A randomized, non-blinded, controlled clinical trial using a parallel design of a hypocaloric, low fat (\<30% energy from fat) diet with or without 2 oz of almonds over 18 months. Interim analyses will be conducted at 3, 6, 9 and 12 months. The study will be divided into 3 phases. Phase 1 (months 0-6) will be an active, intensive weight loss phase. During phase 1, all subjects will meet once a week in the evening for 1.5 hours. Phase 2 (months 6-12) will be a less intensive weight loss phase. During phase 2 groups will meet every other week in the evening for 1.5 hours. The last phase will be the weight maintenance phase or phase 3 (months 12-18).