If you want to lose weight, following a low-carb diet could yield better results than following a low-fat diet, according to research out of Tulane University, published in the Annals of Internal Medicine journal. The study followed 148 obese patients for a year who were following either a low-fat diet, where less than 30 percent of daily calories came from fat or a low-carb diet, where they consumed less than 40 grams of digestible carbs per day. After a year, the low-carb dieters lost nearly eight pounds more than the low-fat group, and also improved their cholesterol numbers.

But the truth is, carbs aren’t all good or all bad. Some promote health while others—when eaten often and in large quantities—can pile on the pounds and increase your risk for disease.

Sugar-laden carbohydrates such as doughnuts, sodas and other highly processed foods may indeed kick-start weight gain and interfere with your ability to reach your physique goals. But sources such as fruits, oatmeal, vegetables, whole-grain breads and other varieties of intact carbs do just the opposite when eaten in moderation: They promote good health.

Follow these cardinal carb rules, and you’ll burn more fat and sculpt more muscle in no time.