Myths About Gaining Muscle and Burning Fat, Debunked

You've probably done a bit of research on how to build muscle and burn fat, but there's a good chance you ran into some myths along the way. For example, unqualified sources may have told you that muscle weighs more than fat, that you can't lose fat while gaining muscle, or that you should minimize your fat intake if you want to lose weight. Let's put those misconceptions to rest once and for all, so you can create a strong, healthy body without wasting time on BS.

Below, five commonly held (but false) beliefs about gaining muscle and burning fat, plus the real truth.

Myth: Muscle Can Turn Into Fat and Vice Versa

The two are entirely different tissues and can't magically morph into each other. Yes, when you're inactive, your muscle fibers will probably shrink while your fat cells will expand — and, when you're more active, the opposite is likely to occur — but that doesn't mean that the tissues are replacing one another.

Myth: Muscle Weighs More Than Fat

A pound of fat and a pound of muscle weight exactly the same. But — and this is where the confusion comes in — the volume of muscle is denser and more compact. "It would take four pounds of muscle to fill the space of one pound of fat," explains Michele Olson, Ph.D., senior clinical professor of exercise physiology at Huntingdon College in Montgomery, Alabama. That's why you might see results in the mirror without the number on the scale dropping.

Myth: Eating Fat Makes You Fat

Actually, the opposite is true — if you're eating good fats, that is. Healthy fats such as those found in nuts and fish, for example, will keep you fuller for longer and offer a bunch of important nutrients. Want proof? People eating a Mediterranean diet rich in olive oil and nuts lost more weight over a two-year period than those who stuck to a low-calorie diet, according to one study. Better yet, they were more likely to maintain that weight loss. (Here's more info on the benefits of a Mediterranean diet, plus a meal plan to help you get started.)

"These foods, as well as fish, avocado, and olives, contain omega-3 fats, omega-6 fats, and monounsaturated fats that are heart-healthy and fill you up so you don't overeat," explains Olson. Just watch your portion sizes, though: "Eating more calories than you use each day will lead to fat storage," says sports medicine physician Jordan Metzl, M.D.

Myth: You Can Spot-Reduce Fat

"When your body needs energy, it pulls from all of your fat cells, not just the areas you want to target," says Olson. In other words, to lose fat from any place, you have to lose fat from every place. Another truth: The first place where you gain fat typically is the last place you'll lose it. "When you put fat on easily in one area, it means your body is best able to store it there," notes Keith Baar, Ph.D., a professor at UC Davis School of Medicine.

Myth: You Can't Gain Muscle and Lose Fat at the Same Time

To shed fat, you have to burn more calories than you take in (what's sometimes called a caloric deficit). But when you do that, your body also burns some muscle. As a result, it's common to lose muscle mass as you lose weight.

The way to prevent this is to eat more protein, according to a study from the American Journal of Clinical Nutrition. Their study found that people who did so while on a high-intensity weight-training regimen were able to gain muscle mass while losing fat. "Getting enough protein provides your body with the amino acids it needs so that it doesn't have to break down muscle for them," says study author Stuart Phillips, Ph.D.