Does Intermittent Fasting Help With Diabetes?

About 537 million adults have diabetes worldwide, and the number keeps on getting higher. Lifestyle changes, including intermittent fasting, have proven to be a non-medicinal approach to manage diabetes effectively.

This comprehensive article will cover everything you need to know about intermittent fasting and diabetes, the pros and cons, the recommended fasting types, and tips on how to do intermittent fasting safely.

Key Takeaways:

  • Studies have proven that intermittent fasting helps with diabetes.
  • It improves blood glucose regulation and insulin resistance while reducing body fat and inflammation.
  • 16/8 intermittent fasting is one of the safest and most effective methods to start.
  • People with diabetes should seek their healthcare provider’s approval before starting.

Table of Contents:

History of Intermittent Fasting and Diabetes

Intermittent fasting has ancient roots, tracing back to various cultures and civilizations that practiced fasting for religious, spiritual, or health-related reasons. Fasting has been a part of human history as a means of purification, self-discipline, and cultural or religious observances.

The use of fasting to manage diabetes is debatable, as some scientists note some downsides, which we will cover later. However, current research data suggests intermittent fasting benefits people with diabetes.

Glucose Metabolism:

Before diving into the benefits and downsides, it’s crucial to understand how the body works. Glucose metabolism1 is the process by which the body breaks down carbohydrates from food into glucose, the primary energy source, with the help of insulin.2

In a healthy individual, the pancreas releases insulin to facilitate glucose uptake by cells, where it is used for energy or stored for future use.

Disruptions in glucose metabolism can lead to diabetes. In Type 1 diabetes,3 the body doesn’t produce insulin, while in Type 2 diabetes,4 cells become resistant to insulin.5

Insulin Resistance:

In insulin resistance,6 cells become less responsive to insulin. This means that the sugar we eat can’t enter the tissue cells and accumulate in the blood, leading to elevated blood sugar levels. This condition is a precursor to Type 2 diabetes.7


Prediabetes8 is a condition where blood sugar levels are higher than normal but not yet high enough to be diagnosed as Type 2 diabetes. It serves as a critical stage for intervention to prevent the progression to full-blown diabetes.9

Often, prediabetes is a result of insulin resistance, which is reversible.10

However, it’s important to note that while fasting has the potential to reverse prediabetes and type 2 diabetes, it is not an effective management for type 1 diabetes, which is a type of autoimmune disorder.

Can Intermittent Fasting Help With Diabetes?

Yes, intermittent fasting has been scientifically proven to help with diabetes, especially managing sugar levels, improving insulin resistance, reducing body fat, preventing diabetes complications, and reducing inflammation.

However, it’s crucial to understand that the scientific data available are performed with medical supervision, and doing it without consulting your healthcare provider may be more detrimental than helpful.

Benefits of Intermittent Fasting for Diabetes

diabetes and intermittent fasting

Managing Sugar Levels

For individuals with diabetes, effectively managing sugar levels is crucial. Intermittent fasting offers a structured approach to meal timing that aligns with insulin action, potentially aiding in better blood sugar control.

According to this research on patients with impaired glucose metabolism,11 intermittent fasting reduced fasting blood glucose, HbA1c, and insulin levels among the subjects.

These results are supplemented by a systematic review12 of published literature stating that intermittent fasting is an effective non-medicinal treatment option for type 2 diabetes.

Improving Insulin Resistance

Intermittent fasting may promote this sensitivity by reducing oxidative stress and inflammation and supporting the body’s ability to utilize insulin more efficiently.

Scientific studies exploring the relationship between intermittent fasting and insulin resistance have shown promising results.11 Some research indicates that intermittent fasting can improve insulin sensitivity12 and potentially reverse the early stages of insulin resistance.

The same review states that some patients were able to reverse their need for insulin therapy while doing supervised intermittent fasting.

Reducing Body Fat

Excess body fat, especially around vital organs, is linked to insulin resistance and an increased risk of Type 2 diabetes.

Studies show intermittent fasting is effective in weight loss and improved fat distribution13 among patients with obesity and diabetes. These results also came with better glycemic levels.

Preventing Diabetes Complications

Managing sugar levels and losing weight are among the best ways to prevent diabetes complications,14 two benefits you get when doing intermittent fasting.

Some of the most common diabetes complications15 include heart disease, nerve damage, and kidney disease, which all result from narrowing blood vessels due to continuous elevated blood sugar levels.

However, it’s important to note that to this date, no medication, including metformin and insulin, has proven to prevent complications entirely, and the best way to prevent them is by glycemic control.

Reducing Inflammation

Intermittent fasting has positive effects against inflammation,16 reduces excessive immune reactions and prevents oxidative stress.

People with diabetes always have to deal with inflammation brought about by the immune system reacting to the increased glucose levels. When not managed properly, the immune response causes chronic inflammation, which harms the body’s organs.

Are There Downsides to Intermittent Fasting for Diabetes?

