Intermittent Fasting for People with Diabetes

fasting and diabetes

If you’re reading this, chances are you have diabetes. Diabetes can be a frustrating and sometimes debilitating disease to manage, especially when it comes to maintaining a healthy weight. 

Since diabetes can make your weight challenging to manage, you may have considered intermittent fasting. Like everything, intermittent fasting has pros and cons if you’re diabetic. Fortunately, there’s plenty of research on diabetes and intermittent fasting to help you decide if intermittent fasting is right for you.

Diabetes in a Nutshell

intermittent fasting for diabetes

Diabetes is a group of diseases related to your body’s inability to remove sugar from your bloodstream adequately. According to the American Diabetes Association, just over 35 million Americans had diabetes in 2018. That’s 10.5 percent of the population and about 1.5 million new diagnoses yearly. 

There are several different diabetes types, but the most common ones are Type 1 and Type 2.  Approximately 1.6 million Americans have type 1 diabetes, an organ-specific autoimmune disease. With type 1 diabetes, your body’s immune system attacks your pancreas, the organ responsible for creating insulin. If you suffer from type 1 diabetes, your pancreas produces little or no insulin, which leaves you unable to regulate the amount of glucose in your bloodstream.   

Type 2 diabetes, sometimes referred to as adult-onset diabetes, begins as pre-diabetes, which means you have chronically elevated blood sugar usually caused by your eating plan. When you’re pre-diabetic, it will progress to when your body can no longer produce enough insulin to remove sugar from your blood and convert it into usable energy.

According to the CDC, about 88 million people in the US are pre-diabetic and 34.2 million individuals have type 2 diabetes. This common illness quickly leads to other health problems like kidney failure, vision loss, limb amputation, and heart disease. 

Preventing and Curing Type 2 Diabetes

If you’re pre-diabetic, you can delay or prevent the onset of type 2 diabetes by paying closer attention to the type of carbohydrates you eat, how often you eat them, and what other foods you eat with your carbohydrates. 

For some reason, doctors are hesitant to say you can cure your diabetes. Instead, they’ll say your diabetes is ‘in remission’ when you successfully manage your blood sugar levels.

Controlling your blood sugar is how you’ll treat your type 2 diabetes. You can control your blood sugar with exercise and healthy food choices. There are medications that help your body produce more insulin and become more insulin sensitive. Medications can lower your blood sugar, slow your digestion, or help your kidneys filter glucose from your bloodstream. If you have type 2 diabetes, you can take insulin to boost the amount of insulin working to clear glucose from your bloodstream. 

Recently, scientists studied the effects of intermittent fasting (IF) in diabetic patients, as IF reduced their blood sugar, increased insulin sensitivity, and increased their ability to lose weight, which all help mitigate diabetes. 

The Science Behind Intermittent Fasting for Diabetes

We need more research on IF and diabetes, but early studies show intermittent fasting is effective in improving diabetes symptoms. 

A 2019 Norwegian study on mice found intermittent fasting reduces pancreatic fat. The study sheds light on how fat cells might trigger the overproduction of insulin from the pancreas, resulting in pancreatic fatigue and, eventually, failure to produce insulin at all. 

A comprehensive review of intermittent fasting literature for people with diabetes was conducted in April of 2019. The study provides guidelines for clinicians whose patients are interested in intermittent fasting as a means of diabetes mitigation. So, without further adieu, here are the pros and cons of intermittent fasting for diabetes control.

Benefits of Fasting for Diabetes

Weight Loss

If you’re diabetic and overweight or obese, it’s essential for you to lose excess body fat. . Intermittent fasting is effective as a tool for weight loss, and it’s far more effective than restricting your calories. IF will also help you hang on to your muscle mass, which is crucial for maintaining a healthy weight.  

Weight loss decreases pancreatic fat and can reduce fat in your liver. Fatty liver disease occurs frequently in patients with diabetes and the conditions exacerbate each other.  

There’s a link between weight loss and lower hemoglobin A1C levels, and intermittent fasting may improve both body weight and A1C numbers if you’re diabetic. The A1C is a measure of your blood glucose levels over the last three months and is commonly used to diagnose prediabetes or diabetes.  

Weight loss also lowers your risk of heart disease. If you’re diabetic, the most common cause of death is heart disease or stroke, partly because your high blood sugar can lead to blood vessel damage. A recent study shows intermittent fasting improves the markers of heart disease risk. 

Insulin Sensitivity

Intermittent fasting improves insulin sensitivity in part due to a decrease in visceral fat. However, even in healthy subjects who maintain their body weight, intermittent fasting improves insulin sensitivity. 

