An umbrella review and meta-analysis of meta-analyses of the impact of Ramadan fasting on the metabolic syndrome components

Context Ramadan is a holy month of fasting, spiritual reflection, and worship for Muslims worldwide. However, the Ramadan fast - which involves abstaining from all food and drink, sunrise to sunset for 29 days-30 days annually - may also influence physical health outcomes, especially relating to the risk of metabolic syndrome.Objective The literature from the top of the pyramid of evidence was gathered and synthesized for this comprehensive umbrella review and meta-analysis of meta-analyses in order to provide an overall conclusion on the impact of Ramadan fasting with regard to metabolic syndrome components.Data Extraction Eleven systematic reviews and meta-analyses were included in the current umbrella review. Nine components, including waist circumference, body weight), high-density lipoprotein, low-density lipoprotein, total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure), and fasting blood plasma glucose were analyzed.Data Analysis The random-effects meta-analysis results revealed standard mean differences as follows: waist circumference -0.30 (95% confidence interval [CI] -0.33 to -0.27), body weight -0.34 (95% CI -0.39 to -0.29), high-density lipoprotein 0.20 (95% CI 0.10 to 0.30), low-density lipoprotein -0.10 (95% CI -0.13 to -0.07), total cholesterol -0.15 (95% CI -0.21 to -0.09), triglycerides -0.16 (95% CI -0.24 to -0.08), systolic blood pressure -0.20 (95% CI -0.23 to -0.17), diastolic blood pressure -0.20 (95% CI -0.22 to -0.18), fasting blood plasma glucose -0.10 (95% CI -0.12 to -0.08).Conclusion Ramadan fasting appears to benefit body weight, lipid profile, blood pressure, and fasting blood glucose levels. Therefore, engaging in fasting during Ramadan may contribute to weight reduction, decreased cardiovascular disease risk, improved blood pressure, and enhanced glycemic control. Nevertheless, the methodological quality of the included reviews ranged from low to critically low, necessitating cautious interpretation of conclusions drawn from these data.Systematic Review Registration Open Science Framework Identifier: DOI 10.17605/OSF.IO/9WVJZ.