- Intermittent fasting is a diet plan alternating between periods of restricted and unrestricted eating.
- Intermittent fasting can contribute to short-term weight loss, one of the goals for reversing diabetes.
- Speak with your doctor before starting on any diet, especially if blood sugar is a concern.
Weight management is fundamental to the treatment of diabetes, and people with diabetes need to consider any diet carefully. Intermittent fasting eating plans have become popular ways to lose weight that may be valuable for those with diabetes. While intermittent fasting is still in need of large-scale human studies, the evidence is strong that it can be a useful tool to help those with diabetes manage their weight and maybe even reverse diabetes.
What Is Intermittent Fasting?
With an intermittent fasting eating plan, you alternate between fasting periods, where you either eat nothing or severely restrict calories, with eating periods with no food restrictions. There are several intermittent fasting schedules.
Some of the more common include:
- 16/8. Short for 16 hours and 8 hours, on this schedule you fast or restrict for 16 hours, then eat normally for the remaining eight hours a day. This is the most popular plan.
- 5:2. In this pattern, you eat for five days, then fast for two.
- Alternate-day. You eat on one day and fast the next.
In all cases, these are not eat-what-you-want diets, although cheat days may be built into some plans. Instead, most intermittent fasting diets recommend eating a healthy diet during eating periods. The theory behind intermittent fasting is that periods of fasting push the body to burn fat, triggering weight loss.
There is conflicting data on how well this works in overweight but otherwise healthy individuals, but there is a growing body of research that intermittent fasting may have significant benefits for those with diabetes.
Why Intermittent Fasting for Diabetes?
If you have diabetes, you either have difficulty producing insulin or difficulty responding to it, making it difficult to metabolize carbohydrates and causing wild and dangerous swings in your blood sugar. According to the CDC, 11.3 percent of Americans have diabetes, with 90 to 95 percent experiencing type 2 diabetes, which can be managed or even reversed in some circumstances.
Abnormal blood sugar causes atherosclerosis, or stiffening arteries, and the closing down of blood vessels. This causes damage across the body to people with type 2 diabetes, including the blood supply to the penis, causing erectile dysfunction. It also aggravates other issues that can contribute to ED, like heart disease.
Obesity raises the risk of a type II diabetes diagnosis, in part because body weight appears to be a factor in developing insulin resistance. It’s also an indicator of prediabetes, where blood sugar is not high enough to indicate a diagnosis of diabetes, but a future diagnosis may be imminent.
Can Intermittent Fasting Reverse Type 2 Diabetes?
Treating — and potentially reversing — type 2 diabetes starts with lifestyle changes. Most importantly, anybody in prediabetes or just diagnosed with diabetes should focus on quickly and safely losing weight, between 30 and 40 pounds. Researchers believe that by reducing fat around the liver and pancreas, these organs can better distribute and process insulin, decreasing insulin resistance and bolstering pancreatic function.
However, the sooner weight is lost after a diagnosis, the better. And intermittent fasting is quick: In one small-scale study using the 16/8 approach, participants lost approximately three pounds in two weeks. But you may not have to lose weight to see benefits.
Caloric restriction methods such as intermittent fasting have shown promising results with diabetes reversal. A 2019 randomized control trial that restricted its subjects to approximately 800 calories a day before shifting over to a standard weight management plan saw diabetes remission in 46% of participants; 24% of the group in a restricted diet lost 30 pounds or more. Another randomized trial in 2020 found 60% of participants reversed their diabetes diagnosis with calorie restriction.
With intermittent fasting specifically, a small trial run by Chinese doctors found 44% of participants showed evidence of remission a year later. What’s more, half of the intermittent fasting group no longer needed diabetes medication after three months. Another study found that even without weight loss, carefully managed fasting reduced insulin levels while increasing insulin sensitivity.
In theory, intermittent fasting can also help with blood sugar, for the simple reason that if your blood sugar is high and your body can’t get fuel anywhere else, it will burn the sugar. However, current best practices for intermittent fasting and diabetes involve medical supervision and careful blood glucose monitoring to maintain safety, and to break the diet if your blood sugar is dangerously low.
Potential Risks of Intermittent Fasting
Just like any other diet, before starting on an intermittent fasting plan, talk to your doctor. For some people, intermittent fasting isn’t recommended.
You may not be a good candidate for intermittent fasting if you:
- Are pregnant or may become pregnant
- Have been diagnosed with or previously experienced an eating disorder
- Are already on a restricted diet due to gastrointestinal concerns or diseases
- Have to take medication with food at certain times of the day
- Are immunocompromised
- Have been diagnosed with cancer or recovering from it
- Have a nutrient deficiency or eat a specific diet to prevent one
For people with type 2 diabetes, intermittent fasting carries a risk of low blood sugar, so work out a plan with your doctor. Particularly, ask yourself a few questions about your daily schedule:
- What are your current eating patterns, and are they positive or negative for your diabetes treatment?
- How frequently do you experience rapid changes in your blood sugar?
- What are your overall weight management plans and schedule?
Finally, remember that not everyone can stick with intermittent fasting over the long term. If you have difficulty with rigorous schedules or have a life where you’re not sure where and when you’ll need to eat, you should consider another diet plan.
Alternatives to Intermittent Fasting for Diabetes
Fortunately, there are plenty of options for weight management. If intermittent fasting isn’t for you, consider some of the following:
- An alternate eating plan. Work with a dietician who specializes in diabetes, built around your schedule and needs. Eating plans with good supporting evidence for people with diabetes include the Mediterranean diet and the DASH diet. (Bonus: These diets are also excellent for men who suffer from erectile dysfunction!)
- The diabetes plate method. At meals, fill half your plate with vegetables, a quarter with starches, and a quarter with lean proteins.
- The glycemic index. This system ranks foods from zero to 100, with pure glucose being 100. A low-GI diet emphasizes foods with a GI under 55.
- A weight loss device such as Plenity. Plenity fills the stomach with a natural, fiber-like substance that causes you to feel more full and eat less.
Some may even use a combination of these, for example, using the glycemic index to determine which foods to eat during active periods of an intermittent fasting plan.
People With Type 2 Diabetes Don’t Have To Let It Control Them
Intermittent fasting can help you launch your weight management plan, help you get an early handle on your blood sugar, and help decrease your insulin resistance. While diabetes management should be done in collaboration with a doctor, the benefits are worth discussing. It will help you determine the eating plan that best fits in your life.
To learn more about weight loss, with or without diabetes, follow our blog and visit our Plenity weight loss page.
Dan is a long-time freelance writer focusing on technology, science, health, and medicine, with a lifelong interest in physics, biology, and medicine. His work has taken a particular focus on scientific studies “beyond the headlines,” reading the study to more closely examine the results.