The aim of this study was to evaluate the changes in abdominal fat distribution in the fasting month of Ramadan. Thirty-eight healthy volunteers (17 women and 21 men) who fasted in the month of Ramadan in 2002 were included in this prospective study. Waist, hip and thigh circumferences, weight and height of all subjects were measured. Waist-to-hip ratio (WHR), waist-to-thigh ratio (WTR) and body mass index (BMI) were calculated for each subject. For assessing the fat distribution in the abdomen, computed tomography (CT) was performed. Both subcutaneous and visceral fat areas were calculated by the CT scanning technique. All of the calculations were done before (first measurement) and after (second measurement) Ramadan fasting and the changes were evaluated. No statistically significant differences were found in all subjects between the first and second measurements, which include total, subcutaneous and visceral fat areas, waist, hip and thigh circumferences, weight, BMI, WHR, and WTR (p > 0.05). In females and the individuals in their twenties, there was a significant decrease in visceral fat area (p < 0.05). Despite of the general opinion that supposes the change of weight during the fasting month of Ramadan, there were no significant differences in weight and abdominal fat distribution. However in female and young individuals, there was a reduction in visceral fat compartment. This could be due to fat redistribution, because they have more physical activity than males and older individuals. (C) 2004 Tohoku University Medical Press.