Ramadan fasting as a form of time-restricted eating during pregnancy and long-term health effects in offspring: a narrative systematic review

Abstract

Background Fasting and time-restricted eating (TRE) are popular practices that have health benefits, but may also carry a risk of harm. Little is known about the impact of TRE during pregnancy on the long-term health of offspring beyond the immediate post-natal period. Methods We conducted a systematic review and narrative synthesis of research on the health impact of time-restricted eating (TRE) during pregnancy and its potential long-term effects on offspring. We searched three electronic databases on 20 January 2023, and updated the search on 6 May 2024, combining search terms for pregnancy and fasting. Risk of bias was assessed using the ROBINS-E tool. We adhered to PRISMA and Synthesis Without Meta-analysis (SWiM) guidelines and the protocol was registered on PROSPERO (CRD42023387174). Results We identified 16 studies with data for 1,895,744 total participants mainly set in countries around or close to the equator, published between 2004 and 2023. All studies focused on fasting during Ramadan, a religious custom practiced among Muslims worldwide that consists of refraining from food and drink from sunrise to sunset, that represents the most studied form of TRE. Outcomes included effects on body size, cognitive performance, disability, respiratory health, child mortality and general health. Conclusions Results were consistent with the Developmental Origins of Health and Disease (DOHaD) model, showing offspring health risks associated with exposure to TRE during pregnancy. Body size was the most studied outcome and showed a strong correlation to exposure. The association between exposure and adverse effects appears to be stronger in low-income settings and becomes more apparent as the study sample grows older. Precautions should thus be taken by pregnant mothers when deciding whether to fast or not during their pregnancy. More research is needed to find a safe cut-off for time-restricted eating in different climates and socioeconomic settings. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-024-20367-2.