My Top 3 Internet Fat Loss and Fitness Gurus

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

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.

Dioxins in Food and Water Could Cause Diabetes

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?

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.

The Diet Wars Really Are Over

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.

How to Boost Immunity With Diet and Exercise

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.

The Truth About Organic Food

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.

Low-Carb Diets Make You Dumber and Slower

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

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!

1. 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.
2. 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.
3. 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.
4. 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

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:

1. 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.
2. 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.
3. 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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