Anyone who has been on a diet knows the hard work of counting calories, fat and carbs - and sometimes the sacrificing of flavor for function as we eat whole bran and dry fat-free cardboard food. The worst part about dieting is that nearly all people who manage to lose weight don’t succeed in keeping it off - in most cases the weight returns and sometimes dieters regain more than they lost.

A study at UCLA found that only a small minority of dieters consistently kept the weight off after losing it. Researchers also say that the yo-yo of losing and gaining weight may be linked to an increased risk of cardiovascular disease, stroke, diabetes and altered immune function. The researchers concluded that many people would have been better off had they not gone on a diet at all.

Although a number of diets will work in the short term, researchers found that the largest predictor of future weight gain was whether or not the individual had recently lost weight on a diet.

According to Traci Mann, UCLA associate professor of psychology and lead author of the study, the evidence suggests that exercise, not dieting, may be the key to maintaining weight loss.

“Eating in moderation is a good idea for everybody, and so is regular exercise,” Mann said. “That is not what we looked at in this study. Exercise may well be the key factor leading to sustained weight loss. Studies consistently find that people who reported the most exercise also had the most weight loss.”

Dieting Does Not Work, UCLA Researchers Report