Intermittent fasting is one of the popular dietary patterns that many people follow in the modern world. Intermittent fasting is gaining popularity worldwide due to its weight loss effects.

It restricts your mealtimes to a specific window, followed by a set amount of time where you eat very little or nothing. A few hours to several days can pass during the fasting phase.

Limiting the amount of time you eat is a component of the intermittent fasting (IF) eating strategy. There are numerous options for how to accomplish that.

For example, some intermittent fasting diets restrict eating between particular hours of the day. Others restrict their caloric intake when fasting. Additionally, some people alternate between fasting days and regular days.

It is no surprise that our eating patterns impact our blood glucose levels. So when you are fasting, the glucose levels tend to drop, and they spike up when you consume food. However, the impact differs for different people. Hence, experts believe intermittent fasting is not suitable for everyone, and people should focus on balanced eating.

One of the reasons is that intermittent fasting can significantly lower glucose levels in some individuals, negatively affecting their health. At the same time, some people experience sudden glucose spikes after consuming foods, which can also be harmful. Hence, nutritionists always focus on a balanced diet with regular meals and healthy nutrients.

Understanding the immediate effects of a diet on your body can be challenging. Sometimes, we do not realise that a dietary pattern negatively affects us before it gets severe. However, HealthifyPro 2.0 can help.

With its Continuous Glucose Monitor (CGM) device attached to your arm, you get real-time information about your glucose fluctuations after a meal or fasting. The Pro coaches assess your readings and see. They also evaluate your patterns and suggest lifestyle changes that you should incorporate to achieve your health goals. As a result, you are more informed about your health, and this can help you implement new healthier habits to improve your overall health.

Types of Intermittent Fasting

You can broadly classify Intermittent Fasting into two types: periodic fasting (PF) and time-restricted feeding (TRF). There are also fasting-mimicking diets (FMD), in which you eat particular foods that mimic the effects of fasting on your body.

Periodic Fasting (PF)

It is a standard fast, during which you forego most of your daily intake of food and beverages. E.g. Religious fasting, the 5:2 diet and Eat Stop Eat. However, popular periodic fasting techniques for diabetes or weight loss frequently utilise a modified kind of fasting instead of a pure fast.

Time-Restricted Feeding (TRF)

Exactly as it sounds, time-restricted feeding limits the daily window for eating to 12 hours or less. For example, you can choose to eat between 7 a.m. and 5 p.m. (a 14:10 schedule, which means 14 hours of fasting and 10 hours of eating) or 8 a.m. and 4 p.m. (a 16:8 schedule). A popular plan is the 16:8 method, which requires a person to fast for 16 hours and eat during an 8-hour window.

Fasting-mimicking Diets(FMD)

The purpose of fasting-mimicking diets (FMDs) is to mimic the effects of fasting by prescribing specific foods and liquids in small amounts.

Intermittent Fasting and Glucose Levels: The Association

Insulin Resistance

According to a study, intermittent fasting is an effective therapeutic option for anyone with impaired glucose and lipid metabolism. It may improve glucose and lipid metabolism, achieve significant weight loss, and improve insulin resistance.

Cells in the liver, fat, and muscle can occasionally react abnormally to insulin. Due to its inability to penetrate cells, glucose accumulates in circulation. Insulin resistance is what causes this. The cells resist the action of insulin. 

In response, the pancreas produces more insulin. Until the pancreas can no longer produce enough insulin to overcome the cells’ insulin resistance, the additional insulin may keep the blood sugar level within a healthy range.


Prediabetes” refers to blood glucose levels higher than normal but not high enough to be classified as diabetes. Insulin resistance is a sign that you might have prediabetes. Additionally, prediabetes might develop if your pancreas cannot produce enough insulin to maintain a normal blood sugar level.

The primary hormone our bodies employ to control blood sugar levels is insulin. Glycemic control, commonly known as maintaining constant blood sugar levels, is a crucial objective for people with diabetes and is frequently assessed using the Time in Range, A1C, and fasting glucose levels.

