Purpose: The dietary habits contributing to weight loss maintenance are not sufficiently understood. We studied weight loss maintainers in comparison with regainers, to identify the differentiating behaviors. Methods: The MedWeight study is a Greek registry of weight loss maintainers and regainers. Participants had intentionally lost ≥10 % of their weight and either had maintained this loss for over a year, or had regained weight. Questionnaires on demographics and lifestyle habits were completed online. Dietary assessment was carried out by two telephone 24-h recalls. Results: Present analysis focused on 361 participants (32 years old, 39 % men): 264 maintainers and 97 regainers. Energy and macronutrient intake did not differ by maintenance status (1770 ± 651 kcal in maintainers vs. 1845 ± 678 kcal in regainers, p = 0.338), although protein intake per kg of body weight was higher in maintainers (1.02 ± 0.39 vs. 0.83 ± 0.28 g/kg in regainers, p < 0.001). Physical activity energy expenditure was greater for maintainers in men (by 1380 kcal per week, p = 0.016), but not women. Salty snacks, alcohol and regular soda were more frequently consumed by men regainers. Principal component analysis identified a healthy dietary pattern featuring mainly unprocessed cereal, fruit, vegetables, olive oil and low-fat dairy. Male maintainers were 4.6 times more likely to follow this healthy pattern compared to regainers (OR 4.6, 95 % CI 2.0–11.0). No similar finding was revealed in women. Other characteristics of maintainers but not of regainers were: involvement in meal preparation and eating at home for men, and a higher eating frequency and slower eating rate for women. Conclusions: Men maintaining weight loss were much more likely to adhere to a healthy eating pattern. Eating at home, involvement in meal preparation, higher eating frequency and slower eating rate were also associated with maintenance. These lifestyle habits of successful maintainers provide target behaviors to improve obesity treatment.