The Effects of High-Protein and High-Monounsaturated Fat Meals on Postprandial Lipids, Lipoprotein Particle Numbers, Cytokines, and Leptin Responses in Overweight/Obese Subjects

Background: Obesity is linked to dyslipidemia, proinflammatory state, and hyperleptinemia. The influence of high-protein (HP) versus high-monounsaturated fat (HMF) meals on postprandial lipids, lipoprotein particle numbers, cytokines, and leptin responses in overweight/obese (OW/O) subjects is unknown. Methods: Twenty-four OW/O participants consumed an HP (31.9% energy from protein) and HMF (35.2% fat and 20.7% monounsaturated fat) meal, of similar energy/carbohydrate content, in a random order. The outcome variables were assessed from blood samples collected in fasted and postprandial (3hr) states. Results: Repeated measures analysis found significant (P<0.05) meal condition by time interactions for triglycerides (TGs), very low-density lipoprotein particles (VLDLP), total high-density lipoprotein particles (T-HDLP), and the ratio of large-buoyant high-density lipoprotein 2b (LB-HDL2b) to T-HDLP, and meal effect on small-dense HDLP (SD-HDLP). Comparison of HP versus HMF condition showed significantly lower TG at 120min [geometric mean (95% confidence interval, CI): 148 (125-175) vs. 194 (164-230) mg/dL] and 180min [167 (138-203) vs. 230 (189-278) mg/dL] and VLDLP at 180min [70.0 (58.2-84.3) vs. 88.0 (73.1-106) nmol/L]. HP versus HMF condition showed significantly lower LB-HDL2b/T-HDLP at 180min [mean difference (95% CI): 0.021 (0.004-0.038)], and higher T-HDLP [671 (263-1079) nmol/L] and SD-HDLP [606 (292-920) nmol/L] at 120min. Area under the curve was significantly lower for TG and higher for T-HDLP, SD-HDLP, and small-dense LDL III (SD-LDL III) in the HP condition. Cytokines and leptin were not different between conditions. Conclusion: OW/O subjects had lower TG and VLDLP, but less favorable SD-LDL III, SD-HDLP, and LB-HDL2b/T-HDLP ratio responses to the HP versus HMF meals.