibre to slow down it’s digestion and to prevent any conversion to fat. This is called lipogenesis. An apple has about 5 grams of fructose and a can of soft drink about 25 grams. Drink more than a few soft drinks a week and you could be well on the way to the fat farm plus a higher cholesterol reading.

I always like to point out that fit, athletic people who do a lot of hard training have more choice when it comes to consuming added sugars, in fact sugars can be a valuable tool in meeting energy requirements and generally the fructose does not get turned into fat but is converted to valuable glucose for energy.

3. Consume Fewer Refined Carbohydrates Unless You Exercise a Lot

 The story with starches like white bread, white rice and cakes and pastries — apart from the hidden fat and salt in the refined and processed foods — is a little different. Starches end up as glucose, which is not as easily converted to fat because it can be stored in the body in liver and muscle (and fat cells) for future use. Again, athletes and heavy exercisers of normal weight have a little more choice when it comes to refined carbs. The quickly assimilated white bread roll and sports drink at the end of a tough training session could be more help than hindrance.

If you don’t exercise, or if you’re unfit and overweight, starchy  carbohydrates are best eaten with plenty of fibre in whole food form if possible. This will slow down digestion and provide better blood sugar and perhaps appetite control. Use the glycemic index (GI) if you like, but I’m not a big fan of the GI. In my view you’re better off aiming for a high-fibre diet up around the 0.5 grams fibre per kilogram of body weight. That means a lot of plant food in the diet — nuts, beans, seeds, fruit and veges and whole grains.

4. If You Drink Alcohol, Keep It Moderate

It’s not yet clear whether the reasonably certain heart benefits of moderate alcohol consumption are more pronounced with red wine than for other alcoholic drinks. The research data are a little mixed from what I can make of it. Even so, theoretically the red and purple polyphenols in red wine and perhaps grape juice, including resveratrol, may have additional benefits. Overall though, there seems little doubt from the accumulated research that moderate alcohol consumption lowers cardiovascular risk compared with abstinence. That’s in the range to two drinks a day for men and one for women.

It gets a little tricky because alcohol (ethanol) is toxic for the heart and cardiovascular system at higher doses, resulting in increases in blood pressure and even cardiomyopathy at pathologic rates of consumption, along with a wide range of other adverse effects at excessive consumption levels. In addition,  ethanol is also a reasonably strong carcinogen. Breast cancer risk in women increases from about one drink a day and trends upward. Ethanol is a known cause of cancers of the mouth, throat, oesophagus, bowel (colon and rectum), liver and female breast. Alcohol is a potent toxin no doubt, but the dose  makes the poison.

If you don’t drink, it’s difficult for anyone to tell you that you should — including me — and your doctor probably won’t.

5. Do a Combination of Aerobic Exercise and Weights

Aerobic exercise or cardio is a must for building cardiovascular fitness and strength. It builds heart and lung capacity for oxygen processing and also increases capillary blood supply to the muscles and probably even collateral blood supply in the heart muscle to provide support for the coronary arteries plus additional beneficial changes to artery and heart function.

Yet cardio like walking, running or swimming can be a little unbalanced, even though the benefits are undisputed. By adding resistance or strength training you train the whole body and consequently develop regional fitness as well in a way that running or swimming cannot. For example,  by building muscle and maintaining muscle as you age, you provide additional storage sites for glucose disposal. Muscle loss and higher blood glucose readings need not be an inevitable consequence of ageing. High blood glucose levels are a risk factor for diabetes and heart disease. Weight training also improves bones, balance, flexibility and strength. What’s not to like!

6. Don’t Smoke and Maintain Normal Weight

No list would be complete without these two somewhat obvious risk factors. Get there any way you can.

In total, that’s a relatively uncomplicated list. From a lifestyle perspective, you don’t have to attend to much more than these six measures to keep your heart in good nick — except you must get regular checkups because genetics and family history play a large part in your heart disease risk.

A Low-Fat Mediterranean Diet – Is It Possible?

By Paul Rogers

This may seem like a contradiction in terms for anyone who has been used to the propaganda that the traditional dietitians’ low-fat diet and the traditional Mediterranean diet are poles apart. Frankly, it’s bunkum. In fact, the differences between the early Mediterranean diets of Crete and similar regions, and a well-constructed low-fat diet are not much at all.

Here’s what it all boils down to. Take a look at the Oldways diet pyramid and recommendations. The people at Oldways have been studying and promoting Mediterranean diets for 20 years. They note that the Mediterranean diet was not highly specific, but a variable eating pattern within which a range of consistent food consumption and lifestyle behaviours were evident. Here’s what they list:

1. An abundance of food from plant sources, including fruits and vegetables, potatoes, breads and grains, beans, nuts, and seeds.
2. Emphasis on a variety of minimally processed and, wherever possible, seasonally fresh and locally grown foods (which often maximizes the health-promoting micronutrient and antioxidant content of these foods).
3. Olive oil as the principal fat, replacing other fats and oils (including butter and margarine).
4. Total fat ranging from less than 25 percent to over 35 percent of energy, with saturated fat no more than 7 to 8 percent of energy (calories).
5. Daily consumption of low to moderate amounts of cheese and yogurt (low-fat and non-fat versions may be preferable).
6. Weekly consumption of low to moderate amounts of fish and poultry (recent research suggests that fish be somewhat favored over poultry); from zero to four eggs per week (including those used in cooking and baking).
7. Fresh fruit as the typical daily dessert; sweets with a significant amount of sugar (often as honey) and saturated fat consumed not more than a few times per week.
8. Red meat a few times per month (recent research suggests that if red meat is eaten, its consumption should be limited to a maximum of 12 to 16 ounces [340 to 450 grams] per month; where the flavor is acceptable, lean versions may be preferable).
9. Regular physical activity at a level which promotes a healthy weight, fitness and well-being.
10. Moderate consumption of wine, normally with meals; about one to two glasses per day for men and one glass per day for women (from a contemporary public health perspective, wine should be considered optional and avoided when consumption would put the individual or others at risk.)

