One cup of grapes: 60 calories. Three Oreos: 160 calories. One half-cup cereal: 220 calories. Sound familiar? You’ve probably tried counting calories to lose weight—and maybe it even worked. At first, anyway. Over time, though, those pounds climbed back on because of one important point: Calorie counting doesn’t work, says Jonathan Bailor, author of the new book, The Calorie Myth. In fact, it’s one of the worst strategies you can use when you want to lose weight.

"I used to count calories, too—but I’d try to eat 6,000 a day because I wanted to bulk up," says Bailor. A personal trainer at the time, Bailor’s clients were mainly women over 35 who wanted to slim down, and his advice to them was the same as what he gave himself: Count calories, but stick to 1,200 a day to lose weight. The results weren’t good for anyone. "I was getting sick and fat, and these women, even on such restricted diets, were also getting sick and fat. I stopped training because I realized that advising them to count calories was actually hurting them."

Bailor says he noticed a disconnect between research and what experts—including him—were teaching others about counting calories, which led to his book. We talked to Bailor about five popular calorie myths you should forget you ever heard.