This study aimed to evaluate the effect of diurnal Ramadan fasting on cardiometabolic risk factors (blood glucose, lipid profile, inflammatory cytokines) and sleep quality in healthy Turkish adults. This prospective observational study was conducted with a total of 32 individuals (12 males, 20 females) who were aged between 19–32 years and fasted for 25 or more continuous days in Ankara, Turkey between 1 Ramadan 1442 and 30 Ramadan 1442. Individuals applied fasting for 16 hours in the spring season. Blood samples were taken after at least 8 hours of fasting, anthropometric measurements were taken and sleep quality was assessed using The Pittsburgh Sleep Quality Index (PSQI) at the beginning and the end of Ramadan. There was a significant decrease in body mass index (BMI), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) levels during Ramadan fasting (p < .005). There were no changes in lipid profiles and sleep quality. There was a significant increase in fasting blood glucose levels (p < .05); however, this change is within normal limits. There was also a significant relationship between BMI and CRP, IL-6, and TNF-α levels (p < .05). The diurnal Ramadan fasting did not affect lipid profiles and sleep quality in healthy Turkish subjects. However, decreased BMI and inflammatory cytokine levels were observed at the end of Ramadan fasting. More studies are needed to clarify the role of Ramadan fasting in healthy populations.