I don’t necessarily agree with some minor points in this list, but note item number 4. This suggests a range of total fat consumption —  from less than 25% to 35%. The low-fat diets of the American Heart Association (AHA), traditionally regarded as the devil itself by the low-carbohydrate crowd, are in the range 25% to 30% — not much difference.

At number 8, consumption of red meat is very limited — by much more than most people would assume in a Mediterranean diet. So, let’s not pussyfoot around with this: the real Mediterranean diet is quite a restrictive diet for those who are used to eating large amounts of red meat. The idea that you can  splash olive oil on everything, eat some walnuts, drink red wine with the lamb shanks and baklava every night and go to Corfu in 1965 in your dreams is exactly that. Although I would suggest that slightly more red meat in the diet would not necessarily be unhealthy. (Limiting red meat in the diet has received much impetus in recent years from studies showing increased risks of bowel cancer in individuals who eat diets high in red meat.)

Quality Fats, Protein and Carbohydrate Is the Key

The big mistake the AHA and associated nutritionists and dietitians made with early low-fat diet recommendations was that they made little attempt to recommend quality macronutrients — fat, protein and carbohydrates.  Keep saturated fat very low (poly and monounsaturated fats are best); eat a high-fibre diet with nuts and seeds;  concentrate protein on fish, chicken, low-fat dairy, beans and pulses; choose wholegrain cereals and bread; and keep added sugars and refined carbohydrates to a minimum. We’ve known this was a healthy diet for 40 years. They mucked it up. People gorged themselves fat on low-fat cookies, soft drinks and junk food. How stupid was that!

I suspect it’s not the red wine or the olive oil but the abundance of whole, fibrous, natural plant foods and a diet low in animal fats and cholesterol that works in Mediterranean diet studies to reduce heart disease — and probably cancer. Substituting canola oil or even soy or peanut oil for olive oil would probably make little difference. In any case I’d rather keep added oils to a minimum and get healthy fats from whole foods like nuts, seeds, avocados, peanuts and beans.

A low-fat diet of 25% to 30% of mostly good fats within the above eating pattern IS the low-fat Mediterranean diet.

Regular Exercise Rules

Number 9 is a recommendation for regular physical activity. It’s not that the early practitioners of this Mediterranean eating pattern put on their jogging shoes or headed off down to the gym every day to work out. No, they were too busy doing hard manual labour much of the day in the fields and gardens or out on the fishing boats. Try working out how much extra energy you would use working in a job like farming/gardening every day compared to sitting in an office. Don’t worry I’ve done it for you: six hours at walking pace is about 1200 kcalories. Many would have worked much harder and longer than that. What does your regular gym session or run use? Average about 400 to 600 kcalories for 45 minutes.

The thing is, if you work or play hard enough, you can get away with eating and drinking a few refined carbohydrates and sugars. In fact, you may need  them to fuel your work or play. A nice sourdough white bread is a real treat. Honey or even modest amounts of sugar in fruits, juices and desserts is not going to be an issue for those who workout or work hard. Physical activity really is an essential part of any diet pyramid these days. And it should not be an add-on but an integrated component that possibly affects the macronutrient composition of the diet. Try telling a marathoner that he can only eat a 35% carbohydrate diet! Or a hand cane cutter or woodchopper.

The Diet Wars Are Over

Yes, they are, as that article says. Call it Mediterranean, low-fat high-fibre, semi-vegetarian or whatever you like. The principles are pretty much laid out now. All you need  is the will to do it. And the thing is, it’s probably the easiest healthy diet to implement compared to the stringency of low-carb, very low fat and all the other extreme ideas. Go to it.

Steady State v Intervals v Weight Training

By Paul Rogers

If you’ve been reading about fitness and training for a while, you will know that various trainers and fitness experts have a view about which type of exercise is best for health, fitness and body composition — fat loss, muscle building, strength and aerobic and anaerobic  capacity.

The truth is, if you want all round fitness with a lean body, good muscle development and strong endurance, power and speed, you should do all three because they complement each other, even though at some level one will start to dominate the others. Here is a summary of how each type of training affects for your health and fitness.

Steady-state Aerobics

Steady-state aerobics is basically cardio training on the road, track, treadmill, bike etc for anything from 20 minutes to 2 hours. It need not be long slow distance (LSD) as some trainers suggest it is. It does need to be continuous, non-stop activity — allowing for a few tens of seconds or so for refuelling or rehydration. It is valuable in building an aerobic ‘base’ for any fitness activity and for weight loss.

