12 Minutes

Edited & clinically reviewed by SENSES Team
Fact checked

Intermittent fasting aims to boost weight loss by placing you in a calorie deficit, but many individuals practice it for other medical benefits as well. When the body enters ‘starvation mode’ during a fast due to low blood glucose, it initiates a homeostatic mechanism known as autophagy, which may be advantageous in disease prevention.

Intermittent fasting is an eating strategy that alternates between periods of fasting and eating. Intermittent fasting has been shown in studies to help people lose weight and avert or even reverse some diseases. Intermittent fasting is a way of eating in which you eat during certain times of the day and do not eat during others. These periods can vary from many hours of fasting every day to fasting almost every day of the week, based on the form of intermittent fasting you choose.

So what’s the hidden truth? Is it safe to do so? Is intermittent fasting suitable for everyone? Are there any negative consequences? Continue reading to learn about the science of intermittent fasting.

When it comes to dieting, most people are concerned with what they should eat, but with intermittent fasting, it’s all about when.

Intermittent fasting requires that you only eat at a certain time of day. In order to help the body burn fat, you may choose to fast for a set amount of time each day or consume only one meal a few days per week. In addition, research suggests that it may have some health benefits.

Intermittent fasting has been investigated by John Hopkins neurologist Mark Mattson for 25 years. He claims that our systems have grown to be able to go on without food for lengthy periods of time, even for days or weeks. Before humans learned to farm and cultivate, they were hunter-gatherers who had adapted to go extended periods of time without eating and still flourish. Hunting games and gathering nuts and berries required a lot of time and effort.

Just fifty years ago, maintaining a healthy weight was a lot easier. Even television shows were off at 11 p.m. in this era. After dinner, everyone would go to bed and stop eating. The portions were significantly smaller than they had been in the past. There was an increase in the number of people engaging in physical activity outside of the workplace.

Everything from television to the internet is available all the time these days. The shows we love, the video games we play, and online chats keep us up late. All day and most of the night, we’re hunched over the table, munching on snacks.

Obesity, heart disease, type 2 diabetes, and other ailments can result from a diet high in calories and low in physical activity. Intermittent fasting may be able to reverse these trends, according to scientific research.

The theory behind intermittent fasting is that by reducing eating, our systems would utilize our fat stores for energy more rapidly and efficiently. Although glucose from carbs is one of our most direct sources of fuel, when glucose is unavailable, we use fat for energy. This is especially true during times of food scarcity. Our capacity to store fat is limitless.

There are numerous ways to practice intermittent fasting. There is no such thing as a “perfect” fasting plan, and it should be centered on what works best for you.

Fasting for a specified amount of time each day, usually twelve hours or more, is one way. The average person sleeps approximately 7 hours each night, which goes towards the fasting time. If you don’t eat after dinner, you can easily achieve a daily fast, which will help your body burn fat more effectively. This form of fasting may be beneficial for someone who is a nighttime snacker.

Alternate day fasting is another type of intermittent fasting. This is where you eat anything you want five to six days a week and fast one or two days a week. Water and broth are advised during fasting days to avoid dehydration. This form of fasting may be advantageous for someone who has a busy work schedule and cannot eat on a routine basis

Intermittent fasting can be done in a variety of ways, but all rely on setting apart regular periods of time during which one will eat and fast. You could, for example, only eat for 8 hours a day and fast the rest of the time. One option is to eat just one meal a day on 2 days of the week. Intermittent fasting can be done in a variety of ways.

After a long period of time without meals, the body begins to burn fat as a source of energy. Metabolic switching is the term used to describe this phenomenon.

Intermittent fasting is a radical departure from the typical American eating pattern, in which most people eat throughout the day. If a person isn’t exercising while eating three meals and several snacks a day, they aren’t burning off the calories they consume.

With intermittent fasting, you extend the time after your last meal, when your body has burnt all the calories you ate and has begun burning fat, for fat loss.

Before embarking on an intermittent fasting regimen, you should consult your doctor. As soon as you have the go-ahead from him or her, the process is straightforward. Each day you can choose to restrict your eating to a six- or eight-hour window. Fasting can be done in a variety of ways, including 16/8 fasting, when you eat for 8 hours then fast for 16. It’s not difficult for the majority of people to maintain this behavior pattern over the long run.

Another is the 5:2 diet, which advocates eating the same thing 5 days a week instead of two. One 500–600 calorie dinner is all you can eat on the other 2 days. Every other day of the week, you’d eat as normal, but on Monday and Thursday, you’d have a one-meal day.

Fasting over longer lengths of time, like 24, 36, 48, and 72 hours, may be harmful as well as ineffective. Starvation might cause your body to store more fat if you don’t eat for a long period of time.

According to Mattson’s findings, acclimatization to intermittent fasting can take anywhere from 2 to 4 weeks. While you’re getting adjusted to the new pattern, you can feel hungry or cranky. Participants who make it through the adjustment stage, however, are more likely to remain with the plan because they discover they are more comfortable with it.

According to studies, intermittent fasting does more than just burn fat. Metabolic switching is the key component responsible for the residual effects of intermittent fasting. Mattson describes how this metabolic switch impacts the body and the brain when it is triggered. 

In a New England Journal of Medicine study, Mattson found evidence of numerous health benefits linked with the practice. Longevity, physical fitness, and mental sharpness are just a few of the benefits to look forward to.

Intermittent fasting helps protect organs from chronic diseases such as heart disease, type 2 diabetes, aging-related neurodegenerative disorders, and even inflammatory bowel disease and many malignancies by causing a variety of physiological changes.

Numerous advantages of intermittent fasting are ascribed to fasting for at least 12 hours per day, while another study suggests that 16 hours of fasting may be necessary.

