Answered by Louise Jarvis on Monday, June 1, 2009
Yo-yo dieters will be relieved to hear that the National Institutes of Health (NIH) found "weight cycling" (the repeated losing and regaining of weight) does not affect one's metabolic rate (the rate at which your body burns calories for energy). Cycling, says the NIH, "should not affect the success of future weight loss efforts," whether you're losing and gaining 10 pounds or 50. Dieters typically lose and regain about 75 percent fat and 25 percent muscle, says Gary Foster, Ph.D., clinical director of the Weight and Eating Disorders Program at the University of Pennsylvania School of Medicine. Because muscle demands more calories to function than fat—one pound of muscle burns about 15 calories a day—dieters fear muscle loss will slow metabolism and therefore the rate of weight loss. The truth is, says Dr. Foster, "most people don't gain or lose a significant amount of muscle while dieting"—but training during your diet is a surefire way to tip the scales in your favor: The single greatest predictor of long-term weight loss is sustainable, consistent exercise. Aim to complete four 40-minute cardio sessions plus two 20-minute resistance training sessions a week. Yet another reason to do your gymamerica.com workout.