My Top 3 Internet Fat Loss and Fitness Gurus
By Paul RogersI 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.
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.
What You Don’t Know About Saturated Fat That Could Harm You
By Paul RogersWhat 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.
Recommended Dietary Intakes - Do You Need Supplements?
By Paul Rogers
Photo by Untitled Blue
Here’s a quick definition of RDIs — or RDAs as they are called in some countries.
Optimising Diets for Chronic Disease Risk
Other Standards in Nutrient Reference Values
- 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.
How to Boost Immunity With Diet and Exercise
By Paul Rogers
Photo by ktylerconk
How many times have you seen an ad for some wonder ‘erb or other that’s supposed to boost the immune system. It’s echinacea today and some Chinese herb the next, as well as a vast array of products that the supplement industry claim “support the immune system” — whatever that means.
Diet and Immunity
I’m not suggesting that diet and nutrition don’t have an important role to play in maintaining a healthy immune system. Meeting the recommended intake of macronutrients, vitamins and minerals and fats, and consuming copious quantities of antioxidant nutrients as part of healthy eating is bound to promote good immune system function — as far as it goes. However, the evidence for consuming individual dietary components or special foods or supplements beyond the RDI (recommended dietary intake) is mostly speculative or at least inconclusive.
Exercise and Immunity
If you follow a healthy lifestyle approach with healthy eating and a program of physical activity, here are a few things to note about how the immune system responds to exercise:
- A regular, low to moderate intensity exercise habit is associated with a reduced incidence of infection compared with those who do very little exercise or physical activity.
- Heavy, and or prolonged exercise training can impair the immune system, possibly leading to susceptibility to infection, particularly in a period of up to 24 hours after a heavy training session or event.
- Exercising at high intensity for prolonged periods without food — 90 minutes and beyond for example — may make you especially vulnerable to infection as a result of immune system depression.
- Consuming carbohydrate at the rate of 30-60 grams an hour during intense and prolonged exercise can help to maintain immune system function. That’s 1-2 sports drinks and hour or equivalent. (One drink is probably adequate for most situations except for extreme conditions and intensity.)
- Meeting your daily requirements for micronutrients like zinc, iron, and B and C vitamins is essential. Although a multivitamin supplement may help, consuming mega quantities of vitamins and minerals may be counterproductive. See article on Vitamin C and training adaptation.
- A recent review confirmed the value of carbohydrate supplementation and a possible role for vitamin C (note caution above), but no other supplement showed up as useful for heavy exercisers.
It’s worth noting the value of carbohydrate to immunity in a balanced diet and exercise program. Low-carbohydrate intake with low blood glucose, plus the stresses of exercise, increases cortisol production to the point where the immune system is compromised. Low-carb, high-fat diets, especially saturated fat, are not appropriate if you have a robust exercise program. In addition, saturated fat has been shown to impair immune response. Low-carb is not where you want to be if you exercise a lot.
J Sports Sci. 2004 Jan;22(1):115-25. Exercise, nutrition and immune function. Gleeson M, Nieman DC, Pedersen BK.
JEur J Clin Nutr. 2007 Apr;61(4):443-60. Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis. Moreira A, Kekkonen RA, Delgado L, Fonseca J, Korpela R, Haahtela T.
Scand J Immunol. 2008 Jul;68(1):30 42. Differential effects of a saturated and a monounsaturated fatty acid on MHC class I antigen presentation. Shaikh SR, Mitchell D, Carroll E, Li M, Schneck J, Edidin M.
Food and Fitness Science Roundup
By Paul RogersFor this regular roundup, I try to find work that tells us something significant or new in the context of the field of study.
