Diet Versus Exercise in Weight Loss

A surprising new study in weight loss has recently come out of the US (Journal of Clinical Endocrinology & Metabolism (doi:10.1210/jc.2006-2184) contradicting some of the long held beliefs about the relationship between exercise and diet. It has been assumed for some time now that a combination of healthy eating and a regular fitness program is the best way to burn off those calories. It has also been assumed that building muscle mass will somehow increase metabolism and burn off even more calories.

This recent study looked at two groups. One group of dieters were put on a strict calory-controlled diet. A second group were given a diet which contained more calories but had a strict fitness regime that was designed to burn off the additional calories. Effectively both groups were faced with the same net reduction in available energy.

The results after this 6 month trial was a very similar weight-loss for the two group of dieters. Both groups lost around 10% of their body weight, 24% of their fat mass and 27% of their abdominal visceral fat. Visceral fat is found between the internal organs and is considered the most dangerous type of fat.

The findings of the study show that the important factor in losing weight is losing or limiting calories. Whether excess calories are removed from the body by exercising or the caloric intake is reduced by a sensible diet seems irrelevant. Weight and fat loss will occur equally if the calories are removed from the body or are never added in the first place.

The researchers have also done studies that suggest that building muscle can increase the body’s ability to loss weight. They found no evidence to support this long held belief. It appears that if anything, highly trained people become more efficient and so they burn fewer calories at rest.

The research team concluded that for overall health, an appropriate program of diet and exercise is still the best.