The characteristics of steady-state aerobics are:

• Builds the aerobic system with increased oxygen processing ability (VO2 max)
• Increases mitochondrial  and capillary density in cells, providing increased ability to absorb and use oxygen. (Mitochondria are the energy stations within cells. Capillaries are very small blood vessels. An increase in both enhances aerobic fitness.)
• Builds collateral blood supply to the heart in coronary arteries for increased oxygen supply at times of shortage. (Ischemia from blood clots or exercise demand.)
• Steady-state aerobic exercise uses substantial energy. Sixty minutes of running at 5 minutes a kilometre uses around 950 kcalories.
• Higher  intensity aerobic training, say beyond 75% of max heart rate, also produces some EPOC or ‘excess post-exercise oxygen consumption’. (EPOC ramps up the metabolism after exercise.)
• Unless managed well — especially a nutritional strategy – steady-state aerobics may be catabolic, that is, may reduce muscle mass, bone mass and lead to dysregulation of hormones, especially in women. (This is more likely at the extreme end of aerobic training in marathoners and triathletes, although it is not unheard of in fitness enthusiasts.) 
• As above, unless diet and program are managed with knowledge, immune system dysregulation and illness may result with extreme training. (Moderate aerobic training improves immune system response.)
• Helps regulate body weight, blood glucose and triglycerides and cholesterol metabolism in conjunction with a healthy diet.

Interval Training

Interval training is shorter bursts of exercise, often at high intensity, with breaks in between. Running fast laps of an oval, resting, then doing it again is an example. This trains you to continue to do fast exercise at a high intensity. Fast interval training is essential for team sports, sprints, medium distance races and even endurance races. Interval training can be an important component of a fat loss program.

• Builds the anaerobic system and the lactic acid system.
• Improves the aerobic system by increasing VO2 max.
• Uses a lot of comparative energy for time elapsed during any particular interval, but naturally, rest periods between intervals expend much less energy. One hour of interval training may not expend as much energy as an hour of steady state running, but it depends on the program.
• Interval training is likely to produce significant EPOC, perhaps in excess of steady-state aerobics depending on the program.
• A heavy program of interval training may also be catabolic unless nutrition, intensity and rest aspects are managed well.
• Immune system dysregulation may be even more likely with a poorly conceived high-intensity interval training program.
• Helps regulate body weight, blood glucose and triglycerides and cholesterol metabolism in conjunction with a healthy diet.

Weight Training

Weight training, resistance training or strength training is about lifting weights or alternative devices, including your own body weight, in order to improve strength and usually, build muscle.

• Builds muscle, builds or helps maintain bone, and enhances strength and balance.
• Weight training is a moderate form of exercise for energy expenditure. Sixty minutes of vigorous weight training uses 400 to 600 kcalories depending on intensity and time intervals between sets. Circuit type training may optimise energy expenditure.
• Muscle uses more energy than fat so extra muscle and less fat should increase metabolism slightly. This does not make a a huge difference in the scheme of things.
• If you work hard enough, weight training probably produces significant EPOC to ramp up the metabolism. But you can’t waltz around the gym lifting a few dog bone dumbbells now and then and expect to produce results. You need to work hard at weight like anything else.
• May  help regulate body weight, blood glucose and triglycerides and cholesterol metabolism in conjunction with a healthy diet. (Weight training won’t help in this context if you maintain a high body fat percentage, as some specialist weightlifters do.)

It’s worth doing all three of these types of exercise. Obviously, you need to concentrate on one if your sport demands it, but for general fitness, each provides an element of fitness not available from the other two.

My Top 3 Internet Fat Loss and Fitness Gurus

By Paul Rogers

I get to read a lot of articles from many different internet trainers, nutritionists and health and fitness experts. Sometimes it’s just curiosity and sometimes I really learn from what they have to say.

Although I mostly rely on my own research of the scientific literature for assessing the worth and veracity of any particular aspect of the preventive health sciences, expert writers and commentators can help by providing analysis, exploration and summary of what’s reasonably known about any particular subject;  from fat loss to muscle building and the prevention of the big three preventable diseases — cancer, heart disease and diabetes.

 As far as fitness, fat loss and nutrition are concerned, but not necessarily preventive health in its wider aspects, here are three guys I enjoy reading. That’s not to say there are not others of similar worth, especially academic and institutional professionals that specialise, but these guys have a good grasp of nutrition and fitness training combined with practical experience – and they also know how to convey a message with lucid communication. They all have their strengths and I might even disagree with a minor point here or there, but read up on their blogs and free articles and you will learn a lot about weight loss, fitness training and general nutrition for the masses — pretty much without any loony stuff or weird approaches — which is more than can be said for some other sites.

• Christian Finn’s Facts About Fitness
• Tom Venuto
• Lyle McDonald’s Body Recomposition

Each of them has something to sell but none are too pushy. And by the way, I don’t do commissions or affiliate stuff with these people at all. By all means buy their products, but they all have plenty of free content to keep you going for some time.

The 7 Mega Principles of Diet and Exercise for Fat Loss

By Paul Rogers

Yes, I am somewhat proud of the fact that if you do a Google search (at the main google.com site), an article of mine still comes up number 1 for the term fat burning. It’s an article I wrote for About.com Weight Training over 12 months ago. I am surprised at this because Google records about 3.1 million records for the search term ’fat burning’. And when you see all the goony, loony web sites and weight loss schemes and supplements and silly diets and downright ripoffs that plague the internet, it does seem unlikely that a truthful and accurate article still has a chance of getting to the top. Three cheers for Google.

