This proposed investigation is a randomized, equivalency trial to test the effectiveness of a phone based weight management program compared to a traditional face-to-face clinic program for weight loss and weight maintenance. It is expected that at 6 months participants in the phone and clinic groups will show equivalent weight loss and that weight loss will be at least 10% lower than baseline. During weight maintenance some weight gain may occur. However, we expect both phone and clinic groups to gain a similar amount of weight and that weight for both groups at 18 months will be significantly less than baseline weights.