Effect of diurnal intermittent fasting during Ramadan on ghrelin, leptin, melatonin, and cortisol levels among overweight and obese subjects: A prospective observational study

PLOS ONE RESEARCH ARTICLE Effect of diurnal intermittent fasting during Ramadan on ghrelin, leptin, melatonin, and cortisol levels among overweight and obese subjects: A prospective observational study Natheer Al-Rawi1, Mohamed Madkour2, Haitham Jahrami3,4, Dana Salahat2, Fatima Alhasan2, Ahmed BaHammam5,6, Mo’ez Al-Islam Faris ID7* a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Department of Oral and Craniofacial Health Sciences, College of Dental Medicine/Research Institute of Medical and Health Sciences (RIMHS), University of Sharjah, Sharjah, UAE, 2 Department of Medical Laboratory Sciences, College of Health Sciences/Research Institute of Medical and Health Sciences (RIMHS), University of Sharjah, Sharjah, UAE, 3 Rehabilitation Services, Periphery Hospitals, Ministry of Health, Manama, Bahrain, 4 College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain, 5 Department of Medicine, College of Medicine, University Sleep Disorders Center, King Saud University, Riyadh, Saudi Arabia, 6 The Strategic Technologies Program of the National Plan for Sciences and Technology and Innovation in the Kingdom of Saudi Arabia, Riyadh, Saudi Arabia, 7 Department of Clinical Nutrition and Dietetics, College of Health Sciences/Research Institute of Medical and Health Sciences (RIMHS), University of Sharjah, Sharjah, UAE * , OPEN ACCESS Citation: Al-Rawi N, Madkour M, Jahrami H, Salahat D, Alhasan F, BaHammam A, et al. (2020) Effect of diurnal intermittent fasting during Ramadan on ghrelin, leptin, melatonin, and cortisol levels among overweight and obese subjects: A prospective observational study. PLoS ONE 15(8): e0237922. https://doi.org/10.1371/journal. pone.0237922 Editor: Nayanatara Arun Kumar, Kasturba Medical College Mangalore, INDIA Received: January 20, 2020 Accepted: August 6, 2020 Published: August 26, 2020 Peer Review History: PLOS recognizes the benefits of transparency in the peer review process; therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. The editorial history of this article is available here: https://doi.org/10.1371/journal.pone.0237922 Copyright: © 2020 Al-Rawi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Background Levels of cortisol, melatonin, ghrelin, and leptin are highly correlated with circadian rhythmicity. The levels of these hormones are affected by sleep, feeding, and general behaviors, and fluctuate with light and dark cycles. During the fasting month of Ramadan, a shift to nighttime eating is expected to affect circadian rhythm hormones and, subsequently, the levels of melatonin, cortisol, ghrelin, and leptin. The present study aimed to examine the effect of diurnal intermittent fasting (DIF) during Ramadan on daytime levels of ghrelin, leptin, melatonin, and cortisol hormones in a group of overweight and obese subjects, and to determine how anthropometric, dietary, and lifestyle changes during the month of Ramadan correlate with these hormonal changes. Methods Fifty-seven overweight and obese male (40) and female (17) subjects were enrolled in this study. Anthropometric measurements, dietary intake, sleep duration, and hormonal levels of serum ghrelin, leptin, melatonin, and salivary cortisol were assessed one week before the start of Ramadan fasting and after 28 days of fasting at fixed times of the day (11:00 am-1:00 pm). Results At the end of Ramadan, serum levels of ghrelin, melatonin, and leptin significantly (P<0.001) decreased, while salivary cortisol did not change compared to the levels assessed in the pre-fasting state. PLOS ONE | https://doi.org/10.1371/journal.pone.0237922 August 26, 2020 1 / 15 PLOS ONE Data Availability Statement: Data underlying the study is available on the data repository: https:// figshare.com/s/31c1c984b1e6e3f63d07. Funding: This work was supported by a ViceChancellor Research and Graduate Studies Office/ University of Sharjah grant no. (VCRG/R1061/ 2016). Ramadan fasting, ghrelin, leptin, melatonin, and cortisol Conclusions DIF during Ramadan significantly altered serum levels of ghrelin, melatonin, and serum leptin. Further, male sex and anthropometric variables were the most impacting factors on the tested four hormones. Further studies are needed to assess DIF’s impact on the circadian rhythmicity of overweight and obese fasting people. Competing interests: The authors declare they have no competing interests. Abbreviations: BIA, Bioelectrical impedance analysis; BMI, Body mass index; DIF, Diurnal intermittent fasting; ELISA, Enzyme-linked immunosorbent assay; HC, Hip circumference; HDL, High-density lipoprotein cholesterol; LDL, Low-density lipoprotein cholesterol; METs, Metabolic equivalents; SD, Standard deviation; STROBE, Strengthening the Reporting of Observational Studies in Epidemiology; UAE, Sharjah, United Arab Emirates; WC, Waist circumference.. Introduction Circadian rhythms are mental, physical, and behavioral changes that follow a daily cycle, which respond primarily to light and darkness in an organism’s environment [1]. Circadian rhythm has a direct effect on metabolic processes and the regulation of energy balance [2]. Certain behaviors such as the timing of food abstinence and intake may affect circadian rhythms [3–6]. Levels of cortisol, melatonin, ghrelin, and leptin are highly correlated with circadian rhythmicity; the levels of these hormones are affected by sleep, feeding, and general behaviors, and fluctuate according to the light-dark cycle [7]. Recurrent circadian fasting during Ramadan is a form of diurnal intermittent fasting (DIF) or time-restricted feeding that is practiced by more than 1.5 billion Muslims every year. This special form of religious fasting is characterized by its duration and continuity (no break between fasting days) [8–11]. Such type of fasting involves complete abstinence from food and drink, even water, from dawn to sunset. During Ramadan, several changes have been reported in dietary habits, meal frequency, and timing [12–14], and sleep patterns [15, 16]. The extent of these changes differs culturally and is associated with variable intakes of fatty and sweet foods and beverages [17, 18]. Such dietary changes are resulting in variable effects on body composition [10], metabolic syndrome components [19], genetic expressions [11], and oxidative stress and inflammatory markers [20]. During DIF of Ramadan, two to three meals are consumed after sunset: a light meal or breakfast at the moment of declaration of sunset prayer time (Athan Al-Maghrib), dinner following nightly prayer in some countries (about one to three hours after sunset), and a predawn meal (Suhur). People in other countries take one large meal at the sunset (...truncated)