New Recommendations for Vitamin D Intake for Children from the American Academy of Pediatrics
A recommendation for a doubling of recommended dietary intake of an essential nutrient for any population sector is substantial news in nutrition science. The AAP list the reasons and the strategy here.
http://www.aap.org/pressroom/nce/nce08vitamind.htm
Coffee Drinking Does not Raise Mortality
Up to 6 cups a day and risks were still normal and even slightly lower than the consumers of much more moderate quantities. Adjustment of cardiovascular risk seems to be the difference — perhaps by lowering the risk of type 2 diabetes?
Ann Intern Med. 2008 Jun 17;148(12):904-14. The relationship of coffee consumption with mortality. Lopez-Garcia E, van Dam RM, Li TY, Rodriguez-Artalejo F, Hu FB.
Also see: Does Coffee Kill or Cure?
Red Wine Seems to Cut Risk of Lung Cancer
What? Not another reason to drink red wine! The authors do counsel against excessive consumption.
Cancer Epidemiol Biomarkers Prev. 2008 Oct;17(10):2692-9. Alcoholic Beverage Intake and Risk of Lung Cancer: The California Men’s Health Study. Chao C, Slezak JM, Caan BJ, Quinn VP.
Vitamin C Interferes with Training Adaptation and Performance
I noticed the possibility of this a few years ago while researching the utility of antioxidants like vitamin C to benefit athletic performance. Vitamin C seemed to inhibit phosphofructokinase, which is an important enzyme in glycolysis (breakdown and use of glucose for energy). Considering that many athletes and fitness buffs seem to take vitamin C supplements, it may be worth noting. Moderate dietary intake is likely not a problem. We need more information on this one before the panic sets in.
Am J Clin Nutr. 2008 Jan;87(1):142-9. Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance. Gomez-Cabrera MC, Domenech E, Romagnoli M, Arduini A, Borras C, Pallardo FV, Sastre J, Viña J.
Caffeine Plus Carbohydrate Increases Glycogen Storage
As far as I am aware, this is the first time this has been shown. About 500 mg caffeine is a lot of coffee though.
J Appl Physiol. 2008 Jul;105(1):7-13. High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine. Pedersen DJ, Lessard SJ, Coffey VG, Churchley EG, Wootton AM, Ng T, Watt MJ, Hawley JA.
New Glycemic Index and Load Tables
If you’re into the GI, you’ll need this. More on the GI in another article. I’m not a big fan.
Click through to here from the abstract and you can download the free tables.
Diabetes Care. 2008 Oct 3. International tables of glycemic index and glycemic load values: 2008. Atkinson FS, Foster-Powell K, Brand-Miller JC.
Check out the Food for Life, Fit for Life Training Program. Free download available.
The Truth About Organic Food
By Paul Rogers
Photo by bittenword
I’ve been a keen gardener most of my life, following a strong family tradition. We’ve grown everything from flowers and ornamentals to fruit trees and vegetables — with varying measures of success. Organic growing in a home garden, and wherever feasible commercially, just seems like sensible environmental management to me . . . and it’s especially applicable to home gardening. I’ve also written about organic growing and been a member of a growers group for decades.
Organics may not be the only solution
Even so, I’m not an absolutist, and I am a pragmatist . . . I accept that there may be other farming and cultivation systems that could indeed be regarded as “sustainable and healthy” even though they may not pass organic certification. But that’s not my argument here. I’m going to look critically at the notion of why you should buy organic food and whether the advantages stack up — give or take a few generalisations.
Here are the usual reasons for supporting organic food production:
- It’s healthier because few, and low-toxic pesticides are used and residues on crops are not a problem
- It’s healthier because organic food is higher in dietary nutrients
- It’s more sustainable because soil is managed better without chemical fertilizers
- It’s safer and sustainable because beneficial organisms like bees and predatory organisms and wildlife are not poisoned by pesticides
- It’s safer because humans are not poisoned by pesticides as they use them.
