Effects of protein intake on energy‐restriction‐induced changes in lipid‐lipoprotein profile, glycemic control, resting energy expenditure, and appetite in overweight men

Abstract

PurposeTo assess the effects of dietary protein (pro) on diet‐induced changes in indices of metabolic health.MethodsFor 12 wk, overweight men (BMI 25.0–39.9 kg/m2), aged 24–75 y, consumed a 750 kcal/d energy deficit diet with 25% energy as fat, and either 15% pro (normal pro, NP, n = 21) and 60% CHO, or 25% pro (higher pro, HP, n = 22) and 50% CHO. The NP diet excluded striated tissue and eggs; the HP diet had 15% pro from eggs and 25% pro from lean pork. Pre and post‐study, fasting blood was taken; body composition, blood pressure (BP), and resting energy expenditure (REE) were measured; and daily appetite was assessed.ResultsReductions over time (p<0.05) in the NP and HP groups included: weight 10 and 9%; fat mass 21 and 20%; lean body mass (LBM) 5 and 3%; cholesterol 18 and 22%; HDL 9 and 9%; LDL 19 and 20%; triacylglycerol 30 and 42%; insulin 3.7 ± 1.4 and 5.4 ± 1.2 μU/mL; HOMA 0.9 ± 0.2 and 1.4 ± 0.2; systolic:diastolic BP 8:6 and 7:8%; and REE 260 ± 112 and 97 ± 78 kcal/d. Diet did not influence these responses, except ΔLBM was greater in NP vs. HP (time × group, p<0.05). ΔREE was predicted by ΔLBM (R2 = 0.21). Daily desire to eat ratings decreased in both groups, but hunger decreased in HP only.ConclusionOverweight men can successfully improve indices of metabolic health after weight loss when consuming a normal protein vegetarian or higher protein omnivorous diet.Support: Natl Pork Brd; Am Egg Brd‐Egg Nutr Ctr; Purdue Ingest Behav Res Ctr.Grant Funding Source: American Egg Board, National Pork Board