Level of sugar decreases in blood. This makes the body rely on providing the needed calories for metabolism by burning sugar stored in the body. Glycogen stored in the liver, &fats in tissues are decomposed & transferred into calories & energy needed by the body. This results in moderate shortage of body weight. Therefore, fasting is considered of great value for overweight persons&stable non-insulin diabetes. 

{When Allah asks us to leave food it doesn't mean he wants to punish us but  there r many benefits in it which r somtimes NOT visible or kept secret, Allah is Alim ul Hakeem, he is well aware when its good for us to eat&drink & when its better to stop} #RamadanKareem