Recent Evidence on the Impact of Ramadan Diurnal Intermittent Fasting, Mealtime, and Circadian Rhythm on Cardiometabolic Risk: A Review

Ahmed S Bahammam,Aljohara S Almeneessier

doi:10.3389/fnut.2020.00028

Abstract

In this article, we reviewed recent data that examined the relationship of circadian rhythm, mealtime, and intermittent fasting with the risk of cardiometabolic dysfunction. We also examined the effect of their interactions on cardiometabolic risks. Furthermore, since major differences exists between Ramadan diurnal intermittent fasting compared to other forms of experimental intermittent fasting, in this article, we further restricted the discussion to Ramadan diurnal intermittent fasting. PubMed and Google Scholar databases were searched using “intermittent fasting,” “time-restricted feeding,” “fasting,” “mealtime,” “circadian rhythm,” and “cardiometabolic risk,” focusing on human studies published after 2013. Recent evidence indicates that meal timing may influence circadian rhythm, as a result, it may also directly or indirectly impact cardiometabolic risk. In humans, several studies suggested that late mealtime is related to an increased risk of poor cardiometabolic health. Nevertheless, large clinical interventional studies are required to assess causality between late mealtime and cardiometabolic morbidity. Currently, evidence indicates that Ramadan diurnal intermittent fasting has several beneficial effects that may reduce the risk of cardiometabolic disorders, such as weight reduction, improvement in lipid profile and glycemic control, reduction in proinflammatory markers, and oxidative stress. Nevertheless, several changes in daily lifestyle routine, happening during the Ramadan month, may affect the all measured markers of cardiometabolic diseases. Summarily, no definitive conclusion about the impact of Ramadan intermittent fasting on oxidative stress can be formulated. Therefore, large, well-designed studies, which control for various confounding factors are required to assess the influence of Ramadan diurnal intermittent fasting on markers of cardiometabolic risk and disorders.

Highlights

Cardiometabolic disorders, a major health problem, is among the main causes of increased morbidity and mortality [1]
Desynchronization of the circadian system has been linked to several cardiometabolic disorders, including impaired glucose tolerance, reduced sensitivity to insulin, increased markers of systemic inflammation, increased blood pressure, decreased energy expenditure, and increased weight
Animal studies indicate that eating during the wrong time of the day causes a misalignment between the peripheral circadian clocks and the central clock in the suprachiasmatic nucleus (SCN), which increases the risk of developing cardiometabolic diseases

Summary

INTRODUCTION

Cardiometabolic disorders, a major health problem, is among the main causes of increased morbidity and mortality [1]. Cardiometabolic risk denotes risk factors that increase the chances of developing vascular events or developing diabetes and obesity. This conception comprises diseases, environmental, behavioral and genetic factors, such as hypertension, dyslipidemia, poor eating habits, and smoking, in addition to recently described risk factors, such as central obesity, systemic inflammation, and genetics [2, 3]. Disturbances of circadian rhythm disrupt body functions and may increase the risk of cardiometabolic dysfunction [5]. We critically reviewed studies that examined the effect of IF, mealtime, and circadian rhythm; in addition to their interactions on cardiometabolic risks

SEARCH METHODS

SUMMARY