Differences in leptin, ghrelin, and glucagon-like peptide-1 levels between religious fasting and normal fasting

Background/aim: Leptin, ghrelin, and glucagon-like peptide-1 (GLP-1) affect hunger, satiety feelings, and food intake. We hypothesized that during Ramadan, if the brain knows that the body will be hungry until sunset, there may be differences between leptin, ghrelin, and GLP-1 levels in Ramadan and non-Ramadan fasting. Materials and methods: This study had two phases. In the first phase, the participants were asked to skip the dawn meal of Ramadan (suhur), so that 12 h of fasting could be achieved. Participants ceased food intake at midnight, and at noon blood was drawn. Eight participants were selected as a subgroup. These participants gave blood three times a day to detect hormonal changes during Ramadan. Six months later, in the second phase, blood samples were obtained at noon from participants after 12 h of fasting. Results: Analysis was conducted on 30 patients [19 males (63.3%) and 11 females (36.7%)]. There was a significant difference in leptin, ghrelin, and GLP-1 levels between Ramadan fasting and non-Ramadan fasting (P = 0.04, P = 0.02, and P < 0.001, respectively). In the subgroup analysis, there was no statistically significant difference in leptin, ghrelin, and GLP-1 levels over time. Conclusion: The results of this study suggest that the nervous and gastrointestinal systems may behave differently in religious fasting than in nonreligious fasting.