This is a prospective study over 4 months, open, nonrandomized. 45 overweight or obese male subjects will complete 3 experimental sessions (0700-1400h) before and after 3 months of supervised physical training. During a first session, subjects will remain inactive and fasted (basal conditions). During the second session a standardized meal will be offered (postprandial response to a standardized meal). The third session will consist in the realization of an exercise bout (60min at 60%VO2 max) followed by a standardized meal (same meal that the previous day).