Intermittent Fasting: The Key to Regulating Blood Sugar Levels and Managing Type 2 Diabetes

Dr Isaac Eliaz

October 30, 2023

If you have type 2 diabetes or prediabetes, the holiday season can be especially tricky to navigate. So, instead of indulging in sugar- and carb-laden foods this year, treat yourself to healthier blood sugar balance with intermittent fasting.  

Researchers have found that intermittent fasting can be just as successful for weight loss for type 2 diabetics as reducing calorie consumption by 25%.  

According to the study in JAMA Network Open, people engaging in time-restricted eating for type 2 diabetes had an easier time losing weight compared to those told to simply cut calories.  

Moreover, participants who restricted their eating between noon to 8 p.m. lost more weight in six months than those who simply cut back on calories. Both groups experienced a drop in their haemoglobin A1C test results, an average of blood sugar levels over the last three months.1  

Understanding Intermittent Fasting  

Intermittent fasting is a lifestyle that involves cycling between periods of eating and fasting. There are several different ways to practice intermittent fasting, but the most common methods include the 16/8 method, where you fast for 16 hours and eat within an 8-hour window, and the 5:2 method, where you eat normally for five days and restrict calories to 500–600 on two non-consecutive days.  

What makes intermittent fasting effective for diabetes management is that it helps to regulate blood sugar levels. When we eat, our bodies break down the food into glucose, which is then used for energy. Insulin, a hormone produced by the pancreas, helps to transport glucose from the bloodstream to the cells where it can be used for energy. However, in individuals with type 2 diabetes, the body becomes resistant to insulin, and glucose builds up in the bloodstream, leading to high blood sugar levels. Intermittent fasting can help to reduce insulin resistance, which in turn can lead to better blood sugar control and improved diabetes management.  

How Intermittent Fasting Affects Blood Sugar Levels  

Intermittent fasting can have several positive effects on blood sugar levels. For one, it can reduce insulin resistance, which is a key factor in type 2 diabetes. When we fast, our bodies need to find alternative sources of energy, and one of the ways it does this is by breaking down stored glucose in the liver. This process, known as glycogenolysis, releases glucose into the bloodstream, which can be used for energy.  

Additionally, fasting can trigger a process called autophagy, where the body breaks down damaged cells and tissues. This can help to reduce inflammation, which is another factor that contributes to insulin resistance and type 2 diabetes. By reducing inflammation, the body can become more sensitive to insulin, which can lead to better blood sugar control.  

The Link Between Intermittent Fasting and Managing Type 2 Diabetes  

In addition to the study mentioned above, earlier research has shown that intermittent fasting can have a significant impact on managing type 2 diabetes. In one study, participants who practiced intermittent fasting had lower A1C levels (a measure of blood sugar control over time) than those who followed a standard diet.2 Another study found that intermittent fasting led to significant weight loss, which is important for diabetes management, as excess weight can contribute to insulin resistance.3  

Intermittent fasting has also been shown to improve other markers of health, such as cholesterol levels, blood pressure, and inflammation. By improving these factors, individuals with type 2 diabetes can reduce their risk of developing complications such as heart disease, stroke and kidney damage.4  

Benefits of Intermittent Fasting for Overall Health  

While intermittent fasting is often associated with diabetes management, it has a range of health benefits. For one, it can lead to weight loss, which can improve cardiovascular health and reduce the risk of chronic diseases such as cancer and Alzheimer’s.5  

Intermittent fasting has also been shown to improve brain function, as it promotes the growth of new brain cells and increases the production of a protein called brain-derived neurotrophic factor (BDNF), which is important for learning and memory. Additionally, fasting can reduce oxidative stress, which is a key factor in ageing and age-related diseases.6  

It’s important to note that intermittent fasting may not be suitable for everyone, especially those with certain medical conditions or who are pregnant or breastfeeding. It’s always a good idea to consult with a healthcare professional before starting any new diet or lifestyle.  

Tips for Getting Started with Intermittent Fasting  

If you’re interested in trying intermittent fasting, here are some tips to help you get started:  

  • Start slowly: don’t jump into a 16-hour fast right away. Instead, start with a 12-hour fast and gradually increase the fasting window over time — customise the fast to fit your tolerance and lifestyle. 
  • Stay hydrated: drink plenty of water and other non-caloric beverages during the fasting period to stay hydrated.
  • Listen to your body: If you feel dizzy, lightheaded, or nauseous, break your fast and eat something.
  • Be flexible: if you have a special occasion or event coming up, it’s okay to break your fast for that day. Just resume your fasting schedule the next day.


