Intended for healthcare professionals


Are some diets “mass murder”?

BMJ 2014; 349 doi: (Published 15 December 2014) Cite this as: BMJ 2014;349:g7654

Mass murder by diet

In his thoughtful commentary on “mass murder by diet” 1, Richard Smith implied that much of the blame for the harmful increase in carbohydrate intake was attributable to the promotion of the Cretan Mediterranean diet by Ancel Keys.

However, the Mediterranean diet put forward by Keys is not a low-fat diet at all; it is a diet high in beneficial fat (~40% of calories from fat, mainly olive oil)2, low in harmful animal fat and cholesterol, high in fruits, vegetables and legumes; and with its focus on whole grains, it is a low glycemic diet.

Saturated fat by itself is much less harmful than saturated fat when consumed in combination with cholesterol: dietary cholesterol has a permissive effect on the adverse effects of saturated fat on fasting lipids3. So analyzing saturated fat on its own is overly simplistic. This has been called the “bacon and egg effect”4: the bacon is much more harmful when consumed with egg yolk. (One large egg yolk contains more than the 200 mg daily intake of cholesterol recommended for patients at risk of cardiovascular events5.)

The biggest problem with much of what is written about diet is a misplaced focus on fasting lipids. Diet is about the post-prandial state, which occupies about 2/3 of the day6. Much of this misplaced focus results from the sustained propaganda campaign of the egg industry following their conviction for false advertising4. To understand this, please view the videos to which links are shown below.

The high carbohydrate intake that Smith rightly points out is 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 air2, by a committee trying to design a diet that would lower fasting cholesterol levels.

In the Israeli diet study7 comparing a Cretan Mediterranean diet with a low-fat diet and a low-carbohydrate diet, the Mediterranean diet was much better in diabetics than either a low-fat or a low-carb diet – there was a greater reduction of fasting blood glucose, insulin and insulin resistance on the Mediterranean diet. Furthermore, weight loss was better than on the low-fat diet, and identical, on the Mediterranean diet and low carbohydrate diet.

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

Video links:
Also see:

(1) Smith R. Are some diets "mass murder"? BMJ 2014; 349:g7654.
(2) Willett WC, Stampfer MJ. Rebuilding the food pyramid. Sci Am 2003; 288(1):64-71.
(3) Fielding CJ, Havel RJ, Todd KM, Yeo KE, Schloetter MC, Weinberg V et al. Effects of dietary cholesterol and fat saturation on plasma lipoproteins in an ethnically diverse population of healthy young men. J Clin Invest 1995; 95(2):611-618.
(4) Spence JD, Jenkins DJ, Davignon J. Dietary cholesterol and egg yolks: Not for patients at risk of vascular disease. Can J Cardiol 2010; 26(9):e336-e339.
(5) Reiner Z, Catapano AL, De BG, Graham I, Taskinen MR, Wiklund O et al. ESC/EAS Guidelines for the management of dyslipidaemias: the Task Force for the management of dyslipidaemias of the European Society of Cardiology (ESC) and the European Atherosclerosis Society (EAS). Eur Heart J 2011; 32(14):1769-1818.
(6) Spence JD. Fasting lipids: the carrot in the snowman. Can J Cardiol 2003; 19:890-892.
(7) Shai I, Schwarzfuchs D, Henkin Y, Shahar DR, Witkow S, Greenberg I et al. Weight loss with a low-carbohydrate, Mediterranean, or low-fat diet. N Engl J Med 2008; 359(3):229-241.

Competing interests: No competing interests

29 January 2015
J. David Spence
Professor of Neurology and Clinical Pharmacology and Director
Stroke Prevention & Atherosclerosis Research Centre
Robarts Research Institute, Western University, London, ON Canada N6G 2V2