1. Dietary Therapy

Eighty-six RCT articles evaluated the effectiveness of many different diets on weight loss: low-calorie diets (LCDs), very low-calorie diets (VLCDs), vegetarian, American Heart Association guidelines and the National Cholesterol Education Program's Step I diet with caloric restriction, and other low-fat regimens with varying combinations of macronutrients. The trials that included participants who were not overweight were rejected. Some trials were done in patient populations with diabetes, hypertension, or hyperlipidemia. Many of the trials do not mention whether concomitant physical activity programs were promoted, and many do not give information about the behavioral approaches that were used to deliver the diet or physical activity intervention. Approximately 60 percent of the trials are equal to or greater than 6 months in duration.