An emphasis on increasing self-regulation is an alternate to nutrition education, which has had poor results in the behavioral treatment of obesity. Although appropriately designed weight-loss treatments may enhance one’s self-regulatory ability to control eating, whether improvements are moderated by psychosocial factors such as initial self-regulatory skills use, self-efficacy to control eating, and mood is unknown. Severely obese women (BMI 35-50 kg·m^-2) were randomized into 26-week treatments of exercise supported by cognitive-behavioral methods paired with either nutrition education (n = 114) or cognitive-behavioral methods applied to controlled eating (n = 121). Improvement in self-regulation for controlled eating was 36.9% greater (p < 0.01) for the group incorporating cognitive-behavioral methods for controlled eating. Change in self-regulation was significantly associated with self-regulation at baseline (β = -0.33). Both mood and self-efficacy for controlled eating significantly moderated this relationship. Increased self-regulation was associated with both increases in fruit and vegetable consumption and fruit and vegetable intake at treatment end. The present findings increase our understanding of psychosocial variables associated with increased self-regulatory skills usage and improvements in eating that, after replication, may be used to improve the effects of behavioral weight-loss treatments.