Fasting, an important part of religious observance for many people, is defined as voluntarily or willingly not eating or drinking for varying lengths of time or for a defined period. Some people may abstain from only food and still drink liquids during their fast while others may have a fast that there is a set time each day that they avoid all food and drinks. For example, in the Muslim religion, Ramadan is the most sacred month of the year and during its 29-30 days, Muslims are obligated to fast from sunrise to sunset. When the sun sets, there is a communal meal called Iftar where the fast is broken and a meal is typically enjoyed with friends and family.
Many religions will have exemptions for fasting. In the Muslim religion exemptions are emphasized in the religious scripture. These exemptions include menstruating women, pregnant and breastfeeding women, children, individuals with acute or chronic diseases or those who are sick, the elderly, and those who are traveling.
Those at risk for complications
For people who are healthy and have no underlying medical conditions, fasting usually will not cause any harm, but for those with diabetes, precautions should be taken.
You may have a high risk of complications while fasting if you have one or more of the following:
- Type 1 diabetes
- Type 2 diabetes with poor blood glucose control
- Recent history of severe low blood glucose or diabetic ketoacidosis
- History of recurring low blood glucose or unawareness of low blood glucose
- Conditions such as severe kidney disease or blood vessel complications
- Diabetes and are pregnant
When planning a fast and you have diabetes, it is important to be prepared so you can fast safely. Schedule an appointment with your healthcare provider and diabetes care team before the start of your fast to discuss if fasting is safe for you and to review the best plan during fasting to help keep your blood glucoses well controlled.
Let’s look at some precautions that you can take to prepare safely for a fast.
Blood glucose monitoring
Make sure you have a glucose meter and that you know how to use it. Monitoring blood glucoses should be done often while you are fasting. Plan to check your blood glucose at least four times a day and more often if you are showing signs of a low or high blood glucose. Signs of a low blood glucose may include feeling shaky, dizzy, sweaty or having a fast heartbeat. Signs of a high blood glucose may include excessive thirst, feeling very hungry, frequent urination or blurry vision. Checking your blood glucoses often will give you a better understanding of your blood glucose patterns during this time of fasting. It will also help to see any blood glucose readings which may be trending up or down and may need attention.
Medication
When meeting with your healthcare team prior to fasting, discuss your fasting plan with them including what hours of the day you will be fasting and which hours of the day you will be eating and drinking. Your healthcare provider may make medication adjustments that will work better with the times you will and won’t be eating. Since your meal timing and usual eating patterns will be different, adjusting medication may help with preventing high and low blood glucoses.
Stay well hydrated
If able to drink during your fast, this should not be an issue. If you cannot have liquids during your fast, plan to drink water and fluids during your non-fasting hours. Stay away from sweetened beverages and juices as they may be too high in carbohydrates. Consume fruits and vegetables during your non-fasting hours also, as these are high in water content and can help you stay hydrated. Be aware of the signs of dehydration which include dizziness, increased thirst, dry mouth, weakness and headache.
Exercise
Keep your body moving but choose moderate to light physical activity. Strenuous activity may be difficult when fasting and can cause fluctuations in blood glucoses. Always monitor blood glucoses before and after activity and it may be best to plan activity around a mealtime.
While having a plan in place is a good start and can help keep you safe during your fast, breaking your fast may be necessary, particularly if your blood glucose is too low (less than 70mg/dl). Treating a low blood glucose is an urgent matter and requires immediate attention. The best plan is to consume 15 grams of fast-acting carbohydrates such as glucose tablets or 4 oz of juice to help bring up your blood glucose. Retest your blood glucose in 15 minutes to make sure it is above 70mg/dl. If it remains below 70 mg/dl take an additional serving of 15 grams of fast-acting carbohydrates. Then it is beneficial to eat a small snack or meal to keep blood glucoses from dropping again.
Know the risks of Diabetic ketoacidosis
An elevated blood glucose is also an urgent matter and will need attention. If blood glucoses are elevated (240mg/dl or over) you may need medication adjustments, particularly if you are on insulin- which may require you to take extra. Contact your healthcare provider to discuss the best plan for you. Taking additional insulin does not break your fast. Untreated high blood glucoses can lead to Diabetic ketoacidosis (DKA) in those with type 1 diabetes, this is why it is important to treat high blood glucoses as soon as possible.
DKA requires immediate medical attention and can come on quickly. Signs of DKA can include high blood glucose with nausea, vomiting, stomach pain, excessive thirst, drowsiness, and deep shallow breathing that has a fruity smell. If not treated, you can fall into a coma. Dehydration can also be exacerbated when blood glucoses are elevated. If showing signs of dehydration consuming fluids may be necessary.
Breaking your fast
When it is time to break your fast and have your meal, you should choose a balanced and healthy meal. A combination of whole grain, lean meats, non-starchy vegetables and healthy fats can help stabilize your blood glucose levels and keep you satisfied. An easy tool to help you choose a healthy meal is to follow the healthy food plate model of ½ of your plate filled with non-starchy vegetables such as salads or cooked vegetables, ¼ of your plate filled with whole grains such as brown rice, potato, or whole wheat pasta, ¼ of your plate filled with protein rich foods such as fish, meat, eggs or beans. Remember to hydrate during this time and in all non-fasting hours.
Fasting is often part of a meaningful and special time in your life. It can be done safely if appropriate precautions are taken. Always discuss a fasting plan with your health care team and be prepared to manage your blood glucoses and keep yourself safe while fasting.