The Combined Effect of Aerobic Training and Vegetarian Diet on Lipid Profile in Adults: A Systematic Review and Meta-Analysis

Introduction: Exercise training and vegetarian diets have been accepted as suitable and non-pharmacological methods for improving lifestyle and mitigating obesity, and related metabolic diseases. The aim of this study was to investigate the combined effect of aerobic training and vegetarian diet on lipid profile of adults. Material & Methods: A comprehensive search of English and Persian articles was conducted on databases including PubMed, Web of Science, Scopus, SID, Magiran, and Google Scholar, up to February 2023. Meta-analyses were conducted to compare the effects of aerobic exercise and vegetarian diet on body weight, as well as lipid profile parameters (low-density lipoprotein, high-density lipoprotein, triglyceride and total cholesterol). Standardized mean differences (SMD), weighted mean differences (WMD), and 95% confidence interval (CI) were calculated using a random effect model. Additionally, the I2 test was assessed the heterogeneity, and Funnel plots and Egger tests at a (significance level: 0.1) were employed to identify publication bias. Results: The meta-analysis, comprising 36 studies with 10,795 adults, showed that aerobic exercise and vegetarian diet significantly decreased body weight [WMD=-4.5, (CI: -5.68 to -3.31), p=0.001], low-density lipoprotein [SMD=-0.35, (CI: -0.44 to -0.26), p=0.001], high-density lipoprotein [SMD=-0.16, (CI: -0.29 to -0.03), p=0.01], triglyceride [SMD=-0.11, (CI: -0.17 to -0.05), p=0.001], and total cholesterol [SMD=-0.44, (CI: -0.57 to -0.32), p=0.001]. Data analysis utilized Comperhensive Meta-analysis software version 2. Discussion & Conclusion: The findings of the present meta-analysis showed the important role of exercise and vegetarian diet in improving lipid profiles. Therefore, aerobic exercise and vegetarian diet are recommended as non-pharmacogloical strategies for reducing body weight and improving lipid profiles in adults.