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Letters Are some diets “mass murder”?

Are some diets “mass murder”? Mediterranean diet is not to blame for increased carbohydrate intake

BMJ 2015; 350 doi: (Published 11 February 2015) Cite this as: BMJ 2015;350:h613
  1. J David Spence, professor of neurology and clinical pharmacology and director1
  1. 1Stroke Prevention and Atherosclerosis Research Centre, Robarts Research Institute, Western University, London, ON, Canada N6G 2V2
  1. dspence{at}

Smith implied that much of the blame for the harmful increase in carbohydrate intake was attributable to Ancel Keys’s promotion of the Cretan Mediterranean diet.1

However, this diet is not a low fat one, being high in beneficial fat (~40% of calories from fat, mainly olive oil)2; low in harmful animal fat and cholesterol; and high in fruits, vegetables, and legumes. With its focus on wholegrains, it is a low glycaemic diet.

Saturated fat by itself is much less harmful than when consumed along with cholesterol: dietary cholesterol has a permissive effect on the adverse effects of saturated fat on fasting lipids.3 So it is overly simplistic to analyse saturated fat on its own. This has been called the “bacon and egg effect”—the bacon is much more harmful when consumed with egg yolk.4

Diet is not about fasting lipids but about the postprandial state. Much of the misplaced focus on fasting lipids results from the egg industry’s sustained propaganda campaign after its conviction for false advertising (see video links in the rapid response).

The high carbohydrate intake that Smith rightly points out as a problem resulted not from promotion of the Mediterranean diet, but from the endorsement by the American Heart Association of the low fat diet, pulled, as Willett and Stampfer said, from thin air by a committee trying to design a diet that would lower fasting cholesterol levels.2

A Mediterranean diet resulted in equal weight loss to a low carbohydrate one, with a greater reduction of fasting blood glucose, insulin, and insulin resistance than a low fat or a low carbohydrate diet.5

A low carbohydrate diet that is high in cholesterol and saturated fat would truly result in mass murder by diet.


Cite this as: BMJ 2015;350:h613



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