Many people recognize Ramadan as a month to stay awake at night and sleep during the day. This lifestyle however, varies from one Muslim country to another, where the customs prevailing in the society affect the pattern of a person's life during the holy month.
The sudden change of eating habits and timing, from day to night (fasting during daytime and eating at night) are accompanied by some physiological changes in the body.

FAQs:

Does fasting during the holy month of Ramadan lead to excessive sleepiness?
To answer this question we need to have further discussions. We need to know the exact difference between the effect of fasting on body’s physiology, and the effect of change in lifestyle during the holy month and consequently its effect on the sleep.

How is the sleep affected by the lifestyle change during the holy month?
Many people associate Ramadan with late night meals, which change the lifestyle of the community. During Ramadan work starts late, markets open in the evening, and the social meets with relatives and friends increase. As a result, one faces acute lack in sleep during the night. All this causes laziness, sleepiness, and mood swings during the day.
In one of the studies based on a set of students (sample size - 56), we found that there is no difference in the duration of sleep during Ramadan and Sha'ban months, i.e. they slept for the same no. of hours a day during Sha'ban and the initial three weeks of Ramadan.
The difference however, was in the sleeping and waking up time. The students' sleeping time changed from 11:30 pm to about 3:00 am, in the first week of Ramadan. The waking up time was gradually delayed from 6:30 am to 8:45 am within the first week of Ramadan and reached 9:15 am in the third week.

It was observed that the students complained of sleepiness during the day in Ramadan, in spite of sleeping for the same duration. This may be due to the sudden change in waking up and sleeping schedule, the potential physiological changes of fasting such as alterations in melatonin secretion, or the possibility of some psychiatric factors or mood swings that accompany fasting and affect the sleep. The earlier possibilities are still theoretical and unconfirmed