Fasting on Yom Kippur with Diabetes

With Yom Kippur – one of the holiest days of the Jewish year – many people are preparing for their fast, which is observed from sundown one day to sundown the next day. For people with diabetes, fasting can sometimes be challenging, but with the right precautions, fasting can be done in a safe and healthy environment.

Is fasting required?

Although fasting is an important aspect of Yom Kippur, the Torah states that fasting is not required, especially if it puts your health at risk. This includes children, pregnant or breastfeeding women, the elderly and anyone who might make themselves ill by fasting. This also includes people with poorly controlled diabetes, and specifically, people with type 1 diabetes, who take insulin or type 2 on a mixed insulin regimen or those who often have very high or very low blood glucose levels.

How to Fast Safely When You Have Diabetes

Fasting for people who have diabetes is a tricky area that brings the desires and wishes of the person contemplating the fast in conflict with the need to consume adequate nutrition in order to avoid the complications of blood glucose excursions in either direction. The level of risk associated with fasting depends on diabetes type, control level, medication regimen, and current physical condition.

In general, the risk level is low in those whose diabetes is controlled through dietary means alone or with oral agents that do not stimulate insulin secretion from the pancreas. It increases for those on oral medications that promote insulin secretion, becoming highest for those with type 1 diabetes.

The risks associated with fasting are related to the subversion of normal physiological processes in people with diabetes. When people without diabetes fast, glucose levels are depressed, which reduces the amount of circulating insulin. Simultaneously, levels of glucagon and epinephrine rise, which releases glucose from liver glycogen. If fasting continues beyond a few hours, glycogen stores become depleted and fatty acids are released from the fat cells to be oxidized into ketones. The skeletal muscle and several organs will burn ketones for energy, thereby sparing available glucose for use by the brain.

In patients with type 1 diabetes, life-long recurrent episodes of hypoglycemia and autonomic neuropathy may blunt the normal response to fasting. When people are hypoglycemic repeatedly the body isn’t able to replenish glycogen stores adequately. In the face of inadequate reserves of glycogen, the liver can’t secrete glucose to prevent hypoglycemia. Furthermore, during fasting, patients with type 1 still require some level of basal insulin. Patients may not realize the need for insulin and omit coverage. Prolonged fasting in the face of insulin deficiency can lead to a situation where the brain is deprived of glucose because there isn’t sufficient insulin available to move glucose from the bloodstream into the cells. This stimulates the overproduction of ketone bodies and ultimately ketoacidosis, a potentially fatal situation.

In patients with type 2 diabetes alternations in insulin and glucagon response are not as dramatic and the development of ketoacidosis is not usually a concern. However, hyperglycemia can be as significant a problem as can hypoglycemia. In patients with type 2 diabetes, the liver often over secretes glucose in the fasting state leading to the hyperglycemic condition called the Dawn phenomenon.

Most religions do not obligate people who are ill to fast. In fact, the opposite is true; fasting is usually actively discouraged. Yet, people with diabetes may not consider their condition a manifestation of acute illness, or they may feel the spiritual benefits of fasting outweigh the risk.

All people with diabetes who are contemplating fasting should

  1. Discuss their intention with their medical team
  2. Be in good physical condition and well hydrated
  3. Check their blood glucose frequently during the fast
  4. Have insulin (if taking insulin) and fast-acting carbohydrates available for low and high blood glucose
  5. Stop the fast if hypoglycemia results or if hyperglycemia above 250mg/dl with ketones occurs

Although this content is reviewed by Joslin Diabetes Center healthcare professionals, it is not intended to replace the medical advice of your doctor or healthcare provider. Please consult your healthcare provider for advice about a specific medical condition.