The purpose of the study was to investigate the relationships between changes in flexible vs. rigid restraints of eating during weight management, as well as how changes in the cognitive restraint of eating were related to psychological well-being and flexibility. The data includes information on 49 overweight persons who participated in a weight loss and maintenance (WLM) intervention and a follow-up assessment after 8-9 months. An increase in flexible cognitive restraint during the weight loss intervention was related to better weight loss maintenance and well-being. The more flexible restraint increased during the WLM intervention, the more psychological distress decreased. Moreover, larger reduction of rigid restraint during the follow-up period (between the WLM intervention and the follow-up assessment) was related to a better maintenance of improved psychological well-being at the follow-up endpoint. These results suggest that increasing flexible control while reducing rigid control of eating after an active weight loss phase improves success in weight management and the psychological well-being of weight losers.