The Journal of Nutrition Nutrition and Disease A Moderate-Protein Diet Produces Sustained Weight Loss and Long-Term Changes in

Diets with increased protein and reduced carbohydrates (PRO) are effective for weight loss, but the long-term effect on maintenance is unknown. This study compared changes in body weight and composition and blood lipids after short-term weight loss (4 mo) followed by weight maintenance (8 mo) using moderate PRO or conventional high-carbohydrate (CHO) diets. Participants (age 45.4 6 1.2 y; BMI 32.6 6 0.8 kg/m2; n 130) were randomized to 2 energy-restricted diets (2500 kcal/d or 22093 kJ/d): PRO with 1.6 gkg21d21 protein and,170 g/d carbohydrates or CHO with 0.8 gkg21d21 protein,.220 g/d carbohydrates. At 4 mo, the PRO group had lost 22 % more fat mass (FM) (25.66 0.4 kg) than the CHO group (24.66 0.3 kg) but weight loss did not differ between groups (28.26 0.5 kg vs.27.06 0.5 kg; P 0.10). At 12 mo, the PRO group had more participants complete the study (64 vs. 45%, P, 0.05) with greater improvement in body composition; however, weight loss did not differ between groups (210.4 6 1.2 kg vs. 28.4 6 0.9 kg; P 0.18). Using a compliance criterion of participants attaining.10 % weight loss, the PRO group had more participants (31 vs. 21%) lose more weight (216.56 1.5 vs.212.36 0.9 kg; P, 0.01) and FM (211.76 1.0 vs.27.96 0.7 kg; P, 0.01) than the CHO group. The CHO diet reduced serum cholesterol and LDL cholesterol compared with PRO (P, 0.01) at 4 mo, but the effect did not remain at 12 mo. PRO had sustained favorable effects on serum triacylglycerol (TAG), HDL cholesterol (HDL-C), and TAG:HDL-C compared with CHO at 4 and 12 mo (P, 0.01). The PRO diet was more effective for FM loss and body composition improvement during initial weight loss and long-term maintenance and produced sustained reductions in TAG and increases in HDL-C compared with the CHO diet. J. Nutr. 139: 1–8, 2009