In a recent study of 52 obese men with an average body mass index (BMI) of 31, Canadian researchers demonstrated the power of exercise as a weight loss tool.

One group of men dieted, consuming 700 calories per day less than they needed to maintain their weight. Another group walked or jogged on a treadmill at 80 percent of heart rate maximum for about an hour each day, long enough to burn off 700 calories.

After three months, both dieters and exercisers lost the same amount of weight - about 16.5 lbs, or eight percent of their body weight.

Exercisers, however, lost more abdominal fat (4.2 lbs) than dieters (3.3 lbs).

Exercisers also did not lose muscle mass the way dieters did, and got the added benefit of improved cardiovascular fitness.

A third study group kept their weight stable by burning off 700 calories per day with exercise, but making up for it with an extra 700 calories of food.

Although these men did not lose weight, they did lose visceral abdominal fat, which may reduce the risk of cardiovascular disease and diabetes.