top of page
  • Writer's pictureHema Chakraborty

What is intermittent fasting and how does it function?

An eating strategy known as intermittent fasting alternates between fasting and regular mealtimes. According to research, intermittent fasting can help you control your weight and potentially prevent or even reverse some diseases. But how do you go about it? Is it safe, too?

What is Intermittent fasting?

While many diets concentrate on what to eat, intermittent fasting only considers when to eat.

You only eat during the allotted hours when you practice intermittent fasting. Your body can burn fat if you fast for a set period of time each day or consume only one meal a couple of days a week. Additionally, there are some health benefits, according to scientific findings.

Mark Mattson, a neuroscientist at John Hopkins, has been researching intermittent fasting for 25 years. According to him, our bodies have evolved to be able to survive for several hours, or possibly several days or more, without eating. Prior to learning how to cultivate crops, early humans were hunters and gatherers who developed the ability to live for extended periods of time without food. Hunting wildlife and gathering nuts and berries required a lot of time and effort.

It was simpler to maintain a healthy weight even 50 years ago.

Christie Williams, M.S., R.D.N., a nutritionist at Johns Hopkins, explains: "There were no computers, and TV programmes ended at 11 p.m.; people stopped eating because they went to bed. There were much fewer portions.

In general, more people exercised and worked and played outside. TV, the internet, and other forms of entertainment are now accessible around the clock. To watch our favorite programs, play games, and chat online, we stay up later. We spend most of the day and night lounging around and munching.

A higher risk of obesity, type 2 diabetes, heart disease, and other ailments can result from eating more calories and being less active. According to scientific research, intermittent fasting might be able to buck these tendencies.

How does an Intermittent fasting process work?

There are many various approaches to intermittent fasting, but they all start with deciding on a regular eating and fasting window of time. You may, for instance, try eating only for eight hours each day and fasting for the other sixteen. Or you could decide to only eat one meal each day for two days per week. There are numerous variations of intermittent fasting plans.

According to Mattson, the body runs out of sugar after several hours without eating and begins to burn fat. This is referred to as metabolic switching by him.

"Intermittent fasting contrasts with the typical American eating habit, which involves eating throughout the day," claims Mattson. "If a person is eating three meals a day plus snacks and isn't exercising, they are burning off their fat storage instead of burning those calories every time they eat."

By extending the time until your body has burnt through the calories from your most recent meal and starts burning fat, intermittent fasting works.

Plans for intermittent fasting

It's crucial to see your doctor before beginning an intermittent fasting regimen. Once you have their approval, the actual practice is easy.

You can choose a daily strategy that limits daily meals to one six- to eight-hour window each day. Consider attempting the 16/8, which involves eating for eight hours and fasting for sixteen. Williams is an advocate of the daily routine, claiming that most people find it simple to maintain this pattern over time.

One more is the "5:2 strategy," which calls for eating consistently five days a week.

You restrict yourself to one 500–600 calorie meal on the other two days. For instance, if you decided to eat normally every day of the week except for Mondays and Thursdays—those days would be your one-meal days—you would choose to do so.

Fasting for longer lengths of time—such as 24, 36, 48, and 72 hours—is not always beneficial for you and may even be harmful. If you go too long without eating, your body may begin storing extra fat as a defense against famine.

According to Mattson's studies, it can take the body two to four weeks to adjust to intermittent fasting. As you get adjusted to the new pattern, you can feel hungry or irritable. But he notes that once the adjustment period is over, research participants often continue with the strategy because they start to feel better.

While intermittent fasting, what may I eat?

Water and zero-calorie drinks like black coffee and tea are OK while you aren't eating.

Additionally, "eating properly" at your eating times does not include bingeing. If you fill your mealtimes with high-calorie junk food, enormously big fried foods, and desserts, you won't likely lose weight or get healthy.

Williams appreciates that intermittent fasting permits a variety of foods to be consumed and savored. She explains, "We want people to be conscious and enjoy eating delicious, nutritious cuisine. She continues by stating that dining with friends and enjoying meals together increases enjoyment and promotes excellent health.

Williams agrees with the majority of nutrition experts in that whether you choose to practice intermittent fasting or not, the Mediterranean diet serves as a solid example of how to eat. When you choose complex, unprocessed carbohydrates like whole grains, leafy greens, healthy fats, and lean protein, you almost never go wrong.

Benefits of Intermittent Fasting

According to research, intermittent fasting does more than only burn fat. The body and the brain are affected when changes to this metabolic switch take place, according to Mattson.

Data about a number of health advantages connected with the practice were revealed in one of Mattson's studies that were published in the New England Journal of Medicine. A longer lifespan, a slimmer body, and mental clarity are a few of these.

  • Both memory and thought. According to studies, intermittent fasting improves verbal memory in adult people and working memory in animals.

  • Heart wellness. Blood pressure, resting heart rates, and other heart-related parameters were all improved by intermittent fasting.

  • Physical activity. 16-hour fasting young males demonstrated fat reduction while retaining muscle mass. Mice that were fed on different days displayed greater running endurance.

  • Obese people with type 2 diabetes. Intermittent fasting prevented obesity in animal trials. Additionally, obese adult adults lost weight by intermittent fasting in six brief experiments.

  • Type 2 diabetics might gain from: The majority of the existing data demonstrates that intermittent fasting can reduce insulin resistance, decrease fasting glucose, fasting insulin, and fasting leptin levels while boosting adiponectin levels and reducing body weight. According to certain research, some patients who practiced intermittent fasting under their doctors' supervision were able to stop requiring insulin medication.

  • Tissue wellness. Intermittent fasting decreased tissue damage during surgery and enhanced outcomes in rats.

Is Intermittent fasting safe?

Some people experiment with intermittent fasting in an effort to lose weight, while others use the technique to treat long-term ailments including irritable bowel syndrome, high cholesterol, or arthritis. But not everyone should practice intermittent fasting.

Williams emphasizes that you should consult with your primary care physician first before attempting intermittent fasting (or any diet).

Some individuals should refrain from attempting intermittent fasting:

  • Under-18 kids and teenagers

  • Women who are nursing or pregnant.

  • Those who take insulin and have type 1 diabetes. There have been no investigations in individuals with type I diabetes, despite an increasing number of clinical trials demonstrating the safety of intermittent fasting in those with type 2 diabetes. According to Mattson, there is concern that an intermittent fasting eating pattern could lead to hazardous levels of hypoglycemia during the fasting period because people with type I diabetes require insulin.

  • Those who have a background in eating disorders.

However, according to Williams, those who are not in these groups and who can safely practice intermittent fasting can keep up the routine indefinitely. It can be a beneficial shift in lifestyle, she explains.


Remember that different people may respond differently to intermittent fasting. If you begin to experience unusual anxiety, headaches, nausea, or other symptoms after beginning intermittent fasting, consult your doctor.

17 views0 comments


bottom of page