The majority of them observe total fasting (no food or water) between dawn to sunset in the month of Ramadhaan.  They do so not for losing weight or medical benefit, but for them it is ordained in their noble Book. The Quran says, (which means)“ O you who believe!  Fasting is prescribed to you, as it was prescribed for those before you (i.e. Jews and Christians) so that you may (learn) self-restraint”. [Quran 2:183]

According to Islamic Law, children, sick patients, travelers, and women who are menstruating or nursing a baby are exempt from fasting, in addition to abstinence from food and drink for the whole day, they are asked to refrain from sex, smoking and misconduct during the period of fast.  In addition, they are encouraged to do additional acts of piety, i.e. prayer, charity or reading Quran during this month.

Food is needed by the body to provide energy for immediate use by utilizing carbohydrates, that is, sugar.  Excess carbohydrates, which cannot be used, is stored up as fat tissue in muscles, and as glycogen in liver for future use.  Insulin, a hormone from the pancreas, lowers blood sugar and diverts it to other forms of energy storage, that is, glycogen.  To be effective, insulin has to be bound to binding sites called receptors.  Obese people lack receptors; therefore, they cannot utilize their insulin.  This may lead to glucose intolerance.

When one fasts (or decreases carbohydrate intake drastically), it lowers his blood glucose and insulin level.  This causes breakdown of glycogen from liver to provide glucose for energy need and breakdown of fat from adipose tissue to provide for energy needs.

Total fasting reduces or eliminates hunger and causes rapid weight loss.  In 1975, Allan Cott in his “Fasting as a Way of life” noted that “fasting brings a wholesome physiological rest for the digestive tract and central nervous system and normalizes metabolism”. 

Studies on Islamic Fasting

Dr. Soliman, from the University Hospital, Amman, Jordan has reported that during the month of Ramadhaan 1404 AH (June-July, 1984 AD) healthy Muslim volunteers: 42 males and 26 females, ranging in age from 15-64 and 16-28 years respectively were studied.  They were weighed and their blood levels of cortisol, testosterone, Na, K, urea, glucose, total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides (TG) and serum osmolality were measured at the beginning and at the end of Ramadhaan.  There was significant loss of weight in males form a mean of 73.8 +- 6.2 Kg 72.0+- 7.1 Kg (P less than 0.01) and in females from 55.2 +- 4.8 to 54.6 +- 4.2 Kg (P less than 0.05).  Blood glucose levels rose in males from 77.7 +- 23.6 mg.dl to 90.2 mg/dl (P less than 0.05) and in females from 76.0 +- 7 mg/dl to 84.5+- 1.1 mg/dl (P less than 0.002).  All other parameters did not show significant changes.

Dr. F.Azizi and his associates from the University of Medical sciences, Teharan, Iran, has reported the following, serum levels of glucose, bilirubin, calcium, phosphorous, protein, albumin, FSH, LH, testosterone, prolactin, TSH, TI, TI and T uptake, as well as prolactin and TSH responses to TRH were evaluated in group of nine healthy men before and on the 10^th 20^th and 29^th days or Ramadhaan.  Mean body weight decreased from 65.4+- 9.1 to 61.6 +- 9.0 kg at 29^th day. Serum glucose decreased from 82+-4 mg/dl on the 10^th day, and increased thereafter (76+-3 and 84+-5 on the 20^th and 29^th days of fasting respectively).  Serum bilirubin increased from .056 +- 0.17 to 1.43 +- 52 mg/dl on the 10^th days, and decreased thereafter (I.I+- 0.4 on the 20^th and 29^th days.)

All changes returned to basal values four weeks after fasting.  There were no significant changes in serum levels of Ca, P, protein, albumin, and any of measured hormones.  Prolactin and TSH responses to TRH were also unaltered.  He concluded that: (1) intermittent abstinence from food and drink for 17 hours a day for 29 days does not alter male reproductive hormones, hypothalainic-pituitary-thyroid axis or peripheral metabolism of thyroid hormones and (2) physicians caring for Muslims should be aware of change of glucose and bilirubin during Ramadhaan.

Therefore it is concluded from the above two studies that Islamic fasting does not cause any adverse medical effects and may have some beneficial effect on weight and lipid metabolism.