Intermittent Fasting and Type 2 Diabetes: Understanding the Impact on Insulin Sensitivity and Glycemic Control

Intermittent fasting is a pattern of eating that alternates between periods of eating (referred to as 'feeding windows') and periods of fasting (not eating). It's not so much about what you eat, but rather when you eat. Contrary to what the name might suggest, it's not about starving yourself but instead involves strategically scheduling your meals to make the most of your body's natural metabolic rhythms. In this article, we discuss the impact this eating pattern can have on people with type 2 diabetes.

Types of Intermittent Fasting Diets 

There are various types of intermittent fasting diets that people with diabetes may consider. Each one has different fasting and eating windows, offering different degrees of flexibility. Here are five common types:

  • 16/8 Method: This method involves fasting for 16 hours each day and eating all meals within an 8-hour window. It's one of the most popular forms of IF due to its flexibility and simplicity.
  • 5:2 Diet: In this approach, individuals limit their calorie intake to 500-600 calories for two non-consecutive days of the week and eat a normal diet the other five days.
  • Eat-Stop-Eat: This diet involves a 24-hour fast once or twice a week. During non-fasting days, there are no restrictions on food intake.
  • Alternate-Day Fasting: In this form of IF, you alternate between days of normal eating and days where you either completely fast or consume a very limited amount of calories (around 500 calories).
  • Warrior Diet: This diet involves consuming small amounts of raw fruits and vegetables during the day and having one large meal at night, essentially fasting for 20 hours and eating within a 4-hour window.
  • OMAD (One Meal a Day): As the name suggests, this method involves eating only one meal a day, usually within a one-hour eating window, and fasting for the remaining 23 hours. This is a more extreme version of intermittent fasting and may not be suitable for everyone, especially those with specific health conditions or nutritional needs.

Benefits of Intermittent Fasting for Type 2 Diabetes

Intermittent fasting has the potential to benefit individuals with type 2 diabetes in various ways. Below, we dive into the science behind the benefits of IF for diabetes management.

Improved Blood Sugar Control

One of the primary goals in managing type 2 diabetes is maintaining stable blood sugar levels. Surprisingly, fasting, despite involving periods without food, may contribute to better blood sugar control.

When you consume food, your body breaks it down into various components, including glucose, which enters your bloodstream and raises your blood sugar levels. In response, the pancreas releases insulin, which allows your cells to absorb glucose and use it for energy. However, in type 2 diabetes, this process doesn't work effectively, resulting in high blood sugar levels.

Intermittent fasting can help enhance this process. By restricting eating to specific windows, it allows for extended periods where the body isn't processing food and the pancreas isn't releasing insulin. This break gives the body time to use up its glucose reserves and lowers insulin levels. Then, when you eat again, your body should be better able to process glucose, leading to better blood sugar control.

Improved Insulin Sensitivity

Insulin is a hormone that is released by the pancreas in response to elevated blood glucose levels, typically after a meal. This hormone binds to insulin receptors on the surface of cells, mainly in the liver, muscle, and fat tissues, allowing glucose to be absorbed from the bloodstream and used for energy. This is the body's normal response to keep blood sugar levels in check.

In people with type 2 diabetes, cells become resistant to insulin's effects, a condition known as insulin resistance. This leads to less glucose being absorbed by cells and an excess remaining in the bloodstream, resulting in high blood sugar levels. Over time, the pancreas attempts to compensate by producing more insulin, leading to a state of hyperinsulinemia, or excess insulin in the blood.

During the fasting period, the intake of food, and thereby glucose, is reduced. As a result, blood glucose levels drop, and the need for insulin decreases. The pancreas gets a much-needed break and does not need to release as much insulin.

With consistent periods of lower insulin levels during fasting, cells can gradually regain their sensitivity to insulin. This 'reset' can help them respond better to insulin when it's released during the eating periods, allowing more effective glucose absorption and lower blood sugar levels.

Reduced Inflammation

Chronic inflammation is common in individuals with type 2 diabetes. It's associated with insulin resistance and can increase the risk of other health complications, including heart disease.

Intermittent fasting has been found to reduce inflammation. During the fasting periods, the body goes into a state called 'autophagy' where it starts cleaning up damaged cells, a process which can help lower inflammation. By curbing the inflammatory response, IF can potentially alleviate some of the complications associated with diabetes.

Weight Management

Overweight and obesity are significant risk factors for type 2 diabetes. Losing weight can help manage or even prevent the disease by improving insulin resistance.

Intermittent fasting can support weight loss and management in a couple of ways. Firstly, limiting the window during which one can eat, naturally reduces the overall calorie intake. Secondly, during fasting periods, the body shifts its energy source from glucose to stored fats. This metabolic shift can promote fat burning and lead to weight loss.

Tips for Intermittent Fasting When You Have Type 2 Diabetes

  • Monitor Your Blood Sugar Levels: Regularly check your blood glucose levels during the fasting and eating periods to understand how IF affects your body.
  • Start Slow: Gradually increase your fasting periods. Begin by pushing your breakfast a few hours later, and slowly extend the fasting window.
  • Stay Hydrated: During fasting windows, ensure you're drinking plenty of water or other calorie-free fluids to stay hydrated.
  • Use Technology for Assistance: Apps like Klinio can help track your meals, fasting periods, blood glucose levels, and other health data. This can provide valuable insights and keep you accountable.
  • Consult Your Healthcare Provider: Before starting IF, especially if you are on medication, discuss it with your healthcare provider. They can guide you on safely adjusting your diet and medication.


As we have seen, Intermittent fasting can be helpful for you if you are suffering from type 2 diabetes. But you must approach it with caution as fasting can lead to fluctuations in blood sugar level which could be problematic. Before starting on IF, it's essential to seek guidance from your doctor. They can help you develop a safe and sustainable approach to IF while taking your diabetes medication into account.