Today sees the publication of a study in the Journal of the American Medical Association in which the effectiveness of four diets were assessed over a year-long period [1]. Researchers at Stanford University School of Medicine ascribed women to eat either the Atkins’ diet (low carb), Zone diet (carb, protein and fat in the ratio of 40:30:30), LEARN diet (based on standard food pyramid) and the Ornish diet (low fat, high carb).
At the end of the year it was revealed that the most effective regime was the Atkins diet, with an average weight loss of 10.4 lbs. Average weight loss on the Zone, LEARN and Ornish diets were 3.5, 5.7, 4.8 lbs respectively. Note here that the effectiveness of the Atkins diet was approximately double that of higher carb diets (Ornish and LEARN).
But that’s not all, because the Atkins’ diet, compared to at least one of the other diets, brought about significant improvements in one or more health measurements such as blood triglyceride levels, ‘healthy’ high density lipoprotein (HDL) cholesterol levels and blood pressure. Taken as a whole, the Atkins’ diet beat the other ones hands down.
This result may come as a surprise to those who continue to tout the ‘benefits’ of a low fat diet. However, I can pretty sure these findings are precisely what individuals who use low and lower-carb diets in practice would expect. I, personally, have found lower-carb diets broadly beneficial not just in terms of weight loss, but in normalising physiology and biochemistry too.
Dr Chrisopher Gardner, one of the authors of this study, has speculated about how it might be that the Atkins’ diet might outperform other types of diets. He cited the fact that it was a simple message which people could easily understand and put intopratice. He also made reference to the fact that the diet is encourages water consumption and is rich in protein ” which, calorie for calorie, is more sating than either carbohydrate or fat.
All these seem like reasonable explanations for the apparent superiority of low-carb diets.
However, there is another fundamental reason why low-carb diets may be the best for us: they mirror the diet we are designed for.
Through the process of evolution, we have become best suited to the foods which we had access to. For the vast majority of our time on this planet this meant a diet based on meat, fish, vegetable matter, fruit, nuts and seeds. Analysis of primitive hunter-gatherer diets allows us a window into our evolutionary diet [2]. It turns out that compared to the primitive diet which we evolved on, the typical Western diet is significantly lower in protein and fat, while being much richer in carbohydrate.
Put another way, compared to the typical Western diet, the Atkins’ diet and other low-carb approaches are much more in keeping with the diet we, as a species, are best suited to from a genetic, metabolic, biochemical and physiological perspective. Let’s not be too surprised, then, that such as diet brings more benefits for health than higher-carb, lower-fat approaches traditionally touted as ‘healthy’.
References:
1. Gardner CD, et al. Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women: The A TO Z Weight Loss Study: A Randomized Trial JAMA. 2007;297:969-977.
2. Cordain L, et al. Plant-animal subsistence ratios and macronutrient energy estimations in worldwide hunter-gatherer diets. Am J Clin Nutr 2000;71:682-92
