Potential Benefit Of Intermittent Fasting For Diabetes: It May Boost Weight Loss
In previous years, dietitians and scientists thought of IF as a negative practice, so there isnt a wealth of high-quality clinical research on how it may affect people with diabetes, says Jason Fung, MD, a nephrologist in Toronto and coauthor of The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting. But attitudes have begun to change, and some newer studies suggest the approach may have benefits, including for people with diabetes.
For example, a small study published in August 2021 in the journal Hormone and Metabolic Research found that IF lowered insulin resistance in 13 adults with type 2 diabetes. Insulin is a hormone that helps shuttle glucose out of the bloodstream people with type 2 diabetes are resistant to insulin, which results in higher blood sugar levels.
Its thought that losing weight through IF can lead to improvements in insulin sensitivity, too, says Michael Mosley, MD, a science journalist and coauthor of The FastDiet.
In addition, a review of existing research published in February 2021 in the journal Clinical Diabetes and Endocrinology included several studies that found IF reduced fasting glucose levels, weight, and post-meal blood sugar levels in people with type 2 diabetes. Even with these studies, though, further research needs to be conducted to see whether IF is truly safe for people with type 2 diabetes as a whole, experts say.
Prescribing Intermittent Fasting In Practice: Recommendations
While alternate day fasting and periodic fasting have demonstrated efficacy in improving metabolic risk factors, it may be difficult to convince patients to give up or severely restrict calories for an entire 24h period. In America, we often eat 3 meals per day in addition to frequent snacking. Furthermore, in American culture most social engagements involve food. Asking patients to eliminate these experiences from their day to day lives may become burdensome, and thus hinder patient compliance. Finally, patients switching to an intermittent fasting regimen may initially experience symptoms such as hunger and irritability, although these symptoms often dissipate within the first 30days . Therefore, it would be more appropriate to gradually introduce intermittent fasting in the form of time restricted feeding. For example, clinicians may first recommend that patients restrict their intake to a daily 12h period, typically an overnight fast . As patients become more comfortable with this pattern of eating, the feeding window can be restricted further . This allows the patient some daily flexibility in choosing when to consume calories, thus increasing the likelihood of compliance. Lastly, patients who have become adapted to time restricted feeding may choose to switch to alternate day or periodic fasting with the supervision and guidance of a registered dietician. See Fig. for a detailed example of an intermittent fasting prescription.
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Intermittent Fasting And Insulin Sensitivity
Insulin plays a significant role in glucose homeostasis due to its influence in promoting the storage and utilization of glucose. However, the effects of insulin are not limited to glucose homeostasis. Insulin also plays a role in the stimulation of DNA synthesis, RNA synthesis, cell growth and differentiation, amino acid influx, protein synthesis, inhibition of protein degradation, and most importantly, the stimulation of lipogenesis and inhibition of lipolysis .
It is the development of insulin resistance, which is defined as the necessity of higher circulating insulin levels in order to produce a glucose lowering response, that is thought to be responsible for the development of type 2 diabetes . In order to promote regulation of glucose homeostasis, insulin works primarily on receptors in skeletal muscle, liver, and white adipose tissue . In short, there are several proposed mechanisms regarding the development of insulin resistance. One of the more prominent theories describes the association of increased adiposity and the subsequent chronic inflammation that leads to the development of insulin resistance in tissues .
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History Of Diabetes And Intermittent Fasting
Fasting has been around for a long time. It’s been a historical part of some spiritual traditions stretching back centuries. More recently, IF has been used as part of a healthy diet for weight loss, as a “detoxifying” strategy, and more.
There’s been some debate about whether fasting is healthy for those with diabetes. A growing body of evidence suggests that some IF diets could benefit people with diabetes. Scientists note that when a person fasts may be just as important as the diet itself.
To Skip Or Not To Skip: Does Intermittent Fasting Help People With Diabetes
Weve reviewed the latest research to weigh the benefits and drawbacks of intermittent fasting and time-restricted feeding for people with diabetes.
Living with diabetes means carefully making sure you are eating foods that will keep your blood sugar and insulin levels in balance. However, a recent trend in the diabetes community focuses on when to eat. You may have heard friends, family, and healthcare professionals use words like intermittent fasting and time-restricted feeding to describe this trend. We are going to take a closer look at what these eating strategies entail, how they might affect people with diabetes, and the risks and benefits to consider if you choose to skip a meal.
Intermittent fasting refers to a style of eating in which you alternate through a pattern of consuming little to no calories for a while and a normal eating schedule. Popular IF schedules include alternate day fasting, where one day you consume very little food and the next day you eat like you normally would this regimen is usually repeated every other day, though some people make exceptions to this depending on what works best for their lifestyle. Another method is periodic fasting , where you reduce your food consumption on certain days of the week but then eat regularly on the other days. These patterns aim to reduce the number of calories you are consuming.