Getting insulin levels as low as possible for your body to burn stored fat for energy instead of sugar is the main objective of intermittent fasting for weight loss.

In a study of males with prediabetes, early morning TRF reduced insulin fluctuations, improved insulin resistance, and decreased insulin levels (persistently high insulin levels can lead to obesity, heart disease, and other conditions). It increases insulin production and sensitivity.

Intermittent Fasting Mechanism

Here’s how it operates:

  • Food that you eat converts into molecules in your bloodstream by your body. Glucose is one such chemical. It results from the breaking down of carbs.
  • The body produces insulin so that the cells can store and utilise glucose. When blood glucose levels are higher than the body can use, the body stores the excess as fat for later use.
  • Insulin levels can fall when you don’t consume meals or snacks. Low levels of insulin cause fat cells to release part of their stored fat so the body can use it as fuel. Weight loss follows from that.

The HealthifyMe Note

Understanding how your body uses insulin and glucose is beneficial. The hormone insulin makes it possible for glucose (sugar) to reach the muscle, fat, and liver cells used as fuel. Usually, the pancreas releases insulin when blood sugar levels rise. However, insulin reduces blood sugar by “unlocking” cells to allow them to absorb sugar from the bloodstream. Our body does this to maintain a healthy level of blood sugar.

Health Benefits of Intermittent Fasting

Weight loss

Intermittent fasting is more effective at burning fat and shedding pounds than low-calorie diets or other diet plans. Over time, extra fat in the pancreas and liver also burn, which helps with their healthy operation.

Hemoglobin A1C (HbA1C), a measure of blood sugar levels over the previous three months and a sign of either diabetes or pre-diabetes, is decreased by weight loss.

Weight loss results in lower blood pressure. People who regularly fast have lower levels of bad (LDL) cholesterol and higher levels of good cholesterol. It, in turn, lowers the chance of having a heart attack or stroke.

Insulin Sensitivity

Intermittent fasting improves insulin sensitivity in obese and healthy persons by reducing visceral fat. In addition, intermittent fasting lessens glycemic variability or the day-to-day fasting changes in blood sugar levels. Intermittent fasters also exhibit lower fasting and post-meal blood sugar levels.

Metabolic Switching

The surplus sugar after the body processes the necessary sugar from food into energy stored as glycogen in the liver and skeletal muscles. Similarly, the body stores the extra fat in our diets in the adipose (fatty) tissues as triglycerides.

When on intermittent fasting, the body starts burning glycogen and body fat because fasting deprives the body of the glucose that comes from eating. The body enters a ketogenic state at that point. Since blood sugar levels do not rise, insulin production also decreases. The liver and pancreas healthily benefit from this.

Healthy Autophagy

New cells frequently replace old, damaged, and dead cells in the body due to the natural process known as autophagy. Intermittent fasting also enhances autophagy. As a result, it significantly lowers the likelihood of cancer and inflammation.

Adverse Effects of Intermittent Fasting

Hypo and Hyperglycemia

An intermittent fast may result in a sharp reduction in blood sugar levels in some individuals (hypoglycemia). It appears as lightheadedness or vertigo.

The individual can feel dizzy or perhaps faint. However, when people break an intermittent fast with a substantial or high-carbohydrate meal, their blood sugar levels may spike sharply (hyperglycemia). Frequent episodes of hypo- or hyperglycemia can be harmful and lead to several health issues.

Low Energy and Irritability

People on intermittent fasting take a few weeks to feel normal, healthy, or better. After that, the person may have poor energy and irritation due to altered eating schedules.

Binge Eating

As a direct result of the previous statement, people frequently overeat when they are already full. It defeats the aim and increases their danger compared to before they began the intermittent fasting programme.


People frequently forego drinking water along with food when fasting. It is dangerous and causes more problems. Whether on an intermittent fasting regimen or not, one should keep drinking the same amount of water daily.

