Body Weight Set Point Theory
Losing weight isn’t easy. Indeed, as many as 95% of dieters gain back unwanted weight and get trapped in endless cycles of yo-yo dieting. These results have led researchers to conclude that the human body may have a genetically determined set-point weight that is controlled by metabolic hormones and fat cell enzymes.
Metabolism Adjusts Itself
The set-point theory essentially argues that an individual’s metabolism will adjust itself to maintain a weight at which it is comfortable. Many studies have sought to evaluate if the set point can be altered, and some have gone as far as clinically monitoring the caloric intake and exercise of candidates – only to find that most overweight individuals cannot lose weight permanently.
Metabolic Changes After Dieting
A recent study published in the American Journal of Clinical Nutrition followed 24 overweight women for a four year period to evaluate metabolic changes after dieting. Metabolic rates decreased in the women when put on low-calorie diet. After losing an average of 30 pounds, the candidates stopped dieting only to see their metabolic rate increase – comparable to that of women who were never overweight. On average, the women returned to their initial overweight level by the four year follow-up evaluation; however, variations in their resting metabolic rate did not predict the amount of weight they regained.
Lead Author Dr. Roland Weinsier from the University of Alabama stated that, “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.”
Despite the authors’ conclusions, the weight loss candidates in the study gained back all lost weight. The true reason for the weight gain, according to the authors, was more likely due to the fact that calorie restriction was not maintained. In other words, failure to lose weight permanently is not due to a shift in metabolism – but an inability to continue on a well-designed weight loss program.