PHASE II: In the medical treatment protocol very severe obese patients with persistent GHD after LASGB will be inclosed. Starting from 15-day, GHD patients were re-evaluated by GHRH + Arginine test. After evaluation, the patients with persistent GHD will be randomized to be treated with Recombinant GH replacement therapy (Group A: Recombinant GH replacement therapy at the initial dose 0.15-0.30 mg/die; dose adjustment will be made according to IGF-I levels; Group B: no GH treatment). In both subgroups, the diet will arranged to fit an energy intake of 5.7 MJ/day (55% carbohydrate, 25% fat, 20% protein, 30 g fiber) and a moderate-intensity activity (brisk walking for 30-45 min/day) will be encouraged.