Purpose: To determine the effectiveness of elderly females aged 60-75 years following the Curves fitness and weight loss program on body composition, markers of health, and functional capacity. Methods: 55 senior aged overweight females (66 ± 5 years; 79 ± 11 kg) were randomly assigned to one of three groups: High Protein diet + Exercise (HP); High Carbohydrate diet + Exercise (NCHO); or Exercise only (E). Participants were instructed to follow their respective nutrition plans and complete a supervised 30 minute Curves circuit resistance-training program three times a week. The participants underwent an array of tests at 0, 10 and 14 weeks. An analysis of variance (ANOVA) for repeated measures was used to analyze the data. Results: Subjects in the HP experiencing significantly greater weight loss (HP -4.8 ± 3.2%, NCHO -3.0 ± 2.9%, E -1.1 ± 2.3%, p=0.001), fat mass (HP -10.2 ± 5.9%, NCHO -5.7 ± 4.0% and E -2.7 ± 3.9%, p=0.001), and percent body fat (HP -6.3 ± 3.5%, NCHO -3.8 ± 3.4%, and E only -2.2 ± 3.6%). Improvements were also noted in an appetite regulating hormones leptin (HP -42.1 ± 21.3%, NCHO 43.4 ± 56.1% and E .80 ± 35.1%, p=0.000). No significant changes were observed in fat free mass or resting energy expenditure. All groups experienced improvements in strength, muscular endurance, aerobic capacity, and a number of markers of health. Summary: The Curves exercise and weight loss program is effective in senior aged females in promoting weight loss and favorable body composition changes. The greatest effects were seen in the HP group.