Hormonal Imbalance

Intermittent fasting makes women more likely to experience hormonal imbalances. It may result in polycystic ovarian syndrome and late, early, and skipped periods (PCOS). Such imbalances can also make it more challenging to get pregnant.

Heartburn, Bloating, and Constipation

Constipation, bloating, and heartburn are all possible side effects of the illness mentioned above. Additionally, since the intermittent fasting program reduces the amount of solid food consumed by skipping one or more meals, individuals may have constipation for a few days while their bodies adjust to the diet. However, drinking enough water can help reduce digestive discomfort.

Acidic Body

Whether someone is fasting or not, the secretion still occurs. The stomach’s acidic gastric juice may irritate the stomach’s inner lining leading to ulcers or acid reflux.

Intermittent Fasting and Diabetes: The Relation

A brief review of type 2 diabetes (T2D) may be beneficial to comprehend how and why fasting can be successful. In its most basic form, type 2 diabetes occurs due to persistently high blood sugar levels and a diminished ability to respond to the hormone insulin, which aids the body in using carbs as fuel. In addition, genetic predisposition, as well as lifestyle elements like nutrition, exercise, sleep, stress, and environmental exposures, are among the factors that contribute to T2D.

Our body continuously produces many inflammatory cells leading to chronic inflammation. If you have a chronic illness like type 2 diabetes, it can worsen your situation. Chronic systemic inflammation can contribute to chronic health conditions like type 2 diabetes, heart disease and high cholesterol.

Focusing on improving insulin sensitivity, reducing chronic inflammation, and cardiovascular health—or, to put it another way, aiming to reverse the factors that contribute to T2D—instead of just lowering blood sugar is a helpful way to treat T2D. These are the goals of fasting regimes.

The advantages of intermittent fasting for patients with diabetes have not been thoroughly studied. About a decade ago, researchers began the first studies examining the effects of intermittent fasting on diabetes, and more recently, they have started including participants with prediabetes and Type 2 diabetes. However, most medical professionals still view fasting as somewhat experimental.

Mattson identified a variety of health advantages associated with intermittent fasting in a review article of recent research published in the New England Journal of Medicine. According to him, several physiological processes occur during intermittent fasting that can shield organs from conditions, including Type 2 diabetes, heart disease, age-related neurodegenerative disorders, inflammatory bowel disease, and numerous malignancies.

Additionally, a few current research that focused on fasting in persons with diabetes revealed minor health advantages:

  • According to a Canadian study that followed three persons with type 2 diabetes, fasting had several positive health effects, such as weight loss, better blood sugar regulation, reduced insulin resistance, and reduced insulin therapy requirement.
  • A study on a group of illnesses known as metabolic syndrome, which raises the risk of diabetes, heart disease, and stroke, was evaluated in 19 patients. When participants consumed food within a 10-hour window for 12 weeks, the study from the University of California, San Diego, revealed reductions in body weight.
  • In a different study, four prediabetic males were divided into two groups: one fasted for six hours, and the other ate continuously for 12 hours. Although the fasting group did not experience weight reduction or improved blood sugar levels during the five-week research, there were improvements in blood pressure, decreased insulin, and enhanced insulin sensitivity.

Popular Intermittent Fasting For Diabetes

12/12 method

It allows you to fast for 12 hours and then eat for the next 12. You might already be following this rule if you have breakfast at 9 am and dinner at 9 pm, for instance. The 14:10 diet is a version of this one where you fast for 14 hours a day and eat for 10 hours.

16/8 method

You fast for 16 hours and eat for the remaining 8 hours, as the name suggests. One can achieve this by skipping breakfast and eating lunch and dinner eight hours apart. Alternatively, one skips dinner in favour of eating breakfast, lunch, and a late-afternoon snack.

20/4 method

In this, you can eat for the final four hours after a 20-hour fast. It inevitably means that you only eat one meal every day.

5:2 Diet

You follow a 24-hour fast for the remaining two days of the week while eating normally and regularly the other five days.

Eat Stop Eat

It is a 5:2 Diet variant in which the two fasting days each week are not set and can be chosen at random.