In any case,  for Christmas I’ll do the KISS thing and “keep it simple, stupid” by summarising the no-fail approach to weight loss that emphasizes fat loss and muscle maintenance. If it fails for you, then you are either eating too much, moving too little or have a genuine pathology or genetic disorder — and mostly this is rare as a cause of obesity.

7 Rules to Rule Them All

1. Don’t sweat the small stuff. The number 1 rule is not to get hung up on the trivia. This is the 90/10 rule or whatever you want to call it. The idea is that you must concentrate on putting most effort into doing the things that bring you most return and success. It’s okay to  follow up on the small stuff after you get the big picture correct. Don’t get distracted by “insider secrets” or any of that web marketing hype. There are no insider secrets to achieving and maintaining normal weight. But that doesn’t mean there are not serious challenges.
2. It’s the calories stupid! Even though I saw Tom Venuto use this phrase recently, I first used it in 2001 in a book I wrote called The Organic Factor. Even so, I’m sure quite a few people  have come up with this independently, it’s so very obvious. This is one of the pieces of “big stuff” that I refer to in the rule above. You need to get into negative energy balance territory (but not too negative) to lose weight and that means eating less and exercising more. And the best way to cut calories? Limit animal fats, added fats, added sugars, alcohol, and reduce  excessive portion sizes.
3. Adopt a lifestyle. Most diets will work for a short while – low-carb, low-fat, meal replacement shakes, you name it. If you take in less than you expend in energy, you will lose weight. However, you need to find an eating and exercise pattern that suits you, that works, and that you can adopt more or less every day of your life.
4. Do regular aerobic Exercise. Aerobic exercise is walking, running, treadmill, cycling, swimming, class aerobics and  rowing. You need to put some effort in so that you puff and sweat to some extent. Do this at least 5 times a week, for at least 30-40 minutes, even if it’s walking fast around the block.
5. Do regular weight training. Get to a gym or buy some dumbbells and a bench for home and do at least 2 sessions of weight training each week. It helps maintain muscle and bone while you lose fat and builds strength, flexibility and mobility for the future.
6. Move more at home and work. Under-rated and misunderstood, this is the science of NEAT or “non-exercise activity thermogenesis.” Moving more at home or work builds a feedback system that upregulates your metabolism. Get a pedometer and try to rack up 5,000 steps each day. It can be gardening, housework, playing with kids, lunchtime walks at work, stair walking, anything in addition to programmed exercise. Upper-body movement counts as well.
7. Get a brain plan. Tackle weight loss as a personal project. Keep a diary, set goals, review your progress each week, do lots of internal head talk, adjust your approach when necessary, be patient, stick to a lifestyle you can tolerate, and get encouragement from friends or a group.

That’s the nub of it. No secrets, no surprises. Good luck.

What You Don’t Know About Saturated Fat That Could Harm You

By Paul Rogers

What you probably do know is that most dietary recommendations say that you should keep your consumption of saturated fat and cholesterol in food low in order to lower your blood cholesterol and consequently your risk of heart disease.

The usual recommendations are that saturated fat should be no more than 10% of total calories and cholesterol less than 300 milligrams each day – and for people with existing signs of heart disease, less than 7% saturated fat and under 200 milligrams of cholesterol each day.

If you read widely of internet health and nutrition sites, you may also be aware that fringe movements exist that say this is not true; that it’s a government conspiracy and so on, and that saturated fat and cholesterol are as harmless as soft fruit. You can read one of my responses to that. It’s surprising how many otherwise knowledgeable pundits get taken in by this stuff.

What you may not know is that too much saturated fat in the diet has other adverse effects beyond how it raises blood cholesterol. Here is a short summary.

Saturated Fats Cause Dementia

Here is what one research team has to say about saturated (and trans) fat and cognitive function.

“Diets high in fat, especially trans and saturated fats, adversely affect cognition, while those high in fruits, vegetables, cereals, and fish are associated with better cognitive function and lower risk of dementia. While the precise physiologic mechanisms underlying these dietary influences are not completely understood, modulation of brain insulin activity and neuroinflammation likely contribute.” (Ann N Y Acad Sci. 2007 Oct;1114:389-97.)

And another:

“Moderate intake of unsaturated fats at midlife is protective, whereas a moderate intake of saturated fats may increase the risk of dementia and AD, especially among ApoE epsilon4 carriers. “ (Dement Geriatr Cogn Disord. 2006;22(1):99-107. )

Saturated Fats Cause Insulin Resistance

This conclusion provides a pointer to findings from several similar studies:

“A change of the proportions of dietary fatty acids, decreasing saturated fatty acid and increasing monounsaturated fatty acid, improves insulin sensitivity . . . ” (Diabetologia. 2001 Mar;44(3):312-9.)

And:

“Therefore, prevention of the metabolic syndrome has to be targeted . . . and . . . to improve insulin sensitivity and associated metabolic abnormalities through a reduction of dietary saturated fat, partially replaced, when appropriate, by monounsaturated and polyunsaturated fats.” (Clin Nutr. 2004 Aug;23(4):447-56.)

 Saturated Fat Slows Blood Flow in the Arteries

Here is what recent studies found about how saturated fat essentially clogs the arteries. (The endothelium is the layer of cells lining the inside of blood vessels and arteries. It is important in regulating blood flow.)

