Combo of exercise plus calorie cuts best for maintaining weight loss

According to a review of dozens of clinical trials, cutting down on calories and exercising are the best ways of shaking off that extra weight over the long-term.

The review analysed 80 weight-loss studies and found that programmes which focused on trimming calories with or without exercise were most effective at keeping the pounds off over a four year period.

The researchers say dramatic results were not seen but on average the participants in the studies shed 11 to 19 pounds at the most, then typically gained a little bit back over time.

The study authors, led by Marion J. Franz, a registered dietitian and health consultant with Minneapolis-based Nutrition Concepts, say that diet and exercise regime changes can work over time if people keep them up and have realistic expectations.

The studies analysed varied in their weight-loss tactics, in some, participants were given only general advice on cutting pounds, while in others, they received exercise advice or actual help with boosting their physical activity levels, but no help with diet.

In trials that focused on diet, some emphasized calorie reduction alone, and some used a combination of diet and exercise; in some participants were given meal replacements or weight-loss medications such as orlistat (Xenical) to enhance their diet changes.

Overall the team found diet-focused trials were most successful and advice-only and exercise-only studies produced "minimal" weight loss.

It was found that in those which used calorie-cutting alone and in those that added exercise, weight loss typically hit a plateau after six months, and participants on average gained a few pounds back.

The researchers say people should be prepared for their weight loss to taper off and the goal should be maintaining whatever success has been achieved.

Franz and her colleagues found that weight-loss medication appeared to help retaining the weight loss over the longer-term.

Franz and her colleagues say dieters often become frustrated because they think that if they maintain the low-calorie habit, the pounds should continue to fall off, but this does not appear to happen even when weight-loss interventions are continued.

Experts say exercise is important for cardiovascular health and general health and fitness and the key factors in weight loss are restricting the diet and promoting exercise.

They say however that it takes a lot of exercise to burn off excess calories - an average-weight person will burn about 100 calories walking a mile - so reducing calories is important in attempting to lose weight.

The weight-loss equation comes down to calories in versus calories out and it takes a deficit of 3,500 calories to lose a pound of fat; to lose just 1 pound a week a person will need to create an average 500-calorie deficit each day.

The study is published in the October 2007 issue of the Journal of the American Dietetic Association.