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Intermittent Fasting May Help People With Type 2 Diabetes Control Blood Sugar
Intermittent fasting might help people with Type 2 diabetes better control their blood sugar levels, a new study has found.
People with diabetes who restricted their eating to within a daily 10-hour window wound up with blood sugar levels in the normal range for about three hours longer than when they ate whenever they pleased, the researchers reported.
These patients also experienced lower 24-hour blood sugar levels and consistently lower morning fasting glucose when they participated in a time-restricted eating pattern, the investigators found.
“Time-restricted eating may be an effective approach to improving metabolic health in adults with Type 2 diabetes, but more studies are needed to confirm this finding,” said lead researcher Charlotte Andriessen, a doctoral student in the department of nutrition and movement sciences at Maastricht University in the Netherlands.
This study answers a question that’s on the minds of many people trying to manage their diabetes, said Dr. Reshmi Srinath, director of the Mount Sinai weight and metabolism management program in New York City.
“There is a lot of interest in intermittent fasting, both in our patients with diabetes and with obesity, looking to help their metabolic health and to help them lose weight,” Srinath said. “So this is actually a really key study that’s relevant to us in real time.”
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Reduction Of Glucose Levels
The glucose levels of the blood are a significant differentiating factor in an individual with diabetes and without diabetes. Since Diabetes Mellitus is associated with higher levels of glucose in the body, even in fasting states, it can lead to serious health problems like damage to the blood vessels, damage to vital organs, and development of cardiac conditions. However, intermittent fasting is found to be effective in diabetic and pre-diabetic individuals by lowering the fasting blood glucose by almost 4mg/dL.
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Does Research Suggest That If Improves Markers Of Health In Humans
The majority of IF research has involved animals rather than human participants. The evidence to support health improvements in people is promising, but many of the clinical studies to date have been relatively short-term interventions over a period of months.
A 2018 review article showed that nearly all IF studies resulted in some degree of weight loss, ranging from , and associated fat mass loss. However, there is little research to prove that IF is superior to other diets and eating patterns in promoting weight loss.
The use of an IF diet may also have a beneficial effect on blood pressure. In one , researchers observed 1,422 people for 1 year while they followed a fasting program. The participants experienced a reduction in both systolic and diastolic blood pressure.
In another study , which involved adult males, researchers found that IF provided metabolic and cardiovascular benefits, such as a decrease in total cholesterol and low-density lipoprotein cholesterol.
Scientists know that insulin resistance improves with calorie restriction. After a period of fasting, insulin sensitivity increases, and insulin levels decrease. These changes result in improved blood sugar levels both during fasting and shortly after eating.
IF can have various health benefits for people with diabetes. These include:
- promoting weight loss
- improving insulin sensitivity, leading to lower insulin requirements
- normalizing fasting blood glucose levels
- reducing hemoglobin A1c levels
Can I Do Intermittent Fasting While On Metformin
According to the National Institute of Diabetes and Digestive and Kidney Diseases , intermittent fasting is safe if you take a diabetes medication like metformin. However, it depends on the length of time you intend to fast for that day.
For instance, those who fast for 16 hours and eat for the other 8 hours dont really need to stop metformin, as it rarely can cause hypoglycemia. The medicine should be in their system for those 6-8 hours while eating, preventing hyperglycemia.
On the other hand, you shouldn’t take metformin on the day of intermittent fasting if you intend to fast for the full 24 hours, as it can increase the risks of hypoglycemia.
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Effect On Other Health Conditions
The effect of intermittent fasting for those with other health conditions is unknown. This includes those with established coronary artery disease, especially those who have had a heart attack, stroke or TIA . The effects are also unkown for those with unstable angina, heart failure, atrial fibrillation, most cancers, those who are immunosuppressed, have chronic obstructive airways disease, blood clots, and chronic kidney disease.
Pregnant and breastfeeding women, children, frail and older adults should not engage in intermittent fasting. Those with dementia or who have an eating disorder are best not to follow an intermittent fasting regimen.
Can You Fast If You Have Diabetes
Yes in some circumstances, but it depends on how healthy you are.
Ultimately, it is a personal choice whether or not to fast. However, if you do choose to fast, then you must consult your doctor or healthcare team, to make sure that you are able to look after yourself properly. We’ve got lots more information about fasting and how to do it safely.
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Benefits Of Intermittent Fasting
A few small studies have shown that intermittent fasting can have health benefits for people with diabetes.
The benefits include:
- Dehydration
- Daytime sleepiness
- Low energy levels that may impact your ability to exercise, which is important for people with diabetes
- A much higher risk of low blood sugar
- High blood sugar which can happen if the liver responds to fasting by releasing stored glucose
More research is needed to understand how common and how severe these side effects could be.
Some side effects, like hyperglycemia or hypoglycemia, could be dangerous for people with diabetes. Talk to your healthcare provider before you start any type of IF diet.