“High SFA (saturated fat) caused deterioration in FMD (flow-mediated dilation) compared with high PUFA, MUFA, or CARB diets. Inflammatory responses may also be increased on this diet.” (Arterioscler Thromb Vasc Biol. 2005 Jun;25(6):1274-9.)

And:

 ”Consumption of saturated fat reduces the anti-inflammatory potential of HDL and impairs arterial endothelial function. In contrast, the anti-inflammatory activity of HDL improves after consumption of polyunsaturated fat.” (J Am Coll Cardiol. 2006 Aug 15;48(4):715-20.)

And:

“Consumption of an SAFA-rich meal is harmful for the endothelium, while a MUFA-rich meal does not impair endothelial function in subjects with type 2 diabetes.” (Diabetes Care. 2008 Dec;31(12):2276-8.)

Overall, you should be able to see that the case against too much saturated fat in the diet is convincing – one way or another — and it’s not just about cholesterol. Bear in mind that vegetable sources of saturated fat are not inconsequential. Olive and soy oil are about 15%, corn and sunflower about 12% and peanut oil around 20%. However, consuming saturated fat and cholesterol together in animal foods may present the greatest combined risk, and whole nuts or seeds, even with some saturated fat, the least risk.

- Parrott MD, Greenwood CE. Dietary influences on cognitive function with aging: from high-fat diets to
healthful eating. Ann N Y Acad Sci. 2007 Oct;1114:389-97. Review.
- Laitinen MH, Ngandu T, Rovio S, et al. Fat intake at midlife and risk of dementia and Alzheimer’s disease: a
population-based study. Dement Geriatr Cogn Disord. 2006;22(1):99-107.
- Morris MC, Evans DA, Bienias JL, et al. Dietary fats and the risk of incident Alzheimer disease. Arch Neurol. 2003 Feb;60(2):194-200. Erratum in: Arch Neurol. 2003
- Vessby B, Unsitupa M, Hermansen K, et al. Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: The KANWU Study. Diabetologia. 2001 Mar;44(3):312-9.
- Riccardi G, Giacco R, Rivellese AA. Dietary fat, insulin sensitivity and the metabolic syndrome. Clin Nutr. 2004 Aug;23(4):447-56. Review.
- Keogh JB, Grieger JA, Noakes M, Clifton PM. Flow-mediated dilatation is impaired by a high-saturated fat diet but not by a high-carbohydrate diet. Arterioscler Thromb Vasc Biol. 2005 Jun;25(6):1274-9.
- Tentolouris N, Arapostathi C, Perrea D, et al. Differential effects of two isoenergetic meals rich in saturated or monounsaturated fat on endothelial function in subjects with type 2 diabetes. Diabetes Care. 2008 Dec;31(12):2276-8.
- Nicholls SJ, Lundman P, Harmer JA, et al. Consumption of saturated fat impairs the anti-inflammatory properties of high-density lipoproteins and endothelial function.J Am Coll Cardiol. 2006 Aug 15;48(4):715-20.

The Fitness Wars Are Futile

By Paul Rogers

I’ve put up a permanent page called Fitness Wars because I thought it should be a little “sticky.” It discusses the very strange culture of strength trainers who seem to react to cardio and aerobics with a crucifix held at arms length.

It’s a very odd response to a very important component of health and fitness conditioning and wellbeing programming.

Anyway, I’ve explored some of the origins of this antagonism and I take a look at aerobic conditioning in this context.

Dioxins in Food and Water Could Cause Diabetes

By Paul Rogers

I’ve been aware of an increasing number of recent studies that seem to show that the chemical pollutants called POPs – dioxins and similar compounds – could be at least partly responsible for the current epidemic of type 2 diabetes. Now it’s not conclusive, but some aspects of these investigations are certainly interesting. Like the fact that when controlled for dioxin content of tissue, even obese people were at no higher risk of type 2 diabetes if their dioxin levels were low. This could be a chance occurrence, or other factors could cause this to occur, but overall there are some compelling aspects to this research.

Here is what one author had to say:

“The strong associations seen in quite different studies suggest the possibility that exposure to POPs could cause diabetes. One striking observation is that obese persons that do not have elevated POPs are not at elevated risk of diabetes, suggesting that the POPs rather than the obesity per se is responsible for the association. ” [Rev Environ Health. 2008 Jan-Mar;23(1):59-74. Review.]

POPs are “persistent organic pollutants.” This class of pollutants includes dioxins, PCBs, DDT, DDE and many chlorinated organic pesticides. They accumulate in your body and in the fat of the animals we eat.

History of Dioxins and Diabetes

Some years ago I worked in occupational and environmental health and safety, advising on toxic chemicals and health. As well as working to establish the first chemical list for Australia’s National Pollutant Inventory, I also helped out the local Vietnam vets with their Agent Orange herbicide case. Much of the finer detail of the toxic risk assessments involved dioxins — exotic chemical contaminants that result from chemical manufacture and combustion. Levels of dioxin were very high in Agent Orange. There are over 200 varieties of dioxins, furans and polychlorinated biphenyls (PCBs) – chemicals with somewhat similar structure and varying toxicities to humans. Sometimes the toxicity of these dioxin-like chemicals are referred to collectively with ‘toxic equivalents’ or TEQ.

