Muslims worldwide observe total fasting (no food or water) between dawn to sunset in the month of Ramadan. They do so not for losing weight or any medical benefit, but as it is ordained in Qur’an which says.
“O you who believe! Fasting is prescribed to you, as it was prescribed for those before you (i.e. Jews, & Christians) so that you may (learn) self-restraint.”(Surah Al-Baqarah, 2:183)
According to Islamic Laws, children below the age of 12, sick patients, travelers, and women who are menstruating or nursing a baby are exempt from fasting. In addition to staying away from food or water for the whole day, they are asked to stay away from sex, smoking or misconduct during the period of fast. In addition, they are encouraged to do more acts of piety i.e. prayer, charity, or reading Qur’an during this month.
Food is needed by the body to provide energy for immediate use by burning up carbohydrates, that is, sugar. Excess of 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 receptor. Obese people lack receptor; therefore, they cannot utilize their insulin. This leads to Insulin Resistance and 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.
On the basis of human physiology described above, semi-starvation (ketogenic) diets have been devised for effective weight control. These diets provide calculated amount of protein in divided doses with plenty of water, multi-vitamins, etc. These effectively lower weight, blood sugar, but because of their side effects, should be used only under supervision of physicians.
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.” It must be pointed out, however, that there are also many adverse effects of total fasting. That includes hypokalemia and cardiac arrhythmia associated with low calorie starvation diets used in unsupervised manner.