Pesticide residues
Even allowing for cheating, it is clear from testing that organic food has fewer residues of detectable pesticides than non-organic food. The issue is whether the presence of residues in non-organic food is a health hazard. Clearly, in some cases it is. The cases of aldicarb pesticide poisoning from melons in California is a classic case. This was only detected because of the severe symptoms. Many other cases are likely in which the victim has less acute symptoms and the cause remains unidentified. And, the effect of long-term exposure to small quantities of residues is unknown, but could be significant.
Testing for safe food. With the world food supply increasingly traded across borders, ensuring “clean” food by monitoring it for contaminants has become increasingly difficult. Recent issues in food safety in relation to food products imported from China make this all too clear.
Organic food has more nutrients
This is the one the professional agriculture, health and nutrition communities have resisted so strongly for so many years. In essence, it is a complex issue. To measure this accurately, you really need to set up controlled growing conditions for a reasonable comparison, and even though quite a few early studies showed advantages for organics in some nutrients like vitamin C, iron, omega-3s and a few other minerals, the design was often somewhat amateurish — until the European Union Newcastle University study came along. Read the results here: “Organic produce better for you”.
Variability abounds. The authors caution that variations in qualities exist across the organic and non-organic spectrum. What this might mean for you, as a purchaser, is that a badly grown organic apple could very well be inferior to a well-grown non-organic apple. One might expect that across a continuum of organic produce, the nutrient value may be higher, but don’t expect that any one purchase will give you that guarantee.
Phytonutrients finally. Over the years of this organic nutrient debate, the one thing that has mostly been absent is an evaluation of the non-vitamin and mineral nutrients. These are the antioxidants, the polyphenolics, carotenes, sulphur compounds, the omega-3s and many more that are known to be health-giving principles in foods. Finally, this also seems to have been answered. In the Newcastle University study:
They found levels of antioxidants in milk from organic cattle were between 50% and 80% higher than normal milk.
This is not surprising, overall, because Alyson Mitchell, associate professor and food chemist at the University of California, Davis, found exactly the same thing in her work analysing tomatoes. Soluble fertilisers, especially nitrogen, and strong pesticides may inhibit the plant production of phenolic compounds. See Mitchell again for a discussion.
One would have to say that early professional bias against the idea of organics having higher overall nutrient values, in a dietary sense, seems to have been ill-founded and perhaps influenced by various vested interests. However, this should not suggest that eating organic foods, even with a premium supply of antioxidants, results in superior health outcomes: that is yet to be proven.
Organic growing is more sustainable
As a general rule this is probably true, and is likely to be more so for smallholdings rather than large commercial enterprises. The definition and evaluation of “sustainability” is variable, but one issue is the recycling of inputs to the system versus importing inputs like organic fertilizers from elsewhere. Sustainability is about being able to make systems last without degrading the system.
Nevertheless, several recent studies — University of Michigan, the USDA and the FAO and others, have found that organics actually outperform conventional agriculture in measures of soil sustainability and biological sustainability — and may even approach the production efficiency of non-organic farms in some cases.
Safer for wildlife and diversity
New Scientist reports: “Organic farming boosts diversity”.
Organic farming increases biodiversity at every level of the food chain – all the way from lowly bacteria to mammals. This is the conclusion of the largest review ever done of studies from around the world comparing organic and conventional agriculture.
Enough said about that one.
Occupational health and safety
This is the sleeper issue in organic production. It receives less attention than other aspects. The human health legacy of toxic pesticides in developing nations has been monumental. And even in the developed nations, the misuse and overuse of pesticides has resulted in substantial impacts on human health. The US Agricultural Health Study has reported on some such results.
Here is what esteemed toxicologists Levine and Doull said about pesticide poisoning worldwide in 1992:
Global estimates of acute pesticide morbidity and mortality. Levine RS, Doull J. Rev Environ Contam Toxicol. 1992;129:29-50.
Mathematical models have projected increasing numbers of pesticide poisoning throughout the world, rising from 500,000 cases/yr in 1972 to 25,000,000 cases/yr in a 1990 estimate.