Combining Intermittent Fasting with a Healthy Diet for Optimal Results  

While intermittent fasting can provide many benefits on its own, combining it with a healthy diet can lead to even better results. Here are some tips for combining intermittent fasting with a healthy diet:  

  • Choose whole, nutrient-dense foods: Focus on lean proteins, vegetables, fruits, and whole grains. Avoid processed foods, sugary drinks, and high-fat foods.  
  • Don’t overeat during the eating window: Just because you’re fasting doesn’t mean you can eat whatever you want during the eating window. Stick to normal portion sizes and make healthy choices.  
  • Consider a low-carb or ketogenic diet: These diets have been shown to improve blood sugar control and may be particularly beneficial for individuals with type 2 diabetes.  


Intermittent Fasting and Exercise for Managing Type 2 Diabetes  

Exercise is an important component of managing type 2 diabetes, and it can be even more effective when combined with intermittent fasting. One study found that combining intermittent fasting with exercise led to greater improvements in blood sugar control and weight loss than either intervention alone.  

When exercising during a fast, it’s important to listen to your body and not push yourself too hard. Start with low-intensity exercise such as walking or yoga, and gradually increase the intensity as you become more comfortable. It’s also important to stay hydrated and replenish electrolytes during and after exercise.  

Common Misconceptions About Intermittent Fasting and Diabetes  

There are several misconceptions surrounding intermittent fasting and diabetes. Here are some of the most common:  

  • Intermittent fasting is a cure for diabetes: while intermittent fasting can help to improve blood sugar control and manage type 2 diabetes, it is not a cure for the disease.  
  • Fasting will cause hypoglycaemia: while fasting can cause a drop in blood sugar levels, it is unlikely to cause hypoglycaemia in individuals with type 2 diabetes who are not taking insulin or certain medications.  
  • Fasting is dangerous for individuals with diabetes: while fasting may not be suitable for everyone with diabetes, it can be safe and effective when done under the guidance of a healthcare professional.  


Intermittent fasting is a lifestyle that has gained popularity in recent years — and for good reason. Research shows it can significantly affect regulating blood sugar levels and managing type 2 diabetes. Additionally, intermittent fasting has a range of benefits for overall health, including weight loss, improved brain function and reduced inflammation.  

  1. Pavlou V, Cienfuegos S, Lin S, et al. Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial. JAMA Network Open. 2023 Oct 2;6(10):e2339337. doi: 10.1001/jamanetworkopen.2023.39337. PMID: 37889487; PMCID: PMC10611992. 
  2. Sharayah Carter, BND, Peter M. Clinton, MD, PhD, Jennifer B. Keogh, PhD. Effect of Intermittent Compared With Continuous Energy Restricted Diet on Glycemic Control in Patients With Type 2 Diabetes: A Randomized Noninferiority Trial. JAMA Network Open. July 2018;1(3): e180756. doi:10.1001/jamanetworkopen.2018.0756 
  3. Welton S, Minty R, O’Driscoll T, et al. Intermittent fasting and weight loss: Systematic review. Can Fam Physician. 2020 Feb;66(2):117-125. PMID: 32060194; PMCID: PMC7021351.  
  4. Allaf M, Elghazaly H, Mohamed OG, et al. Intermittent fasting for the prevention of cardiovascular disease. Cochrane Database Syst Rev. 2021 Jan 29;1(1):CD013496. doi: 10.1002/14651858.CD013496.pub2. PMID: 33512717; PMCID: PMC8092432. 
  5. Elias A, Padinjakara N, Lautenschlager NT. Effects of intermittent fasting on cognitive health and Alzheimer’s disease. Nutr Rev. 2023 Aug 10;81(9):1225-1233. doi: 10.1093/nutrit/nuad021. PMID: 37043764; PMCID: PMC10413426. 
  6. Albrahim T, Alangry R, Alotaibi R, et al. Effects of Regular Exercise and Intermittent Fasting on Neurotransmitters, Inflammation, Oxidative Stress, and Brain-Derived Neurotrophic Factor in Cortex of Ovariectomized Rats. Nutrients. 2023 Oct 6;15(19):4270. doi: 10.3390/nu15194270. PMID: 37836554; PMCID: PMC10574130.

 

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