The incidence of overweight and obesity is a serious public health crisis in the U.S. and other developed countries. Current estimates show that approximately 65 percent of U.S. adults are overweight (defined as a body mass [BMI] index between 25 and 29.9) or obese (BMI of 30 or more). Obesity is a major causative factor in a number of conditions including heart disease, diabetes, hypertension, stroke, and even certain types of cancer. Clearly the most successful weight-loss strategy is to reduce overall caloric intake, while increasing caloric expenditure through exercise.
The 2005 United States Department of Agriculture (USDA) Dietary Guidelines for Americans put forth strong recommendations on weight loss and physical activity. "Making moderate physical activity a part of an adult's daily routine for at least 30 minutes per day promotes fitness and reduces the risk of chronic health conditions such as obesity, hypertension, diabetes, and coronary artery disease,"