November 2, 2000 -- For many overweight people who lose weight, gaining it back is often a matter of time. Their cyclical weight gain-loss pattern leaves them feeling as though being "fat" is their destiny.
This cyclical weight gain-loss pattern has led some researchers to believe that the human body has a pre-set weight range and will automatically adjust its metabolic rate (the rate at which the body burns calories) to maintain a weight within its natural range. However, recent evidence published in the November issue of the American Journal of Clinical Nutrition (AJCN) provides a different perspective.
In a study of 24 overweight women, researchers found that a low-calorie weight-reducing diet slowed metabolism, but, when these women stopped dieting (after losing almost 30 pounds), their metabolic rate increased and was comparable to that of women who were never overweight. On average, the women returned to their initial overweight level by the 4-year follow-up evaluation; however, variations in their resting metabolic rate did not predict the amount of weight they regained.
Says lead author Dr. Roland L. Weinsier, "Confusion arises from the fact that our metabolic rate falls when we cut back on calories. This is nature's way of preventing starvation. But our results show that, after you lose weight and stop restricting calories, your metabolic rate returns to normal. Therefore, factors other than an abnormal metabolic rate must be responsible for the weight regain tendency."
Other research published in AJCN, Schoeller D, et al. 1997;66:551-556. http://www.ajcn.org/cgi/content/abstract/66/3/551 shows that increased activity after weight loss improves chances for maintaining a weight loss. More research is needed to understand the factors that lead to relapse after weight loss.
Source: Public Information Committee for the American Society for Nutritional Sciences and the American Society for Clinical Nutrition.
The American Society for Nutritional Sciences
The American Society for Clinical Nutrition
9650 Rockville Pike, Bethesda, Maryland 20814-3998
ASNS Phone: 301/530-7050
ASCN Phone: 301/530-7110, Fax: 301/571-1863
e-mail: secretar@ascn.faseb.org
Contact: Roland L. Weinsier, MD, DrPH
e-mail: weinsier@shrp.uab.edu
fax: 011-41-21-692-5595
Susan K. Fried, PhD
e-mail: sfried@rci.rutgers.edu
telephone: 732/932-9039
fax: 732/932-6837
Journal
American Journal of Clinical Nutrition