Is diet alone enough for sustained weight loss?
No. You’ll lose weight in the short term by slashing calories, but exercise is what keeps pounds off for good. Research shows that while dieting leads to short-term weight loss, the weight, like a boomerang, generally comes back. Adding exercise can change that picture.
Exercise burns calories, of course. It also builds muscle, which takes up less space than fat. The result: Your wardrobe fits better. Muscle tissue also requires more calories to sustain it than fat does. In other words, the more muscle tissue you have, the more calories you’ll burn at rest. That’s important because while diet alone may be effective at the outset, ultimately you’ll reach a plateau when your metabolism slows—and that’s when you’ll need to get moving.
A study conducted at the Washington University School of Medicine found that people who cut out 230 calories a day for a year and didn’t exercise, lost muscle mass, strength and aerobic capacity. People who exercised without cutting calories lost a similar amount of weight without sacrificing muscle mass.