Benefits of aerobic conditioning and diet for overweight adults.

Excess bodyweight and obesity are one of the most common problems facing adult men and women of modern industrialised societies. Obesity is associated with alternations in glucose tolerance and lipoprotein profiles, which produces an increased risk for coronary heart disease. Starvation and low-calorie diets under 500 kcal/day reduce bodyweight and fat, but serious life-threatening problems can develop. For these reasons, moderate caloric restrictions between 1000 and 1500 kcal/day have been shown to produce the most successful long term weight loss. Exercise conditioning without caloric restrictions has been shown to reduce bodyweight, primarily fat weight, and increase lean bodyweight. However, this occurs only when the energy expenditure is greatly elevated and the exercise sessions are long in duration. Well controlled multiple-group studies indicate that exercise combined with caloric restriction is the best method for bodyweight and fat reduction. Including exercise in the diet regimen increases cardiorespiratory functional capacity, decreases cholesterol and triglyceride levels, and helps to retard the loss of lean muscle mass. The diet and exercise prescription which produces the best and safest results includes a diet of approximately 1200 kcal/day and a physical activity programme of at least 3 days/week, 20 to 30 minutes in duration, and at a minimum intensity of 60% of maximum heart rate.