Nutritional and behavioral modification therapies of obesity: facts and fiction.

Current practice guidelines for management of overweight and obesity recommend a tripartite treatment - lifestyle modification program of diet, exercise, and behavior therapy for all persons with a body mass index of at least 30 (and those with body mass index 25 plus two weight-related comorbidities). Behavior therapy provides the structure that facilitates meeting goals for energy intake and expenditure. Lately, there has been a shift in focus from behavior change to cognitive change because it improves long-term results of lifestyle modification programs. Weight loss diets based on the amounts of individual macronutrients (high-protein diets, low-fat diets and low-carbohydrate diets, etc.) in the diet are not more effective than 'classical' low-calorie and balanced diets. An exception has been detected only in short-term diets with a low glycemic load. Also, epidemiological studies show that there is an inversely proportional relationship between body weight and Mediterranean diet. Cognitive behavioral therapy based on the Mediterranean diet has proven to be effective in clinical practice with regard to weight loss, body fat distribution, biochemical parameters, blood pressure and simplicity of following the diet.