A qualified healthcare provider should be consulted before making decisions about diet programs, therapies, and/or health conditions.

Truby et al. conducted a six month multi-center controlled trial studying weight loss and body fat in overweight and obese adult subjects who were otherwise healthy. Participants were assigned to one of four diets: The British Weight Watchers® pure points program, Dr. Atkins' new diet revolution®, the Slim-Fast plan®, and Rosemary Conley's eat yourself slim diet and fitness plan. Regardless of the program followed, all participants experienced weight and body fat loss. The authors concluded that all four diets may be clinically useful for weight loss over a six month period of time for individuals who follow the guidelines of each diet.

Dansinger et al. conducted a single center randomized trial to access the success and adherence rates of overweight or obese adults in achieving weight loss and reducing risk of heart disease. Participants were assigned to follow the Weight Watchers®, Atkins®, Ornish, or Zone® diets. All groups saw modest reductions in weight loss and body fat, although adherence to treatment plans was low. The authors did not specify if the weight loss occurred due to the diets or other factors.