In one of the few studies done under controlled conditions, the Journal of Clinical Endocrinology & Metabolism reports that cutting food portions reduces fat, and that exercise doesn't help burn any more calories, than cutting portions.
Tests on overweight people show that a calorie is just a calorie, whether lost by dieting or by running, they said.
They found there is no way to selectively lose belly fat, for instance, or trim thighs. And their carefully controlled study added to evidence that adding muscle mass does not somehow boost metabolism and help dieters take off even more weight.
"It's all about the calories," said Dr. Eric Ravussin of the Pennington Biomedical Research Center, part of Louisiana State University in Baton Rouge.
His team found some small suggestion that cutting 25 percent of calories by either diet or diet and exercise might extend life.So, forget all those diet claims. It's doesn't cost a thing to cut your own portions and live much healthier...and longer.