Risk of Hypoglycemia and hyperglycemia

Intermittent fasting can lead to fluctuations in blood sugar levels. For individuals with diabetes, there’s a potential risk of hypoglycemia (low blood sugar), especially if medications are not adjusted accordingly.

On the other hand, there is also a possibility of a sugar spike during fasting, also known as fasting hyperglycemia,17 if the liver spares some glucose. When this happens, constant monitoring and medical advice are crucial.

Adjustment Period

If you’re new to intermittent fasting, you would most likely experience transitional symptoms which may include dizziness, nausea, insomnia, headache, weakness, and more frequency of urination.

You could also experience drying of the mouth and a certain smell of the breath. Increased hydration and reinforcing the fasting with a nutrition-rich meal are necessary.

Nutrient Deficiency

Prolonged fasting periods may result in reduced nutrient intake. This could lead to deficiencies in essential vitamins and minerals, impacting overall health and potentially exacerbating existing health conditions.

To combat this, ask your healthcare provider for supplements recommendations and maintain nutrient-rich meals.

Adherence Challenges

Intermittent fasting requires discipline and adherence to a specific eating schedule. Maintaining this regimen consistently may be challenging for some individuals, potentially leading to irregular eating patterns.

Potential Overeating

Some individuals may compensate for fasting periods by overeating during the designated eating windows. This can counteract the intended benefits and contribute to weight gain, which concerns diabetes management.

Types of Intermittent Fasting for Diabetes

Before diving into the types of intermittent fasting you could try for diabetes, it’s crucial to consult your healthcare provider for any changes in your lifestyle that may affect your blood sugar levels, especially when you want to try fasting.

16:8 Intermittent Fasting

16:8 Intermittent fasting is one of the safest and most effective forms18 as it allows the body to use fat as an energy source, reducing fat actively. However, some individuals may need more time to adjust to this.

This focuses on fasting for 16 hours and getting all the daily calorie requirements within the 8-hour eating period, usually between lunch and dinner.

5:2 Diet

The 5:2 diet is a safe and starter-friendly intermittent fasting19 that involves regular eating for five days a week and restricting calorie intake to around 500-600 calories on two non-consecutive days. On fasting days, individuals typically consume small, nutrient-dense meals or snacks.

Early time-restricted feeding (eTRF)

The Early Time-Restricted Feeding Diet20 (eTRF) is a variant of time-restricted feeding where individuals limit their eating to an early time window within the day, typically finishing their last meal in the afternoon or early evening.

Safe Ways to Do Intermittent Fasting With Diabetes

The decision to do fasting when you have diabetes should not be taken lightly to avoid any complications. Here are a few tips to ensure safety in your intermittent fasting journey:

  • Always seek medical advice: Do not start fasting without your healthcare provider’s approval. They should also keep track of your progress and should monitor metabolic changes for safety purposes.
  • Start slow: Some people can’t tolerate the 16:8 right off the bat, so you can start with the 5:2 diet and work your way up there. Always listen to your body.
  • Monitor sugar levels regularly: Monitoring your sugar levels will help you identify whether fasting works and notify you if you develop fasting hyperglycemia.
  • Plan meals intentionally: During the eating period, intake nutrient-dense foods to ensure proper nutrition and prevent binge eating or snacking.


Intermittent fasting is an effective tool for managing diabetes and preventing its complications. It reduces glucose and lipid levels and increases insulin sensitivity.

The 16:8 approach, 5:2 diet, and eTFR are among the intermittent fasting forms to try. However, people with diabetes first seek their healthcare provider’s approval before starting with it.

Frequently Asked Questions (FAQ)

Is intermittent fasting okay for diabetics?

Yes, scientific data suggests that diabetics could benefit from intermittent fasting by lowering their blood sugar levels and insulin resistance.

Can you reverse diabetes with intermittent fasting?

Yes, intermittent fasting coupled with proper diet and lifestyle changes can reverse prediabetes and type 2 diabetes but not type 1. This does not mean that you will be cured, but you will have normal blood sugar levels.

How many hours should a diabetic fast?

Diabetics can fast for up to 16 hours a day once they get used to it, but fasting for more than that may be dangerous for them. As always, listen to the healthcare provider’s advice for a more personalized approach.

Why is my blood sugar high after fasting for 16 hours?

This may be due to the liver producing more glucose in the bloodstream or the pancreas releasing more glucagon in response to low sugar levels. Reporting this to your healthcare provider is crucial.


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Mag. Stephan Lederer, MSc.

Mag. Stephan Lederer, MSc. is an author and blogger from Austria who writes in-depth content about health and nutrition. His book series on Interval Fasting landed #1 on the bestseller list in the German Amazon marketplace in 15 categories.

Stephan is a true man of science, having earned multiple diplomas and master's degrees in various fields. He has made it his mission to bridge the gap between conventional wisdom and scientific knowledge. He precisely reviews the content and sources of this blog for currency and accuracy.

Click on the links above to visit his author and about me pages.

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