Effects of High-Quality Protein Supplementation on Lipid and Lipoprotein Profiles in Overweight and Obese Adults: A...

Overweight (OW) and obesity (OB) are prevalent chronic conditions commonly associated with abnormalities in lipid metabolism. Recent research suggests that high-quality proteins (HQPs), such as milk protein (MP), casein protein (CP), whey protein (WP), and soy protein (SP), may ameliorate lipid profiles.

This meta-analysis of randomized controlled trials (RCTs) assessed the impact of HQP supplementation on the lipid profiles in overweight and obese adults.

RCTs that fulfilled the inclusion criteria were identified by a comprehensive literature search in PubMed, Scopus, and the ISI Web of Science databases.

Data extracted included study characteristics, participant demographics, health status, sample size, intervention details (protein type, dose, and duration), cointerventions, and lipid outcomes.

Fixed- or random-effects models were used to calculate weighted mean differences (WMDs) and 95% CIs. Thirty-two RCTs (39 intervention arms) with 1357 participants (710 intervention, 647 control) were included. Meta-analysis showed that HQP supplementation significantly reduced low-density lipoprotein cholesterol (LDL-C) (WMD, -3.45 mg/dL; 95% CI, -5.77 to -1.13, P = .004) and total cholesterol (TC) (WMD, -5.70 mg/dL; 95% CI, -10.20 to -1.20; P = .013). No significant effects were observed for triglycerides (TG) (WMD, -4.25 mg/dL; 95% CI, -10.49 to 1.99; P = .182) or high-density lipoprotein cholesterol (HDL-C) (WMD, 0.33 mg/dL; 95% CI, -0.82 to 1.48; P = .574).

The findings of this study indicate that supplementation with HQPs was associated with reductions in LDL-C and TC; however, these effects were attenuated when high-risk-of-bias studies were excluded. Supplementation with HPQs did not affect TG and HDL-C. Additional trials with longer follow-up periods are necessary to confirm our results.