9 Hard Truths About Weight Loss

It’s not your imagination: When you try to lose weight, you’re fighting not only your cravings but also your own body. Weight loss decreases the hormone leptin, which signals to your brain that you’re full, and increases the hormone ghrelin, which stimulates hunger, according to research. This hormone imbalance continues long after you succeed at weight loss, making it even harder for you to keep the pounds off, according to the research.

Plus, if you cut too many calories too quickly, your metabolism will slow, says Sabrena Jo, senior director of science and research for the American Council on Exercise in San Diego. “If you cut calories drastically, and as a result you drop a lot of weight fairly quickly, it’s likely that you’re losing some muscle. Muscle is really the engine of metabolism, so that contributes to a lower metabolism,” she explains.

Eating too little also makes you more likely to rebound and go in the opposite direction by overeating because you were restricting yourself for so long. “We recommend doing things more moderately: Increasing physical activity and decreasing calories have been shown to be what works in the long run,” Jo says.