Summing up
Organic food is more expensive; you have to decide if it’s worth it. In addition, the science of organics is a bit fuzzy at times. Some modern pesticides actually have lower toxicity than approved organic pesticides. The more popular and affordable organic food becomes, the more we will see mainstream food manufacturers taking advantage of it. No folks, the organic pop tart is not a health food. Overall, though, organics is a neat package of environmental health and safety practice. I support it strongly.
Food for Life, Fit for Life - Lifestyle Training Course Released
Food for Life, Fit for Life - Prevent Diabetes, Heart Disease and Cancer is a set of training modules in lifestyle preventive health. It took me 12 months to write and it’s now available for licensing. You can download a free ebook version that describes the content. Here’s what’s included:
- Training and evaluation manual for course presenters
- 120 PowerPoint slides with notes and contemporary references
- Sample learner assessment questions for each module
- Fact sheets that can be used as handouts to clients/students
- Risk evaluation self-assessment handouts for nutrition, physical activity, diabetes, cardiovascular disease, and cancer
- Case studies for workgroups and workshops
- Glossary of terms
- Regular newsletter
- US and UK/Australia versions (spelling and units)
- Evidence based information, fully referenced
- Flexible licence conditions and regular, free updates for one year
- Access to a membership web site for support, updates and extra resources.
Background
I started writing this over 12 months ago as a tool to use for talks to clients and groups in fitness and personal training. Rather than the limited training course I had in mind at that time, it has now morphed into something more like a training ‘environment’ with support tools like handout risk assessments and case study tasks. I have plans to add more of these tools and content within the context of the course. For example, a basic ’sports nutrition’ module is near completion.
As a trainer-presenter, your options are varied. You could select various slides or modules for presentations ranging from 2 hours to 2 days to groups or even individual clients. The target audience could include lay people or professionals in various support roles in preventive health. Presenters could include dietitians, nutritionists, fitness trainers, practice nurses, physios, diabetes educators and any support professionals working in preventive and lifestyle health. Some skill in delivering an appropriate language and idiom to audiences with variable knowledge bases would be required by the presenter.
I’ve summarised the essential elements of lifestyle disease, meaning the risks with which we burden ourselves because of our behaviour in relation to food, nutrition and physical activity. Although I mention the roles of environment and genetics, this is not the focus of the program at this time, but I do have plans to add modules that address basic issues in environmental safety in relation to food quality. Any additional modules added are included in the updates available in the licence for one year.
The core elements are:
- Type 2 Diabetes
- Cardiovascular disease
- Cancer
- Obesity
- Motivational and behavioural change
- Nutrition
- Physical activity and exercise
For example, I’ve summarised the complete content of the WCRF/AICR Expert Report: Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective so that the essential points are clear.
Licences
At present, only one licence option is available. This locks the headers and footers and PowerPoint attributions to me and no changes are permissible. I will probably also offer a ‘professional licence’ under which the licensee has the right to modify the content and replace attribution and headers etc with their identity. This would allow the licensee, with some restrictions, to modify the content and to adjust any particular aspect that did not suit their purpose or premise.
Availability
I’ve created a free ebook (pdf) version of the course, featuring the PowerPoint slide headings with content from the notes of each slide. This delivers a summary version and illustrates the content quite successfully. Not everything is fleshed out of course.
The best way to get this is to fill out the email form on the front page of the web site — or on this blog at the top right. This will redirect to a download page after confirmation. You will then get an email advising when content is updated or added, including new web and blog articles. This would be no more frequent than once each week.
I hope you take a look at the free ebook and let me know what you think. Suggestions, comments and admonitions are, of course, welcome.
Low-Carb Diets Make You Dumber and Slower
By Paul Rogers
Photo courtesy Anosmia
Low-carb diets have had their share of weight loss success; and most of it can be attributed to dietary restriction of food choice. That’s how most restrictive diets work, from low-fat to low-carb and vegan: tell people they can’t eat something that’s clearly identifiable, and they will lose weight because choice is curtailed and they find it easier to eat fewer calories.
