Why does intermittent fasting work for type 2 diabetes? – Page 2 – Diabetes Doctor

Why does intermittent fasting work for type 2 diabetes?

Intermittent fasting has gotten a lot of attention recently for its proposed benefits on weight loss and, now, type 2 diabetes.  Many diabetes experts recommend following a low carbohydrate high fat (LCHF) diet. Since fat doesn’t need insulin to metabolize (like carbohydrates and even proteins do), it does not impact blood sugars or cause an insulin surge in the body.  But when calorie restriction, cutting portions and following an LCHF diet just isn’t enough – you may consider talking with your doctor about intermittent fasting. Some people are calling this the “cure for Type 2 Diabetes.”  

What is intermittent fasting?

Fasting means going a certain period of time without eating at all. The most popular methods are:

  • Alternate Day Fasting: A "fast day" of 24 hours is alternated with a day of regular food intake.
  • 5:2 Method: 2 non-consecutive days out of the week are considered "fast days", 5 days of the week are regular food intake.
  • 16:8 Method: All daily calories are eaten within an 8-hour window that you choose, but nothing is eaten the other 16 hours in the day. For example, many people skip breakfast and only eat during an 8-hour window such as 11 a.m. to 7 p.m. This method tends to be the most popular and most successful because it seems to be more manageable for most people than going 24+ hours without eating.  The rules are simple – don’t eat outside of the 8 hour window!

 Intermittent Fasting

During the fasting period, you can drink water, coffee, tea, or bone broth but should restrict total daily calories to < 500.

Much more than restricting calories…

A recent study shows people who followed an alternate-day fasting diet cut weekly calories by an average of 37% and lost an average of 7.7 pounds over four weeks, while those not on the diet reduced calories an average of 8.2% and lost an average of 0.44 pounds.  However, it should be understood that intermittent fasting is different than just cutting calories on a daily basis and has benefits beyond weight loss. 

It would be assumed that intermittent fasting only works because you are restricting the total amount of calories you are eating… although this may help, it is not the only piece of the puzzle. The key here is how often you eat, not the total number of calories you eat. Going long periods without eating at all versus eating a small amount more frequently induces a different metabolic and hormonal response by the body.  

Metabolic response:  Regularly cutting calories cause a decrease in the body’s metabolic rate … to counteract weight loss efforts! So eating less just means your metabolism slows down so it doesn’t burn as many calories – making weight loss quite literally impossible.  Additionally, people are left feeling cold, tired, and hungry.

What about intermittent fasting? “Wouldn’t this make my metabolism go to ZERO?” Actually, no! Some studies show metabolism actually slightly INCREASES during a period of fasting. Other studies show there is no decrease/no change in metabolic rate after 22 days of alternate daily fasting. During fasting, the body first burns off glycogen (i.e. stored sugar) in the liver, and then turns to burn fat. Since there is plenty of fat to burn, the body’s metabolic rate doesn’t drop.  Also, since there is no change in metabolic rate with intermittent fasting, there is also a low risk for rebound weight gain.

 Hormonal changes: Remember that type 2 diabetes is a disease of hyperinsulinemia (i.e. too much insulin!) – so the goal should be to lower insulin levels in the body as much as possible!   Intermittent fasting provides extended periods of low insulin to enhance insulin sensitivity and lowers insulin maximally compared to any other diet. 

Studies show that you may be able to lose the same amount of weight with intermittent fasting as restricting calories … but intermittent fasting is more effective at reducing insulin levels, reversing diabetes, and reducing the amount of fat inside the liver and pancreas organs. You can’t have a constant intake of food to get this same effect – despite decreasing carbs and calories.

With intermittent fasting, insulin levels drop sharply, noradrenaline rises to keep metabolism high, and growth hormone rises to maintain lean muscle mass. Recent studies also show a reduction in inflammation levels.

How long does it take to work?

Weight loss can start to occur quickly in the first few days.  If you are looking for diabetes remission and reduction in medications - usually people see results within weeks, but keep in mind it could take several months depending on the intensity of the fasting regimen and length of time you have had diabetes.

What do I eat during non-fasting periods?

Keep in mind, the more you eat insulin stimulating food (carbs/sugar/processed foods), the more you need to fast to bring those insulin levels back down. So it is recommended to follow LCHF during non-fasting times for maximum benefits.  In other words – you can’t binge for 8 hours and expect great results!

How should I expect to feel?

As the body starts to eliminate its stored sources of sugar (in the blood and organs) – people may experience initial hunger pains, headaches, and muscle cramping as it “detoxes”.  As insulin levels drop, this triggers the liver to release stored sugar and some people may notice an initial rise in blood sugar levels as this happens. Remember if the sugar is not coming from food, it is coming from somewhere else in the body (i.e. shifting locations to the blood!) and generally means a longer fast is needed (such as more hours fasting or more frequent days fasting).  If you aren’t replenishing the liver with sugar in between fasts, over time the stored sugar sources should eventually deplete themselves.

What do I do with my medications?

Fasting for a person with diabetes can be potentially dangerous and requires medical supervision.  You must talk with your healthcare provider for guidance with medication adjustments.  Risk of hypoglycemia with certain medications can be extremely dangerous (especially with insulin and sulfonylureas like glipizide and glimepiride) and certain medications such as SGLT2 inhibitors (Invokana, Farxiga, Jardiance, Steglatro) should absolutely not be taken during long fasting periods. 

How can Diabetes Doctor™ products help?

It is recommended to use Daily Support and Sugar-Blocker for support during intermittent fasting regimens.  Daily Support™ reduces insulin resistance, which helps reduce insulin levels.  Sugar-Blocker can be taken with meals on non-fasting days to reduce the number of carbohydrates absorbed with food. It can also be taken during fasting periods to suppress sugar cravings. Berberine, the key ingredient in Sugar-Blocker, is a powerful insulin sensitizer and has been shown to lower insulin levels.  


  • Andre Harris

    Do I still Need to take my Metformin while (a) fasting and (b) taking this “medicine”?

  • Monica

    Hi there!
    I plan to purchase all 3 of the products. My question is, should I take these products on fasting days? I can’t see why not, but just double checking

  • Dr. Stephanie Redmond

    Hi Kathy! Thanks for your question. Please do always check with your doctor before starting a new plan like this. Yes, many people do this every single day. Generally, doctors will recommend that you only take medications like Jardiance when you are eating (not during the fasting period). Healthline has a nice article about the 16/8 method specifically. Check out more information here: https://www.healthline.com/nutrition/16-8-intermittent-fasting#getting-started. Let us know if you have any feedback on your experience with it! Would love to hear some follow-up.

  • Kathy McDowell

    I am very interested in doing the 16:8 method. I am on victzo, metformin and jardance. I am planning to discuss this with my Dr on my next appointment… Sept 17th 2019. Is there any other information you can give me? Do you do the 16:8 method every day? Thank you for posting this I had never heard of it before.
    Sincerely Kathy McDowell

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