Methods: In this randomized, treatment controlled clinical trial, 146 obese, sedentary adults with impaired glucose tolerance will be assigned to Low carb diet (LCHbd) or an isocaloric diet with a high carb, high protein breakfast (HCPbd),1400 kcal for women and 1600 kcal for men. LCHbd breakfast will provide 300 kcal with carb: protein: fat of 13:40:48. HCPbd breakfast will provide 600 kcal with 50:20:30. From baseline until week 16 participants will take part in a supervised weight loss diet, followed until week 32 by a maintenance period. Anthropometric measures, OGTT for glucose and insulin, VAS-measured hunger and satiety and Food Craving Inventory Analysis will be performed at baseline, week 16 and week 32.