Background: There is growing attention to the underrepresentation of men in studies of weight loss and weight loss maintenance (e.g., 20% in the National Weight Control Registry). Therefore, the purpose of this study was to explore gender differences within a weight loss maintenance trial prior to entering the program and during and after treatment. Methods: Data for this analysis come from the Keep It Off randomized trial which tested the effect of an interactive phone-based weight loss maintenance intervention over 24 months for participants who had previously lost a minimum of 10% of their body weight in the prior year. Participants (N=419, 18.4%male, age 47.0±10.8, BMI 28.4±5.0) were asked prior to randomization how they initially achieved their weight loss. At baseline, 12 months, and 24 months, participants reported their current eating patterns (e.g., meals eaten over the prior week), dietary intake (NCI’s Diet History Questionnaire), and physical activity (Paffenbarger Physical Activity Questionnaire). Results: At study entry, women had lost moreweight than men (16.4±5.4 vs. 15.0±4.9%, p=0.03). A greater percentage of women (55.9%) than men (24.7%, p‹0.001) used an organized weight loss program as their method for initial weight loss. Women were more likely to report a weight loss motivated by improving issues related to personal esteem than men (51.2 vs. 35.1%, p=0.01) but reported similar health motivators (68.2 vs. 74.0%, p = 0.31). There were few differences in eating patterns at baseline with similar percentages of men and women reporting eating breakfast (62.1%), lunch (61.8%), and dinner daily (72.5%, p’s›0.05). Men were more likely than women to report ever eating food purchased at a convenience store (22.1% vs. 13.1%, p = 0.05). Similar resultswere observed at 12 and 24 months. Calorie intake was higher in men at baseline, 12, and 24 months while daily selfweighing and physical activity was similar between men and women at each time point. Conclusions: Although men are underrepresented in studies of weight maintenance, it does not appear that they use different behaviors to achieve weight loss maintenance than women. To better involve men in weight loss maintenance interventions, program developers should consider changing the messaging or program format to appeal more to men rather than changing treatment program content.