The trouble starts when they find they can’t maintain such a restrictive regimen — and then they get discouraged, guilty, and the relapse occurs.
But what if low-carb dieting helped you lose weight for the time being, but actually inhibited your personal performance in day-to-day living? Would you continue with it as a lifestyle choice?
What I’m about to discuss does not necessarily apply to moderately low-carb diets, but mostly to ketogenic diets, in which carbohydrate intake is usually less than 20 percent. Even so, there is a possibility that the effects apply across a continuum of low-carb eating from very low to low.
And those adverse effects? Low-carb makes you think slower and move slower.
Low Carb Makes You Dumber
In a study in 2007 in the American Journal of Clinical Nutrition, researchers compared the cognitive abilities of dieters on a low-carb, high-fat (LCHF) diet with another group of dieters on a high-carb, low-fat diet (HCLF) . Here is what they found:
However, the IT test score (a measure of the speed of visual information processing) was affected by diet composition. The results showed that participants consuming the LCHF had significantly less improvement in the minimum stimulus time required to make a correct response than did those consuming the HCLF diet . . . Our findings are consistent with those of an earlier study in obese women showing that performance of a complex, cognitively demanding task assessing mental flexibility was significantly worse after the consumption of a very-low-energy, low-carbohydrate, ketogenic diet than after the consumption of an isocaloric, nonketogenic diet with higher carbohydrate and lower fat content. Similarly, the treatment of young rats with a ketogenic LCHF diet for 1 month resulted in severe cognitive impairment, and a series of rat studies showed that the chronic ingestion of a high-fat diet, in particular a high-saturated-fat diet, can adversely affect cognitive performance.
Low Carb Makes You Slower
In a study in the Journal of the American Dietetic Association in 2007, a team of investigators measured the fatigue and perceived effort of one group of dieters on a ketogenic low-carb diet and another group on a diet with much higher quantities of carbohydrate. Here’s what they concluded:
These pilot data indicate that ketogenic, low-carbohydrate diets enhance fatigability and can reduce the desire to exercise in free-living individuals.
This is not surprising because athletes know that glucose (and phosphocreatine) supply energy at a rate that supports fast, high-powered activities, whereas fat and ketones can only supply energy at a rate biochemically rapid enough for mostly slower activities.
Evidence from the Paleolithic
Now, you might think that would be a good place to leave this discussion — the evidence is reasonably clear — but just for speculative fun, let’s take a look at our evolutionary pre-history and the diets of emerging Homo sapiens — modern humans — in the Paleolithic period of evolution.
About 800,000 years ago, primates moved out of Africa to the north and into Europe to colder climates. This early pre-human form was called Homo erectus, and this species probably evolved into Homo neanderthalis, the Neanderthals, while erectus lived on as a parallel species.
The curious thing is that a second migration of early humans north from Africa started about 50,000 years ago and spread throughout Europe and beyond. It seems that this smart new species, Homo sapiens or ‘intelligent human’, was much more intelligent than earlier species such as erectus and neanderthalis. As far as evolutionary science can establish, Homo sapiens swept all before it and replaced the Neanderthals and erectus with modern humans throughout the world. The other species were out-competed and did not survive.
Paleo Diets and the Evolution of Power and Intelligence
Enthusiasts of Paleo dieting like to contend that early humans were very healthy on a diet mostly of meat, vegetables and some fruit, but virtually no grains or tubers — that is, a low-carbohydrate diet. However, it’s pretty clear that early humans started to eat grains about 20,000 years ago, perhaps earlier, and, according to Richard Wrangham, Elizabeth Pennisi and others, probably ate tubers well before then. See Did Cooked Tubers Spur the Evolution of Big Brains?
Paleontologists have speculated as to why Homo sapiens so dominated the other species in Europe and beyond as they moved into their territory from 50,000 years ago.