Benefits of Intermittent Fasting for Diabetes

  • Increased weight loss while preserving muscle mass
  • Decreased low-grade systemic inflammation
  • Improved insulin sensitivity
  • Improved cholesterol
  • Improved cardiometabolic health

Potential Side Effects of Intermittent Fasting for Diabetes

Side effects of Intermittent Fasting include:

  • Bad breath (which often results from low-carb diets)
  • Trouble concentrating
  • Excessive hunger
  • Constipation
  • Irritability
  • Insomnia
  • Dehydration
  • Daytime sleepiness
  • Low energy levels may impact your ability to exercise, which is vital for people with diabetes.
  • A much higher risk of low blood sugar (hypoglycemia)
  • High blood sugar (hyperglycemia) can happen if the liver responds to fasting by releasing stored glucose

The HealthifyMe Note

Not all experts support that reducing blood sugar levels by intermittent fasting is manageable. However, according to some experts, daily caloric restriction and diets that simulate fasting are effective ways to lower blood sugar levels. But, it is best to consult your nutritionist before choosing intermittent fasting. They will assess your health and then recommend what is best for you.

Tips & Tricks for a Healthy Fasting Experience

  • Throughout the fasting and non-fasting phases, have a balanced diet. You should include foods from all the food groups. Avoid overeating when you aren’t fasting.
  • Eat foods that are more slowly absorbed right before you fast. That also applies to foods with a lower glycemic index as they contain a lot of fibre and digest slowly.
  • During the fast, eat things that will fill you up and maintain a stable blood sugar level. Examples include fresh salads, fruits, and vegetables.
  • Limit your intake of greasy or sugary foods when you break the fast. Instead of frying, try grilling, roasting or baking.
  • To prevent dehydration during the fast, consume plenty of liquids. AVOID sugary beverages.
  • Regularly check your blood sugar levels.
  • 16:8 Time-Restricted Feeding allows you to establish a consistent daily eating plan, making it simpler to implement into your daily routine than Intermittent Fasting.
  • Break the fast as soon as hypoglycemic symptoms appear. Utilise your plan of action, such as taking glucose pills and then having a snack. Before you start your fast again, consult with your doctor.
  • When you fast, check for hyperglycemia symptoms if you have type 1 diabetes. These include severe thirst, frequent urination, and weariness. If you experience any of these symptoms or if your blood sugar level continues to be high, speak with your doctor immediately.

Precautions Regarding Intermittent Fasting

Chronically Underweight and Eating disorders

Anyone with a history of eating disorders or chronic underweight must avoid intermittent fasting.

Pregnant and breastfeeding women

You should avoid intermittent fasting for pregnant or breastfeeding women. The caloric restriction caused by intermittent fasting can harm foetal development.

Furthermore, because breast milk nutrition is heavily influenced by what the mother eats, restricting one’s diet while breastfeeding can affect your milk supply.

Burnout and Stress

Low-calorie intake can lead to increased cortisol levels and psychological stress. Most people benefit from this mild stress. It does, after all, aid in our weight loss and cell renewal. However, extended intermittent fasting might overwhelm our body’s stress threshold and adversely affect people who already experience high levels of physical stress. It can also harm people who combine intermittent fasting with other activities like cold treatment or a lot of high-intensity training.


Those who are receiving insulin therapy or taking drugs that cause hypoglycemia should speak with their doctor before starting an intermittent fasting regimen because it directly impacts our body’s ability to produce blood sugar.


A popular dietary strategy for detoxification and weight loss is intermittent fasting. However, there are concerns regarding the safety of fasting for people with diabetes. There may be advantages for persons with type 2 diabetes, but further research is required.

Intermittent fasting can be safe for some because blood sugar levels fluctuate before, during, and after fasting. However, patients with diabetes may be at risk of hypoglycemia and hyperglycemia. Therefore, before beginning any weight loss program, consult a medical practitioner, a member of your diabetes care team, or a dietician. One can reduce weight safely and sustainably with their assistance.

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