Effect of Ramadan Fasting on Blood Lipid Profile Among Populations in the South Asia Region: A Systematic Review and Meta-Analysis.

Ramadan fasting involves abstinence from food and drink during daylight hours for 30 consecutive days. While beneficial effects of Ramadan intermittent fasting (RIF) on cardiometabolic risk factors have been suggested, findings related to blood lipid profiles remain inconsistent, particularly among South Asians, who are highly predisposed to dyslipidemia and cardiovascular disease. This systematic review and meta-analysis aimed to evaluate the effects of RIF on lipid profiles among selected South Asian populations from India, Pakistan, Bangladesh, Nepal, and Sri Lanka. These countries were selected due to their disproportionately higher cardiovascular risk burden, shared dietary practices, and availability of comparable studies. A comprehensive literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines across PubMed, Embase, Scopus, Web of Science, and Google Scholar up to March 2025, retrieving 2,430 records; 10 studies (n=432) comprising randomized controlled trials and observational cohort studies in adult populations (healthy and those with controlled metabolic conditions) met all inclusion criteria. Meta-analysis using random-effects models demonstrated significant lipid improvements post-Ramadan, including increased high-density lipoprotein cholesterol (HDL-C) (Z=2.50, p=0.01), decreased low-density lipoprotein cholesterol (LDL-C) (Z=2.19, p=0.03), and decreased total cholesterol (TC) (Z=2.11, p=0.03). No statistically significant change was observed for triglycerides (TG) (Z=0.27, p=0.78). Substantial heterogeneity (I > 80%) was observed for all lipid parameters, likely due to methodological differences, varied dietary adherence, baseline health status, and cultural dietary habits. Variability was explored via sensitivity analyses and qualitative assessment of individual study characteristics. Unlike other lipids, TG responses varied considerably, potentially attributable to increased consumption of fried and fatty foods during the non-fasting hours, reduced lipoprotein lipase activity, and increased mobilization of free fatty acids. These findings indicate that RIF can confer cardiovascular benefits through improved HDL-C, LDL-C, and TC, though TG outcomes remain influenced by dietary and metabolic factors. Future research should incorporate structured dietary guidance during Ramadan and investigate genetic, gender-specific, and lifestyle determinants to reduce heterogeneity and optimize cardiovascular outcomes associated with RIF.