Intermittent fasting (IF) and it's relationship with chronotype and sleep quality

This study aims to evaluate the relationship between intermittent fasting (IF) diet adherence, chronotype, and sleep quality. The research was conducted as a cross-sectional study with a total of 264 participants, including 232 women and 32 men, aged 19-64, residing in Mardin province. Participants were categorized based on their diet regimens into the following groups: IF only (%30,3), IF+Mediterranean diet (%4,9), IF+low carbohydrate diet (%30,7), IF+classic calorie-restricted diet (%4,5), Ramadan fasting (%10,2), and those not following any specific diet (%19,3). General descriptive characteristics and some anthropometric measurements of the participants were recorded by the researcher. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality, and the Morningness-Eveningness Questionnaire was used to evaluate chronotype characteristics. It was found that 9.5% of participants had an evening chronotype, 61% had an intermediate chronotype, and 28.5% had a morning chronotype. While 34.1% of the participants were found to have good sleep quality, 65.9% had poor sleep quality. Significant statistical differences were observed in the Morningness-Eveningness Questionnaire based on the type of diet (p=0.031). Individuals who followed only the IF diet were closer to the morning chronotype compared to those who did not follow any diet (p<0.05), while those who practiced Ramadan fasting were closer to the evening chronotype compared to those who only followed the IF diet (p<0.05). Significant statistical differences were also found in the total PSQI scores based on the type of diet (p=0.001). It was determined that individuals following the IF + Mediterranean diet and IF + low carbohydrate diet had better sleep quality compared to those who did not follow any diet (p<0.05). These effects were observed in individuals who had been following the IF diet for 2-6 months or longer (p=0.198). According to the results of multiple linear regression analysis, the implementation of only the IF diet and coffee consumption in the morning were associated with the morning chronotype, while the IF + Mediterranean diet was associated with good sleep quality. Intermittent fasting diets may be a viable option for healthy individuals seeking to approach a morning chronotype and improve sleep quality, depending on the working conditions.