Effect of Macronutrient Composition on 12-Month Weight Loss in Overweight Women

Abstract

0697 PURPOSE: To examine the relationship between macronutrient composition (dietary carbohydrate and protein) on 12-month weight loss in overweight women. METHODS: Data from 164 women (age = 37.62 ± 5.42 years; body mass index = 32.53 ± 4.09 kg/m2) who completed a 12-month behavioral weight loss program were analyzed. Participants were prescribed a reduced energy (1,200 to 1,500 kcal/d) and dietary fat (20 to 30%) diet and 150 to 300 min/wk of moderate to vigorous intensity exercise. Subjects attended group behavioral sessions and received intervention telephone calls throughout the study. Total energy and macronutrient content were measured using the Block Food Frequency Questionnaire with physical activity assessed using a 7-day physical activity recall (7-day PAR). Participants were separated into higher and lower intakes of percent carbohydrate and protein. Participants in the highest tertile of carbohydrate intake (>56% intake) and lowest tertile of protein intake (<16% intake) were classified as HC/LP (N = 25). Participants in the lowest tertile of carbohydrate intake (<50% intake) and highest tertile of protein intake (>17% intake) were classified as LC/HP (N = 26). RESULTS: The HC/LP group reported 60.82 ± 3.02 % carbohydrate intake and 13.27 ± 1.31% protein intake. The LC/HP group reported 44.61 ± 6.62 % carbohydrate intake and 20.32 ± 2.63% protein intake. Weight loss at 12-months was significantly greater in HC/LP (10.38 ± 7.74 kg) compared to LC/HP (6.16 ± 6.06 kg) (P <0.04). There was no statistical difference in total energy intake between the HC/LP (1305.80 ± 604.44 kcal/d) and LC/HP (1437.23 ± 583.65 kcal/d) groups. Physical activity did not differ statistically between HC/LP (220.83 ± 100.25 min/wk) and LC/HP (160.00 ± 116.08 min/wk). CONCLUSION: Within the confines of this study, it appears that 12-month weight loss was enhanced in participants consuming a higher carbohydrate and lower protein diet compared to those consuming a lower carbohydrate and higher protein diet. Additional research is necessary to understand the impact of macronutrient composition on long-term weight loss in overweight and obese individuals. Supported by National Institutes of Health (HL64991)