Here’s where I speculate that the burgeoning consumption of carbohydrate foods in the form of tubers and grains in East Africa, the cradle of early humans, fed a growing brain that thrives on glucose. Glucose from carbohydrates supplied abundant energy substrate for the evolving brain to build those complex neural networks that we know provides the complex reasoning capabilities of modern humans.
Carbohydrate foods were abundant in the East African savannah. As Wrangham points out: “Today, there are 40,000 kilograms of tubers per square kilometer in Tanzania’s savanna woodlands.” The book The Lost Crops of Africa, documents the prolific grain resources in this region. It would be unlikely if the evolving Homo sapiens did not take advantage of these abundant food resources at some time.
The Neanderthals, by comparison, most likely had a more limited food supply, relying mostly on meat and some vegetables and fruits in season, and eggs but fewer carbohydrate resources, especially in the cold north.
I think it’s a fair bet that Homo sapiens, as they moved north out of Africa from 50,000 years ago, armed with complex brains fueled by rapidly accessible glucose from carbohydrate food resources, simply out-competed the slower moving and thinking Neanderthals and the remaining Homo erectus. Not only were modern humans smarter, they probably moved faster as well.
The thing is, we can still simulate the best qualities of the diets of our ancestors, which were most likely characterised by being low in saturated fat, high in plant foods and fibre, and with sufficient carbohydrate to keep us out of ketosis and to fuel the powerful movement and activity required for good health and fitness.
High carb. Simply smarter, faster.
American Journal of Clinical Nutrition, Vol. 86, No. 3, 580-587, 2007
J Am Diet Assoc. 2007 Oct;107(10):1792-6.
How the Cholesterol Skeptics Can Harm You
By Paul Rogers
Pic courtesy jslander
Do a search for ‘cholesterol and heart disease’ in Google and you will see that many of the results in the first few pages are from sites that dispute the current medical view that cholesterol is a major factor in causing heart disease.
Some of the advocates of this position are well known ‘alternative’, or at least fringe movements that have a particular dietary barrow to push. Many belong to the low-carb brigade, indigenous diets advocacy, Paleo nutritionists, and sadly, some bodybuilders and weight trainers and men’s health advocates. And, of course, it should be said that many reputable people within these movements do not accept the ‘cholesterol myth’ line.
Cholesterol is a factor in heart disease and these people are dangerously wrong. They rely on dumbing down a complex scientific issue to impress a gullible audience. I could write a long review of this issue, fully supported by references, but I won’t waste my time, or yours. Here are a few crucial points to consider.
It’s the Cholesterol, Stupid!
- In the condition familial hypercholesterolemia (FH), individuals have naturally very high cholesterol levels as a result of a genetic abnormality. If undiagnosed, or without treatment, such people can die of heart attacks in childhood or in early adulthood depending on the severity of the condition. Brown and Goldstein won the Nobel Prize for their work on cholesterol, HF, and how cholesterol causes cardiovascular disease. The science of HF alone, should be enough to send the cholesterol skeptics packing — but still they persist.
- Although I am no promoter of pharmaceutical company interests per se, there is little doubt that statin medications improve heart disease conditions and fatal outcomes in people with high cholesterol by a combination of lowering LDL cholesterol and probably raising HDL cholesterol. The evidence is just too overwhelming. In fact, in recent years, the cholesterol skeptics have subtly shifted their attacks from “cholesterol does not cause heart disease” to, “saturated fat does not cause heart disease”, which is a softer target for them considering the complexities of different chain length saturated fats and the interactions of mixed diets.
- The skeptics like to juggle the medical literature to try to show that there is no valid evidence linking high cholesterol to heart disease. However, it’s not in dispute that heart disease is dramatically low in healthy populations with total cholesterol levels under 150 mg/dL or 3.9 mmol/L. Cardiovascular disease rises with increasing total cholesterol, and especially LDL cholesterol, in most populations.