Studies of manufacturing workers exposed to dioxins and similar compounds had already revealed a higher incidence of diabetes, and animal tests had confirmed this possibility to some degree.

The early emphasis of dioxin toxicity research was on birth defects and cancer. However, it took some time for the US Veterans Affairs Department to acknowledge limited evidence in support of a connection of Agent Orange exposure with type 2 diabetes, to the extent that disability pensions are now paid on this basis.

Other pieces of research seem to fit the puzzle. It seems that endocrine disrupting chemicals in general, especially ones that persist in the environment, are associated with diabetes. And a most recent research study suggests that the much-publicized plastics residue bisphenol-A is also possibly involved.

POPs and Diabetes: What You Can Do

While these contaminants are everywhere – from the Antarctic to the purest looking lake water – they also contaminate food by accumulating in animal fats – and which we consume in meat, chicken, dairy and fish products and fats.

If you want to reduce  your intake, you really need to either find wild or organic and lean products from pristine places, or reduce your intake of animal foods, especially fat, or perhaps do a combination of both. This issue is also another reason why high-meat and fat diets like Atkins low-carb can be a recipe for disaster. And as for those so-called diet gurus who say we should eat more saturated fat . . . here’s a very good reason not to.

- Rignell-Hydbom A, Rylander L, Hagmar L. Exposure to persistent organochlorine pollutants and type 2 diabetes mellitus. Hum Exp Toxicol. 2007 May;26(5):447-52.
- Rylander L, Rignell-Hydbom A, Hagmar L. A cross-sectional study of the association between persistent organochlorine pollutants and diabetes. Environ Health. 2005 Nov 29;4:28.
- Ropero AB, Alonso-Magdalena P, García-García E, Ripoll C, Fuentes E, Nadal A. Bisphenol-A disruption of the endocrine pancreas and blood glucose homeostasis. Int J Androl. 2008 Apr;31(2):194-200. Epub 2007 Oct 31. Review.
- Wang SL, Tsai PC, Yang CY, Leon Guo Y. Increased risk of diabetes and polychlorinated biphenyls and dioxins: a 24-year follow-up study of the Yucheng cohort. Diabetes Care. 2008 Aug;31(8):1574-9. 2008 May 16.
- Michalek JE, Pavuk M.  Diabetes and cancer in veterans of Operation Ranch Hand after adjustment for calendar period, days of spraying, and time spent in Southeast Asia. J Occup Environ Med. 2008 Mar;50(3):330-40.

Recommended Dietary Intakes – Do You Need Supplements?

By Paul Rogers

Here’s a quick definition of RDIs — or RDAs as they are called in some countries.

Recommended Dietary Intakes (RDIs) (or allowances, RDA) are the levels of intake of essential nutrients considered, in the judgment of national health and nutrition authorities on the basis of available scientific knowledge, to be adequate to meet the known nutritional needs of practically all healthy people.

RDIs are given for vitamins, minerals, protein and some fats, and for different life stages, and pregnancy, and are usually daily quantities. They represent the needs for sustenance and avoiding deficiency disease.  See examples for Australia and the US.

Now that sounds simple enough, but unfortunately the RDIs and other measures of nutritional adequacy are widely misunderstood. That definition above does not imply that the RDIs are the “minimum” quantity required to stave off malnutrition or starvation.

In calculating RDIs, a safety margin is used so that biological differences from person to person can be accommodated. It may be that some individuals have less of a margin than others, but overall, the RDIs and RDAs are designed to exceed the minimum requirements for just about everyone, significantly. The idea that they are minimum values finds great comfort in the vitamin and mineral supplement industry of course.

Optimising Diets for Chronic Disease Risk

 Even so, there is recognition that higher intakes may help prevent some chronic diseases. To be fair, this is likely to be where misunderstandings occur. For example, the RDI for vitamin C is 45 milligrams/day, yet the suggested target for reducing chronic disease risk is 220 milligrams/day — quite a difference. Folate is another example where the suggested dietary target or SDT is much higher than the RDI.

Other Standards in Nutrient Reference Values

Although terminology can differ from country to country, here is a full list of acronyms worth noting within the broad range of nutrient reference value (NRV) or dietary reference intake (DRI) standards as applicable in the US, Canada and Australia based on the Institute of Medicine proceedings.

• EAR (Estimated Average Requirement). A daily nutrient level estimated to meet the requirements of half the healthy individuals in a particular life stage and gender group.
• RDI (Recommended Dietary Intake). The average daily dietary intake level that is sufficient to meet the nutrient requirements of nearly all (97–98 per cent) healthy individuals in a particular life stage and gender group.
• AI (Adequate Intake – used when a recommended dietary intake cannot be determined). The average daily nutrient intake level based on observed or experimentally-determined approximations or estimates of nutrient intake by a group (or groups) of apparently healthy people that are assumed to be adequate.
• EER (Estimated Energy Requirement). The average dietary energy intake that is predicted to maintain energy balance in a healthy adult of defined age, gender, weight, height and level of physical activity, consistent with good health. In children and pregnant and lactating women, the EER is taken to include the needs associated with the deposition of tissues or the secretion of milk at rates consistent with good health.
• UL (Upper Level of Intake). The highest average daily nutrient intake level likely to pose no adverse health effects to almost all individuals in the general population. As intake increases above the UL, the potential risk of adverse effects increases.
• AMDR (Acceptable Macronutrient Distribution Range). An estimate of the range of intake for each macronutrient for individuals (expressed as per cent contribution to energy), which would allow for an adequate intake of all the other nutrients whilst maximising general health outcomes.
• SDT (Suggested Dietary Target). A daily average intake from food and beverages for certain nutrients that that may help to prevent chronic disease.

