Dear doctors: I heard that when you go on a diet and reduce your caloric intake many times over, your body begins to use muscles for energy. Is that really true? How can you lose weight and not lose muscle?
Dear Reader: Discussions about losing weight usually focus on pounds, as in “I want to lose 10 pounds”. The important follow-up question here is: pounds of what? Exercise with a hefty set of tennis and the scale will show you lost a few pounds of water immediately. You will get it right back with your next drink. (A quart of water weighs 2 pounds in case you were curious.)
Diets that involve drastic calorie reductions do result in weight loss, but participants burn not only fat, but also significant amounts of muscle mass. This is a bad idea because we rely on our muscles for both strength and endurance. Muscle tissue also plays an important role in resting metabolic rate.
The answer to the “pound of what?” Weight loss question is of course fat. When we set a weight loss goal, the goal is to lose fat. Or, to make it more useful, we want to achieve healthier lean tissue to fat ratios. Achieving and maintaining a healthy weight has many benefits, including reducing the risk of diabetes, high blood pressure, coronary artery disease, depression, and even certain types of cancer. And while it is tempting to try some of the more extreme low-carb and high-fat diets that are popular today and promise quick and painless weight loss, we believe that a moderate approach leads to better, more sustainable results.