- Even so, some populations in some countries seem to defy this trend, and these are the people the skeptics concentrate on when delivering their message. The thing to remember is that heart disease is multifactorial — that is, cholesterol may only be one factor among several, even though it is a major factor. Some populations will, through genetics or lifestyle, defy the atherogenic effects of higher cholesterol to some extent. This seems to be the case with the ‘French paradox’, in which French populations have much lower heart disease than other country groups with similar cholesterol levels. That does not mean that cholesterol is not a major factor in heart disease for most populations.
Overall, considering the established science of familial hypercholesterolemia, and the evidence from statin drug trials, including regression of plaque with cholesterol lowering, the evidence is so overwhelming for a dominant role of blood cholesterol in heart disease, and the influence of poor nutrition in raising blood cholesterol, that one can only assume the cholesterol skeptics have another agenda. I don’t know what it is, but it doesn’t take too much thought to come up with a list of industrial food interests that might benefit from this hogwash. Believe them at your peril.
Exercise Really is Necessary to Maintain Weight
By Paul Rogers
Pic from mikebaird
Recently I got into a discussion about whether exercise is really necessary in a weight loss program. The other guy was saying . . . ‘well, if you just cut calorie intake you’re going to lose weight . . . if you starve you lose weight; witness concentration camps and so on’. And of course, Gary Taubes has been stirring up the diet and exercise community with his irreverent, but flawed views.
It’s a trite argument isn’t it? If you don’t eat, or eat very little, inevitably you will lose weight, fat and muscle. We all know that; except that’s not what we’re really talking about today. If you’re overweight you need to find a pattern of living that allows you to maintain a normal weight and eat well enough so that you enjoy life without having to do “diets”.
What I recommend is moderate calorie restriction in conjunction with a substantial increase in physical activity. And I’m not alone. Increasingly the science supports this, as do many successful weight losers.
Calorie-restricted diets
The trouble with low-calorie diets by themselves is threefold:
- You reset your metabolism — downward. This is diet-induced thermogenesis. The body senses a low-calorie environment and decides to reduce its basal energy expenditure. It’s a survival mechanism that’s evolved over thousands of years.
- On low-calorie diets you lose not only muscle, but bone as well. Okay, when you stabilise your weight you may get some of this back, but it’s not ideal.
- Without exercise, you don’t get all those other proven benefits like protection from heart disease and some cancers, improved bone density, mental health, and perhaps protection from dementias as well as a list of other benefits.
Proven as a practical approach
Professional physical activity guidelines have for several years recommended that one needs to exercise an hour a day for most days of the week to lose weight and to keep it off. This has recently been confirmed by a study of women published in the Archives of Internal Medicine
Not only that, but the US National Weight Control Registry – a program that keeps track of successful weight losers — found that most of their successful listers did just that: exercised for about an hour a day in addition to their day-to-day activities. It doesn’t have to be all high-intensity stuff, because many did a lot of walking.
Low energy density, high-nutrient foods
One way to trick the body into maintaining metabolism while you reduce calorie intake is to eat plenty of low energy density foods — along with the increase in exercise. That means fruit and vegetables, salads, soups, bowl foods, beans, lean meat and not too much fat, refined carbohydrates and sugars. This is a proven approach called Volumetrics, which originated with Barbara Rolls at Pennsylvania State University.
Giving the body plenty of fibre, water and bulk to deal with even though the calorie count is comparatively low, tends to keep that metabolism from dropping too much.
Exercise - the fourth macronutrient
Food pyramids increasingly include physical activity in their recommendations because the best evidence suggests that uncoupling physical activity from food consumption creates a body environment that is not ideal for weight loss and maintenance, or health. This also reflects an evolutionary state built over tens of thousands of years when early humans moved much more than we do today.
I understand that some people can’t do much exercise. The infirm, injured and invalid have additional challenges, but the effort may be just as important for many people in this situation.
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