The primary aim is to examine the effect of a high protein intake (from soy or whey protein) on weightmaintenance after weight loss in a group of predisposed (severe) obese persons. Furthermore, to examine short-term and long-term effect of a high protein intake on appetite regulation and diet induced thermogenese (DIT). Finally to examine the effect of calcium on weightmaintence, bloodlipid profilen, appetite regulation and DIT.