Dietary Supplements

Supplementation has a role to play, but it needs to be done with caution, restraint and knowledge. The bottom line is that there will be individuals and population groups that do not meet the RDIs for individual nutrients.

• This can result from poor nutrition practices or even special diets poorly implemented. Low-carbers could be short on fibre and vitamin E; vegans on zinc, iron and B12; and very low-fat dieters on long chain omega-3.
• Populations in nutrient poor regions might lack iodine and selenium; and certain cultural habits like full body clothing can result in inadequate vitamin D intake in the absence of food or supplement sources.
• Athletes and heavy exercisers may need a modest increase in some nutrients, but this is usually accounted for by increased calorie intake — as long as the extra food is nutrient dense for the most part.
• Older people absorb vitamin B12 less well and this may require supplementation. The ill or infirm who do not get adequate sun exposure may require vitamin D supplements.
• Pre- and during pregnancy, folate supplementation is a useful reassurance against neural tube abnormalities.

However, not only is it likely wasteful to take mega-doses of supplements, it may even be unsafe. The recent scientific examination of vitamin E and beta carotene in high supplement doses has not yielded promise and has suggested adverse effects. If you feel you need to take an individual supplement or a multi, first check out the excellent information at the Office of Dietary Supplements at the NIH. then try not to exceed the RDI by more than a few times for any individual nutrient, unless there are indications that it’s safe and effective to do so.

Burn That Belly Fat With High-Intensity Training?

By Paul Rogers

A recent study by researchers at the University of Virginia found that high-intensity exercise training disposed of more belly fat in obese middle-aged women than lower-intensity training of the same energy expenditure.

The idea that doing high-intensity interval training burns off stubborn fat and visceral belly fat has been around for quite a few years. The premise has always lacked strong evidence in my opinion — or at least reasonable qualification. Any number of internet training and fat-loss gurus are promoting this idea.

What is High-Intensity Training?

First up, we need to get the concept straight. What exactly is the ’interval training’ or ‘high-intensity training’ or ’high-intensity interval training (HIIT)’ that we hear so much about?

Interval training is intermittent training, often near your maximum, in which you do a lap of an oval, or a spin on a bike, or 60 seconds on a treadmill very fast, then you recover, and do it again several times. That’s simple enough.

For example, I’m a masters sprinter and in training I might do 10 x 100 metres at 95% capacity, or 10 x 40 metres at 100% capacity. This is high-intensity interval training in real life. But I’ve been a marathoner and triathlete as well (don’t ask), and high-intensity training for those disciplines is mostly entirely different; say, 2km fast, 2km slow, 2km fast; or 6 x 400 metres at 90% capacity, or even, I might add, 5km at race pace, which is still high-intensity training, even if not interval training. And further, I know that if you run 40 to 60 miles a week in marathon or triathlon training you’ll burn fat . . . lots of it. So what’s this HIT stuff all about?

Early Investigations Were Not Adequate

One problem with some of the earlier studies was that they did not set a rule for what constitutes ‘high intensity’. The study I quoted above used lactate threshold to determine this, an excellent idea. And few earlier studies actually compared the different intensities for the same energy expenditure, which is what needs to be done to get a reasonable comparison.

You can’t just do 6 spins on a stationary bike for 30 seconds flat out and expect to burn the same amount of calories and fat as someone who does 30 minutes on the treadmill at 85% capacity, or even a 90-minute run at slow pace for that matter. Energy expenditure, which just about always includes some fat and glucose burning, is going to be a product of intensity X time for any physical activity. 

In that event, the best approach for fat loss and fitness goals is likely to be a combination of interval training, weight training and cardio at different intensities. Big surprise eh? No, that’s right, it’s not. It almost reflects the recent exercise guidelines issued by the US government for general health and fitness.

Persistent Abdominal Fat and How to Shed It

What the study above suggests is that high-intensity training just might be superior to to lower-intensity training, for equal energy expended, in removing belly fat, especially the visceral fat wrapped around the internal organs that has been shown to increase your risk of heart disease and type 2 diabetes. Naturally, you have to include a nutrition program with some calorie restriction as well.

Even though the study involved a small number of women, 27, it seemed to be well designed. And yet men might respond differently, as might the young or post-menopausal women. It’s an idea that has promise for designing exercise programs for the overweight and people with metabolic syndrome and diabetes and is well worth watching in the future. The main problem is one that is not going to be easily solved: that unfit, obese people are unlikely to take on high-intensity training by themselves and stick to it, despite what you see on The Biggest Loser.

Having said that, there is plenty of evidence that aerobic, cardio type programs help people lose fat in general — even some visceral fat — and aerobic exercise has additional benefits for cardiovascular protection. A combination of weights, cardio and HIT is likely to be the superior program if it can be tolerated.

The Best Type of High-Intensity Training for Obesity?

