The study is a parallel RCT with a weight loss (WL) period (8 weeks on very low calorie diet) and a weightmaintence (WM) period (24 weeks daily intake of supplement). 200 overweight/obese subjects will be enrolled into the study and randomized to placebo (maltodextrin), soy protein, whey protein or calcium enriched whey protein supplement. At baseline (week 0), after the WL period (week 8) and after WM period (week 24) body weight and composition will be measured and blood samples will be collected. Meal test will be performed at week 0 and 24 (examining both appetite regulation and DIT). Urine and feces will be collected three times during the study. Subjects will receive dietary counseling (in groups) regularly during the study and body weight will be measured at each visit.