In 2018, a limited study of just three diabetic patients resulted in all three discontinuing their insulin and other medications thanks to intermittent fasting. While this research is promising, we need more studies on larger and more diverse populations. 

Metabolic Switching

Metabolic switching is a phenomenon that occurs when you go without food long enough that your body begins to use your stored fat as fuel instead of sugar. Intermittent fasting induces this ketogenic state and is an oft-cited benefit for those who fast for weight loss and fat burning. 

If you’re pre-diabetic or diabetic, ketosis can benefit both your liver and pancreas. Your liver won’t need to store excess glucose as glycogen (glucose is depleted after 12 hours or more with no food) and your pancreas can take a break from the overproduction of insulin. 

Risks of Fasting for Diabetes Control

If you’re new to intermittent fasting you may experience hunger pangs, fatigue, or headaches as your body adjusts to a new fuel schedule; especially if you’ve been following an eating pattern high in simple carbohydrates. And if you’re diabetic, there are unique risks to intermittent fasting. 

Hypoglycemia & Hyperglycemia

Hypoglycemia can occur if your blood sugar falls dangerously low. You may feel shaky, light-headed, or faint. And it’s rare, but you could slip into a coma. As a diabetic, your risk for Hypoglycemia increases if you fast. 

Also, your diabetes medications already put you at risk for hypoglycemia, which makes combining your medication with fasting potentially dangerous. 

A 2018 study due to the risk of hypoglycemia in patients with type 2 diabetes who fasted found participants experienced positive results in weight loss, reduction of A1C levels, improved fasting glucose levels, and improved quality of life. But they were at a higher risk for hypoglycemia than the control group. The risk remained high even though they reduced their medications, regardless of the type of fasting they were doing. 

On the opposite end of the spectrum, hyperglycemia is a dangerous condition that can occur if you have extremely high blood sugar. Prolonged hyperglycemia can lead to micro and macrovascular issues, like loss of vision and heart disease. In some cases, extremely high blood sugar can lead to a coma as a result of diabetic ketoacidosis. For these reasons, it is essential that you pay attention to the balance of carbohydrates in your meals. Try not to break your fast with a high-carbohydrate meal or snack;  have a healthy balance of carbs, fats, and proteins instead so you don’t spike your blood sugar too high.

Disordered Eating

intermittent fasting diabetes

If controlling what or when you eat is a challenge, intermittent fasting may not be for you. According to the American Diabetes Association, if you have type 1 or type 2 diabetes, you’re more likely to have experienced disordered eating and are at higher risk for developing an eating disorder.  

If you go for an extended period without food, it could cause you to binge when your fasting window is over. This is unhelpful for anyone participating in intermittent fasting but can be particularly dangerous if you’re diabetic since it can trigger a hyperglycemic state. 


Keep in mind that you typically get 20% of the water you need from your food. It can be easy to forget to drink water during your fasting window, but this can put you at risk for dehydration. Diabetes increases your risk for dehydration because high blood sugar pulls water from your body (excessive thirst can be a symptom of diabetes). If you have diabetes, drink water regularly during your fasting window. 

Can You Participate in Intermittent Fasting?

Researchers aren’t sure which intermittent fasting method is best for you if you’re pre-diabetic or diabetic. You should talk with your doctor before beginning an intermittent fasting protocol; especially if your diabetes treatment includes medication. Your doctor will help you understand how to check your blood sugar more frequently, and can recommend adjustments to medications as needed.

If your doctor thinks the 16:8 method would be appropriate for you, or maybe even a less strict method, ease into it by fasting for one or two days per week. Be mindful of how you feel and remain aware of the early signs of hypoglycemia, such as lightheadedness. If you do feel hypoglycemic, don’t hesitate to break your fasting window – your health is a priority.

Use caution when you exercise or participate in activities that can potentially reduce your blood sugar, and be sure to stay hydrated by drinking water regularly throughout the day. 

Doctors and scientists recognize the potential use of intermittent fasting as a therapeutic treatment for diabetes. These benefits arise as a secondary benefit of weight loss, and from the unique changes to metabolic pathways that occur as a result of fasting. 

After more randomized tests are done, it’s likely IF will become a standard in diabetes care. Until then, fasting is safe for you under the supervision of your healthcare provider and with increased glucose monitoring. 

Author's bio


Sara-Mai Conway

Sara-Mai is a writer who specializes in physical and mental health, nutrition, and fitness. She has 20 years of professional experience in the health and wellness industry and is a certified yoga instructor.