ramadan fasting: evidence or expert opinion? results of preliminary studies

each year, over a billion muslims fast worldwide during the month of ramadan.  through this religious practice, not only will one have spiritual growth, but can improve his/her diet, which is of pivotal importance in this month. conversely, the available evidence regarding the health benefits of ramadan fasting is scarce and highly contentious. although islam exempts patients from fasting, many of them fast conceivably and their clinical condition is prone to deteriorate. this is due to the persistent gap between current expert knowledge and conclusive, strong evidence regarding the pathophysiologic and metabolic alterations by fasting, and the consensus that healthcare professionals should reach, in order to manage various patient groups during this month. in this review, we summarize the results of our initial studies regarding the effects of ramadan fasting on some clinical conditions including alterations of body composition. we also go through the important clinical results of patients who have had previous history of cardiovascular disease, type 2 diabetes, asthma and renal colic. our studies have presented some evidence in favor of ramadan fasting and encourage those with mentioned diseases to consult their physicians and follow medical and scientific recommendations. we attempt to present some relevant evidence clarify future scopes in this area of study, and provide suggestions for future investigations.