William T Neville, General Practitioner. Another enlightened Medical Professional.

In December 2012 the British Medical Journal published a study regarding weight loss and low fat diets. It is a very detailed study and concluded the average weight loss amounted to 1.6kg. Hardly significant when you look at the growing obesity epidemics in many countries across the world. William T Neville, General Practitioner commented on the study and we publish his letter in full below. Normally we publish a short extract of other peoples work and give a link to the full or main article. For us lowcarb diabetics this letter illustrates concisely and exactly what we believe, and have proved to be successful for controlling our weight and type two diabetes beyond all reasonable doubt over almost five years.

Eddie

The study

Effect of reducing total fat intake on body weight: systematic review and meta-analysis of randomised controlled trials and cohort studies.http://www.bmj.com/content/345/bmj.e7666

10 December 2012

The comment

William T Neville, General Practitioner

This study confirms that reducing fat in the diet is of no benefit. A loss of just 1.6kg is of no significance to an overweight person. There is much research evidence that the best way to lose weight is to reduce carbohydrates at the same time as increasing fat from animal sources.

The mechanisms are well described by several authors [1, 2, 3, 4, 5, 6]. Carbohydrates stimulate insulin. Insulin stimulates fat storage. The amount of calories in food is irrelevant. Exercise does nothing for weight loss. Reducing carbohydrate intake reduces insulin levels and this allows fat to be metabolised. The start of the obesity epidemic can be dated to 14 January 1977 when Senator George McGovern announced publication of the first “Dietary Goals for the United States” which advised reduced fat consumption. People throughout the world cut out fat. Instead they ate more carbohydrates and obesity has increased ever since.

Trials comparing different diets show carbohydrate restriction to work best. An example is the Stanford A – Z trial [7]. The lead author, a vegetarian, described the result as a bitter pill to swallow. The success of any diet depends primarily on the degree to which carbohydrate intake is reduced.

There are other causes of obesity. Grains are the main source of carbohydrates and contain built in insecticide anti-nutrients called lectins. Amongst many harmful effects lectins bind irreversibly to insulin receptors and stimulate fat storage. Another action of lectins is to block the action of leptin, a hormone that increases satiety. The protein Gliadin in wheat attaches to opiate receptors in the brain which increases apatite [8]. Vegetable oils cause obesity because they have high levels of linoleic acid, an omega 6 fatty acid. A high ratio of omega 6 to omega 3 in cell walls results in stiffening of the cell wall and reduced numbers of insulin receptors. This leads to insulin resistance which causes weight gain. Sugar does not just represent empty calories [9]. The fructose component causes drastic metabolic changes such as hyperinsulinaemia with resulting obesity.

Eating more animal fat may increase cholesterol levels and people wrongly fear this will cause heart disease. Several well referenced books demolish the theory that cholesterol levels are related to heart disease [10, 11, 12, 13]. Meta-analysis confirms that saturated fat is harmless [14]. In fact, throughout Europe countries with the highest saturated fat intake have the lowest heart disease rates. France in not the only paradox [15]. A recent trial in Norway concluded, “clinical and public health recommendations regarding the ‘dangers’ of cholesterol should be revised” [16]. Heart disease is strongly associated with low HDL and high triglycerides. A low carbohydrate diet dramatically increases HDL and lowers triglyceride. Vegetable oils do, however, cause heart disease. A 1965 paper in the BMJ showed a high death rate from coronary heart disease with olive oil or corn oil and a low death rate with saturated fat [17].

An entertaining summary of the evidence can be found in a lecture given at the 2011 Ancestral Health Symposium about the Low Carb High Fat Diet, LCHF, followed by one third of the population of Sweden with good results [18].

The article in the BMJ is an excellent summary of the effect of a low fat diet. An achievement of only 1.6kg in weight loss demonstrates that we have been going in the wrong direction for 35 years. Advising increased consumption of animal fat and reduced carbohydrate to lose weight is probably too much of a paradigm shift for most people to accept. Having advised the opposite for a generation, many health professionals would need to overcome major cognitive dissonance if they were to adopt this change. Increasing numbers are altering their views and it is to be hoped that more will follow.

References:

1. The Diet Delusion ("Good Calories Bad Calories" in USA) by Gary Taubes

2. Why we get fat and what to do about it by Gary Taubes
3. http://vimeo.com/channels/418298/54861706, Talk by Gary Taubes
4. Big Fat Lies, is your government making you fat? By Hannah Sutter,http://www.bigfatlies.co.uk5. The Obesity Epidemic, What caused it? How can we stop it? by Zoe Harcombe
6. The Art and Science of Low Carbohydrate Living by Jeff S Volek PhD RD and Stephen D Phinney MD PhD
7. The A to Z Weight Loss Study: A Randomized Clinical Trial, JAMA. 2007;297:969-977
8. Wheat Belly by William Davis MD
9. http://uctv.tv/search-details.aspx?showID=16717, Sugar: the Bitter Truth
10. The Great Cholesterol Con by Malcolm Kendrick
11. Fat and Cholesterol are Good for You by Uffe Ravnskov
12. Ignore the Awkward, how cholesterol myths are kept alive by Uffe Ravnskov
13. The Great Cholesterol Myth by Jonny Bowden
14. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease, Am J Clin Nutr. 2010 Mar;91(3):535-46. Epub 2010 Jan 13.
15. http://www.drbriffa.com/2012/10/02/the-french-paradox-is-not-a-paradox, online study by Dr John Briffa
16. Is the use of cholesterol in mortality risk algorithms in clinical guidelines valid? Ten years prospective data from the Norwegian HUNT 2 study, Journal of Evaluation in Clinical PracticeVolume 18, Issue 1, Article first published online: 25 SEP 2011,http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2753.2011.01767.x/pdf17. Corn Oil in Treatment of Ischaemic Heart Disease, Rose et al, Brit. med. J., 1965, 1, 1531-1533
18. http://vimeo.com/29464690, LCHF diet

http://www.bmj.com/content/345/bmj.e7666/rr/619241