Studies show exercise may not be enough for weight loss

Source: The New York Times, PLOS Online Journal, August 2012 

Two recent studies have attempted to rectify the winded debate surrounding why many can't lose weight with a regular workout regimen.

Anthropologists leading one of the studies recruited members of the Hadza tribe in Tanzania who survive primarily by hunting and gathering. Equipping them with GPS units and water containing tracers, the scientists were able to record the tribe people’s metabolic rate and energy expenditure. They then compared these numbers to those of the average Western person. They found that, though the members of the Hadza tribe were far more active, their metabolic rate was about the same as an average Westerner. The study concluded that a lower calorie diet will yield better weight-loss results than exercising regularly. Active lifestyles may not protect against obesity if diets change to promote increased caloric consumption.

A second study delved deeper into the subject, claiming that exercise does not speed up one's metabolism and may even slow it down. The study claimed that even the most in-depth studies that monitored exercise, food intake and metabolic rates found that many volunteers’ basal metabolic rates dropped as they lost weight, even with regular exercise. The new study produced a new weight-loss formula that takes into account a dropping metabolic rate. Working with a group of volunteers, researchers are now able to provide a more accurate prediction of how much weight a volunteer can expect to lose.