Staying Well While Fasting
If you decide to fast, it is important to test your blood glucose levels more often as your blood sugar levels after fasting eight hours may drop too low . This is more likely to happen if you are unwell, treat your diabetes with insulin or some diabetes medications, or both. Speak to your diabetes team about this.
If you experience the symptoms of a hypo, such as feeling shaky, sweaty and disorientated, you must break the fast immediately and treat it with your usual hypo treatment, like glucose tablets, a sugary drink or GlucoGel, followed by a snack such as a sandwich or a bowl of cereal.
If you have to break your fast for any reason, continue your meals as normal for that day. You may be able to make up the fast at a later date or provide meals to the needy.
If you have type 1 diabetes, there is also a danger that your blood glucose levels may run too high and result in a build-up of ‘ketones’. This could potentially result in a serious condition known as ketoacidosis. The symptoms of high blood glucose levels might include feeling very thirsty, passing a lot of urine or extreme tiredness. If your blood glucose levels stay high and you experience these symptoms, speak to your healthcare team.
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Can Intermittent Fasting Cause Diabetes
Although IF can help with type 1 and 2 diabetes in many cases, there’s also a concern that the diet might cause diabetes in prediabetic or otherwise healthy people. Continuous fasting can potentially damage insulin, increasing the dieter’s risk of developing diabetes.
As type 2 has become an epidemic over the past couple of years, this could be detrimental. The University of Sao Paulo in Brazil conducted an animal study evaluating the potential risks of intermittent fasting on rats over three months. Although weight loss occurred, long-term IF may damage the pancreas and affect insulin function in healthy individuals.
Although immediate results can be beneficial for the prevention and treatment of type 1 and 2 due to the reduction in body mass index, there is still a concern for the long-term effects that researchers have not studied as thoroughly.
Its important to note that this is a single study conducted on rats and not humans. We need more research to understand if there is any link between IF and diabetes in humans and whether long-term intermittent fasting is safe for those with diabetes. Discuss IF with your primary care doctor or diabetic team before starting the diet to ensure it’s safe for you to participate.
Is Intermittent Fasting Safe For People With Type 1 Diabetes
Many people with type 1 diabetes have found that IF and TRF can help reduce morning blood sugar fluctuations and improve their energy. An observational study on people with type 1 diabetes who participated in various forms of IF/TRF found that these eating schedules can be safe as long as the individual works with their healthcare professional to reduce their usual insulin dose while fasting, and they must monitor their glucose levels carefully to avoid hypoglycemia. Fasting will also increase your ketone levels, so it is important to test your blood ketone levels if you have type 1 diabetes to avoid the risk of ketoacidosis. Remember that people with type 1 diabetes absolutely require insulin to avoid DKA, so insulin dose adjustment to avoid low glucose levels must be done cautiously.
For anyone with diabetes, before trying any type of fasting you should talk to your healthcare professional. For people who take sulfonylureas or insulin, it is important to closely monitor blood sugar levels, especially when you first start a fasting regimen, as dose reductions may be necessary to avoid hypoglycemia. Never stop taking a medication or change its dosage without consulting your healthcare professional first.
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Why Might Changing Timing Help
But why does simply changing the timing of our meals to allow for fasting make a difference in our body? An in-depth review of the science of IF recently published in New England Journal of Medicine sheds some light. Fasting is evolutionarily embedded within our physiology, triggering several essential cellular functions. Flipping the switch from a fed to fasting state does more than help us burn calories and lose weight. The researchers combed through dozens of animal and human studies to explain how simple fasting improves metabolism, lowers blood sugar levels lessens inflammation, which improves a range of health issues from arthritic pain to asthma and even helps clear out toxins and damaged cells, which lowers risk for cancer and enhances brain function.
How Does Intermittent Fasting Work With Type 2 Diabetes
According to an academic review,² 24-hour fasting regimens significantly reduced weight and blood glucose in people with diabetes. These diets also led to some patients stopping insulin therapy as their blood sugar was under control.
Researchers noted that people might struggle with fasting for 24 hours or more. Therefore, they may be better off starting with shorter intervals and time-restricted feeding. They recommended this IF prescription:
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In week one, fast for 12 hours and feed for 12 hours. Stick with this fasting period until you’re comfortable moving to the next phase. The researchers recommend monitoring and logging your daily blood glucose levels so you can send them to your doctor weekly.
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Typically starting in week five, you fast for 16 hours and feed for eight hours. The next phase is to increase your fasting period by four hours when you’re ready. The report says that you should continue monitoring and logging blood sugar levels. You should also consult a registered dietician to discuss food intake and ensure you’re dieting responsibly.
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Typically starting in week seven, you fast for 18-20 hours and feed for 4-6 hours. Finally, when you’re ready to continue to the next step of the IF process, it is time to add 2-4 more hours to your fasting routine. At this time, the report notes that your doctor should adjust your diabetes medication dosages based on your logged blood sugar readings.
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