The liver glycogen reserves are depleted, metabolic pathways are altered, and favorable health consequences are found during 12–36 hours of sustained fasting.

Intermittent fasting benefits are numerous. Here are some of the scientifically supported benefits:

Low blood ‘bad’ cholesterol

Cholesterol levels appear to have improved in both human and animal studies. A rise in HDL or “good” cholesterol, as well as a decrease in triglycerides, can be achieved with intermittent fasting.

Heart disease is linked to high levels of total cholesterol, LDL cholesterol, and triglycerides.

Managing blood sugar levels

Insulin resistance and insulin sensitivity are reduced by intermittent fasting, which can lead to better blood sugar control over time.

Lower fasting blood glucose and glycated hemoglobin (HbA1c) values can be expected as a result of this strategy.

It has been shown that intermittent fasting may minimize the need for insulin therapy in male adults with type 2 diabetes in studies.

Changes in body composition

Intermittent fasting healthy diets have been examined extensively for their impact on body weight and composition.

Intermittent fasting has been proven to result in weight loss of between 3 percent and 7 percent of body weight in an average of eight weeks. It’s also been shown in studies that this technique can help people slim down.

There are many ways to reduce the risk factors of metabolic syndromes, such as decreasing waist circumference and body fat percentage through the use of 14:10 fasting (eating for ten hours and fasting for fourteen hours a day).

As a result, intermittent fasting can reduce the risk of heart disease and type 2 diabetes by reducing the number of risk factors that contribute to metabolic syndrome.

Helps with brain health and function

Intermittent fasting may boost cognition and improve memory while also supporting brain health and function by preserving neurons in the brain from degeneration and failure.

Emerging data indicate that intermittent fasting may be beneficial in neurological illnesses such as Parkinson’s, Alzheimer’s, epilepsy, and stroke.

Bear in mind that it’s not just fasting that may have these potential advantages; lower inflammation, body fat loss, and better blood glucose levels have all been related to better brain function.

Maintains cell health and vibrance

Fasting allows our bodies to relax and repair, adhering to natural processes that keep our cells healthy. Autophagy is an example of a primary process that our bodies go through to keep our cells healthy, and hence make us healthy!

Autophagy is the process by which our cells eliminate waste and defective cells in order to assist our bodies in cleaning out damaged cells and regenerating new and healthier cells. Evidence suggests that when we fast intermittently, we accelerate the frequency of this process, causing our bodies to work harder to eliminate any undesirable garbage and dysfunctional cells.

Increased autophagy may protect us from a variety of diseases such as neurological disorders, inflammatory diseases, cancer, and cardiovascular diseases.

It may prolong your life

There are various reasons why intermittent fasting may improve our life span; weight loss, lower blood pressure, and the majority of the benefits mentioned above may all help to extend our lives while improving our quality of life.

In animal experiments, intermittent fasting has been shown to improve life expectancy and markers for health, metabolic response, stress, and age-related disorders.

These findings are difficult to establish in human trials because of the numerous factors that influence epidemiological studies and the numerous types of fasting. However, some of the advantages of intermittent fasting may improve our overall quality of life and lower our risk of chronic disease.

Could help with cancer prevention and treatment

This possible advantage is still up in the air. Periodic fasting has been proven in animal models to protect normal cells from the harmful effects of chemotherapy medications while tuning cancer cells to the treatment.

Human trials have yet to yield conclusive results. Weight management and reduced inflammation in the body may help to prevent cancer growth, but more research is needed to fully know the function fasting may play in cancer treatment.

Could promote balance in areas other than food

We automatically think of food when we talk of intermittent fasting since that is what we are restricting. But, could we gain from a break from other aspects of our lives?

Because the core premise of fasting is to refrain from something for a set amount of time, what else may we fast from except food?

Television, video games, and social media, to mention a few, may all be things we might do without that would benefit our health and well-being.

Finally, actively choosing to minimize or modify our habits can assist us in developing health and wellness objectives based on our beliefs and values.

Additional intermittent fasting health benefits

Breast cancer and other inflammatory disorders may be reduced by cutting back on calories in the evenings and fasting for longer durations at night, according to a 2015 assessment of 2,650 adult females.

A 16-year study of observational data on 26,092 adult males found that limiting late-night snacking and eating could dramatically lower the risk of heart disease.

Longevity and neurodegenerative diseases like Parkinson’s disease are two other areas of health where intermittent fasting is being studied.

Quality of the evidence for beneficial effects

The majority of research on intermittent fasting is derived from animal studies, and there is a little long-term human study on the subject at hand.

Furthermore, according to a 2021 assessment, only six of 104 reported beneficial properties of intermittent fasting were backed by moderate- to high-quality evidence, with the majority of findings based on low-quality studies.

Human studies on the long-term health advantages of intermittent fasting are necessary because of this finding.

People with high cholesterol, irritable bowel syndrome, or arthritis may attempt intermittent fasting as a way to treat their symptoms. However, not everyone is a good fit for intermittent fasting.

A primary care physician should always be consulted before beginning any diet, including intermittent fasting. Intermittent fasting can be unhealthy for some people:

  • Children and adolescents under the age of 18.
  • Pregnant and breastfeeding women.
  • Diabetics or those with blood sugar issues.
  • Anorexia or other forms of binge-eating disorder may be at risk.

As long as a person can properly follow an intermittent fasting routine, they can do so for the rest of their lives. It might be a life-altering change, but it can also be beneficial.

The effects of intermittent fasting can vary from person to person. If you begin to experience unusual anxiety, nausea, headaches, or other symptoms after beginning an intermittent fasting regimen, you should consult your physician.

FAQs