This study examined whether different methods of self-monitoring eating and exercise behaviors affect the process of self-monitoring and change in body weight in overweight adults. Forty-two subjects participated in a 16-week correspondence-based weight-loss intervention using a pretest-posttest randomized design. Dietary intake was prescribed at 1,200 to 1,500 kcal/day and <30% dietary fat. Physical activity was progressed to 200 minutes/week. Participants were randomly assigned to self-monitoring eating and physical activity behaviors using a traditional detailed method or transitioning to an abbreviated method. Transitioning to an abbreviated method returned significantly more diaries than using a traditional detailed method (P=0.04). Participants completing the study showed no significant difference in weight loss between the traditional detailed method (-7.5+/-5.3 kg) and the abbreviated method (-7.6+/-5.5 kg), with similar results for intention-to-treat analysis (detailed method -3.9+/-5.3 kg vs abbreviated method -4.3+/-5.8 kg). Weight loss was significantly associated with number of self-monitoring diaries completed (r=0.53, P<0.05). Findings suggest the self-monitoring process, rather than the detail of self-monitoring, is important for facilitating weight loss and change in eating and physical activity behaviors. Transitioning to a simplified approach to self-monitoring does not negatively affect short-term weight loss in overweight adults. These results may have implications for improving self-monitoring in overweight adults during periods of weight loss.