An Open Letter to Dr. Bruce Fife, Re: Coconut Oil

The group overfed MCT oils may have stored the excess energy less efficiently that the group receiving LCT oils, but they still did store this excess energy and gained weight from the beginning of the study. This does not support weight loss with MCT oils such as coconut oil. The article by Stubb (4) related only to calorie intake, and not to energy expenditure. Though participants in this 14-day study had a decreased their energy intake when consuming a diet containing MCT, they also had a decreased energy expenditure so, “Body Weight (BW) were not affected." Lastly, Van Wymelbeke (5) showed that participants eating a lunch immediately following a breakfast that contained MCT oils consumed fewer calories in that meal, but the amount of calories consumed during dinner was not affected. This one-day study did not measure energy expenditure nor MCT effects on body weight.

Simply, none of this data supports your claims that coconut oil helps thyroid function or weight loss. I remain underwhelmed, and with the exception that MCT oils may be healthier when substituted for (not added to) a diet containing excess carbohydrates or unhealthy trans-fats, it is my assessment that coconut oil is no better than “snake oil.”

Kenneth N. Woliner, M.D., A.B.F.P.
E-mail: knw6@cornell.edu

1. Jones PJH and St-Onge MP. (2002) Physiological effects of medium-chain triglycerides: potential agents in the prevention of obesity. Journal of Nutrition 132; 329-332.

2. Flatt, J. P., Ravussin, E., Acheson, K. J. & Jequier, E. (1985) Effects of dietary fat on postprandial substrate oxidation and on carbohydrate and fat balances. J. Clin. Investig. 76:1019-1024.

3. Hill, J. O., Peters, J. C., Yang, D., Sharp, T., Kaler, M., Abumrad, N. N. & Greene, H. L. (1989) Thermogenesis in humans during overfeeding with medium-chain triglycerides. Metabolism 38:641-648.

4. Stubbs, R. J. & Harbron, C. G. (1996) Covert manipulation of the ration of medium- to long-chain triglycerides in isoenergetically dense diets: effect on food intake in ad libitum feeding men. Int. J. Obes. 20:435-444.

5. Van Wymelbeke, V., Himaya, A., Louis-Sylvestre, J. & Fantino, M. (1998) Influence of medium-chain and long-chain triacylglycerols on the control of food intake in men. Am. J. Clin. Nutr. 68:226-234.

Reprinted by permission. Article originally published online.