Diabetic patients 
who fast during Ramadan are likely to be at risk of major health complications. Hence, they should fast only if their doctors consider them fit enough, experts say.
The month-long period that is typically marked by long fasting hours during daylight hours is followed by grand feast each evening after sunset (Iftaar), which can be continued till pre-dawn (Sehri).

According to health experts, such long gaps between meals that range from 12 to 15 hours may lead to metabolic changes in the body, that can pose serious health problems for diabetes patients. “If you are diabetic but still want to keep the fast during Ramadan, it is always better to consult your doctor to take all necessary precautionary measures while fasting,” Vikas Ahluwalia, Director (Diabetes and Obesity Center) at the Max Super Speciality Hospital, Saket.

Diabetes is a health condition that occurs when sugar rises in the blood as a result of the deficiency in the insulin hormone or the resistance of the body cells leading to the accumulation of glucose in the blood.
Restriction of fluid intake during such fasts can result in dehydration as well as fluctuations in sugar levels.