Set-Point Theory: Fact or Fiction?

It’s not uncommon to hear both lay persons and professionals matter-of-factly refer to the “starvation response” (also called metabolic adaptation) and “set-point theory” as if they were accepted facts. The supposition of these theories is that the body reacts to reduced energy intake, or weight loss, by lowering its basal metabolic rate in an attempt to maintain the current weight or return to a higher weight.

These theories however, have not survived sound scientific investigation, and those researchers who are familiar with this area of medical literature have known that for almost 20-years. Three comprehensive reviews of the literature in 1992, 1994, and 1995[i]^,[ii]^,[iii] all reached the same conclusions that:

• Dieting does not lead to an abnormal decrease in basal metabolic rate. A lower body weight does mean a lower basal metabolic rate, however it is not abnormal to the new reduced weight level.
• Dieting does not lead to an abnormal loss of lean body mass, or redistribution of body fat. When people gain weight part of their weight gain is lean body mass (muscle). When they lose weight they tend to lose the same ratio of fat and muscle that they originally gained.[iv]
• Dieting does not affect the future ease/difficulty of regaining/losing weight (at least from a physiological basis).

While those three reviews looked at the literature regarding people who were trying to lose weight, other research has looked at chronically undernourished populations expecting to find proof of metabolic adaptation, but the data simply do no support the theory.[v]^,[vi]^,[vii]

I've prepared a handout with a more detailed discussion of this topic for you: Set-point theory is not supported by the literature. You may also be interested in  Metabolism: Facts & Fiction, which is from my book The NEW Healthy Eating & Weight Management Guide.

Do you have a metabolism question that you want answered? Post your comment here!

Best,
-Dorene

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[i] Wing R, et al. Weight cycling in humans: a review of the literature. Ann Behav Med 1992;14:113-119.

[ii] NIH National Task Force on the Prevention and Treatment of Obesity. Weight Cycling. JAMA Oct. 19, 1994;272(15):1196-1202.

[iii] Muls E, et al. Is weight cycling detrimental to health? A review of the literature in humans. Intl J Obes 1995;19(3):46S-50S.

[iv] Wadden TA, et al. Effects of weight cycling on the resting energy expenditure and body composition of obese women. Int J Eat Disord 1996 Jan;19(1):5-12.

[v] Ferro-Luzzi A, et al. Basal metabolism of weight-stable chronically undernourished men and women: lack of metabolic adaptation and ethnic differences. Am J Clin Nutr 1997;66:1086-93.

[vi] Shetty PS. Chronic undernutrition and metabolic adaptation. Proceedings of the Nutrition Society. 1993;52:267-284.

[vii] Soares MJ, et al. Basal metabolic rates and metabolic efficiency in chronic undernourished. Euro J Clin Nutr. 1991;45:363-373.