Middle-aged and young-old obese subjects will be enrolled at a specialised nutrition clinic. Subjects will be on a maintenance weight management program including lifestyle advice and diet based on the principles of the Modern Mediterranean Diet Pyramid (variety in food choices, seasonality and spices to flavor dishes). The diet is modified to avoid high caloric food and distributed in 3 main meals and 2 healthy snacks during the day to provide a caloric intake of 28-30 kcal/die/kg body weight and macronutrient breakdown as recommended by INRAN (http://www.inran.it/) (Protein 15%, Fat < 30%, carbohydrates 55/60% of which soluble 10-12 % and fiber 30 g die).