What would happen if a diabetic fasted for 24 hours or more?
I have answered a similar question before. The answer is that depending upon how acute the diabetes is, the type of diabetes (type I or II), the person may survive or die. I will speak with the severe type II diabetic in mind.
Diabetes is a result of severely impaired glucose tolerance. The body cells are unable to absorb and process glucose from the blood. After eating, the blood sugar level (BSL) rises rapidly. Medication helps to regulate the BSL. Gradually, the kidneys filter out the excess glucose from blood that passes thru urine. Sweat glands also filter out sugar via sweat. BSL keeps dropping as time passes by.
Because the insulin is insufficient to regulate BSL, the level then starts dropping rapidly because the person is fasting. When the sugar drops to 70 mg/dL, the person starts feeling giddy, tired, the legs feel wobbly, and person wants to rest. After this point, the BSL starts dropping rapidly. Within 30 mins to an hour, the BSL drops to 40 or less. This condition is known as hypoglycemia. At this point, the body starts shutting down various organs as there is no glucose to energise them. This results into a diabetic coma. Immediate admittance to a hospital ICU is needed with infusion of glucose saline water into the vein. Any delay can result into brain damage, various organs' damage, or death.
A diabetic should never fast for 24 hours, even if mildly diabetic. The diabetic should follow regular meal times. Any (religious) fasting should be done under the watchful eye of close ones. A diabetic should always carry some candy or drink a sugary drink if he starts feeling restless because of great delay in did intake.