Heavy people exert quite a shock to the knees when they run long or hard. It’s a real injury concern. Running is often out of the question for obese people, let alone high-intensity running. For this reason, I favour cycle spin classes on a stationary bike. Doing this exercise in a group has advantages. The instructor will encourage hard work, but it’s possible to set your own pace by adjusting resistance and peddle cadence if you get overwhelmed. You’ll get some high-intensity work threaded with lower-intensity cardio — an excellent workout combo. A medical checkup is highly recommended for anyone moving from a sedentary lifestyle to high-intensity training.

The Diet Wars Really Are Over

By Paul Rogers

John Tierney over at TierneyLab recently had a bit to say about the New England Journal of Medicine study that compared an American Heart Association low-fat diet with Atkins and Mediterranean diets.

I’ve discussed the details and the implications in a longer page post called Diet Wars, but the upshot of this and many other bits and pieces of nutrition research from recent times pretty much suggests that we stop wasting time debating low-fat or low-carb or in between and get on with recommending a healthy eating pattern that spans a wider macronutrient range for fat, protein and carbohydrate.

Let’s get the faddists, fanatics and false prophets on the run.

Does Stretching Work for Injury Prevention or Performance?

By Paul Rogers

If you’ve been involved in any sort of physical activity for fitness or sports, you probably know that ’stretching’ is highly recommended for the following reasons:

• Increase or maintain flexibility to prevent injury and increase mobility for day-to-day living
• Prevent injury during sports and exercise activity
• Increase performance in sport
• Offset muscle soreness after exercise

It seems to make sense doesn’t it? You feel that muscle let go and you think to yourself: “if only that muscle was a little more flexible, that would not have happened.”

The trouble is, much of the value of stretching got taken for granted over many decades and few scientific studies were undertaken to confirm what everyone assumed was correct: you must stretch.

Now, some of that scientific work on stretching has been done and it’s not quite as simple as logic would have us believe.

Maintain flexibility

To cut to the chase, stretching on a regular basis, perhaps daily, seems to be a good idea for everyone. Regular stretching probably has benefits for increased mobility, balance and injury prevention, especially as we age.

Prevent injury during exercise and sports

While regular stretching of various types may help athletes overall, stretching before or after an event or workout has mixed support for injury prevention, which I’m sure comes as a surprise to many. We all do it in some form because it makes us feel ready to compete. Benefits may be more psychological than physical. However, some recent review studies have been more positive, especially in relation to muscle-tendon injuries. Inadequate study design and confusion of the terms ’stretching’ and ‘warmup’ seems to have confounded much of the early science.

Enhance performance

Static stretching, it seems, may even impair performance in power sports like sprinting and jumping by interfering with optimum stretch-shortening cycle. It’s best not to confuse static stretching with warmups, in which dynamic stretching probably has a place.

On the other hand, some sports like gymnastics and dance require extreme flexibility and the same rules may not apply.

Overall, static, passive of PNF (proprioceptive neuromuscular facilitation ) stretching close to your sport or activity — before or after — seems to have little going for it in relation to performance benefit.

Prevent muscle soreness

Soreness after an exercise session is called ‘delayed-onset muscle soreness’ or DOMS. Stretching before or after exercise has long been recommended as a way to reduce or prevent soreness. However, a review of studies in this area did not find any benefit from stretching for the prevention of muscle soreness. Warming up is something different and has more calculable benefits.

Summary of stretching

In summary, the best advice seems to be that we maintain a regular stretching program from day to day, warm up sufficiently before exercise and sport, including some dynamic stretches — leg swings, arm swings are a good example — then warm down with some further stretches, but don’t expect that either performance or muscle soreness will benefit from static stretching at exercise time.

I’m certain this will be debated for many years to come.

- Small K, Mc Naughton L, Matthews M. A systematic review into the efficacy of static stretching as part of a warm-up for the prevention of exercise-related injury. Res Sports Med. 2008 Jul-Sep;16(3):213-31.
- Hart L. Effect of stretching on sport injury risk: a review. Clin J Sport Med. 2005 Mar;15(2):113.
- Herbert RD, de Noronha M. Stretching to prevent or reduce muscle soreness after exercise. Cochrane Database Syst Rev. 2007 Oct 17;(4):CD004577. Review.

Next Page »

• Archives

  Select Month July 2009 June 2009 May 2009 April 2009 March 2009 February 2009 January 2009 December 2008 November 2008 October 2008 September 2008 August 2008 July 2008 June 2008

 

 

Subscribe RSS

Enter email address for weekly free newsletter:

[Privacy respected]

• Categories

  Select Category Cancer Diabetes Fat loss Fitness Food Heart Disease Lifestyle disease Nutrition Physical activity Uncategorized

• Recent Posts

  • Survival of the Fittest
  • Acid and Alkaline Foods – What Are They?
  • Are Antioxidants Finished as Dietary Supplements?
  • Prevention and Management of Diabetes with Lifestyle Change
  • Red Meat and Chronic Disease
  • Best Exercises to Prevent Osteoporosis
  • Increasing HDL Cholesterol is the New Focus
  • Losing Weight and Keeping It Off
  • The Top 6 Lifestyle Tips to Prevent Heart Disease
  • A Low-Fat Mediterranean Diet – Is It Possible?
  • Steady State v Intervals v Weight Training
  • My Top 3 Internet Fat Loss and Fitness Gurus
  • The 7 Mega Principles of Diet and Exercise for Fat Loss
  • What You Don’t Know About Saturated Fat That Could Harm You
  • The Fitness Wars Are Futile