The Calorie "Window" for Women

Power Eating author Susan M. Kleiner, who pens the Ask An Expert column on OxygenMag.com, talks about the caloric balance needed to lose fat AND maintain lean muscle.

Q: I have a question regarding the paradox of fat loss and metabolism. It is my understanding that not eating slows your metabolism and puts your body into “starvation mode,” making it difficult to lose weight. But we need to eat fewer calories to lose weight. Where is the balance? When do you start losing fat?

A: Research by Dan Benardot, Ph.D., at Georgia State University has shown there is a 300-calorie “window” for women below their energy needs where they maintain metabolic rate and lose fat efficiently. As you go below that window, your metabolic rate will begin to slow down and despite eating fewer calories you will lose less weight. In his research study, Benardot showed that gymnasts eating 500 calories below their estimated requirement lost less weight and fat compared to gymnasts on the same team doing the same exercise who ate only 300 calories below their needs. So eating less does not get you greater weight loss. I have found with my clients that staying within the 300 calorie “window” is a very efficient and effective way to lose body fat and maintain the lean muscle that keeps your metabolic rate high.