Intermittent Fasting: What Is It?

Intermittent fasting is a popular trend for health and fitness. People use it to lose weight, have better health, and simplify their lives.

Many studies show it can have powerful effects on your body and brain. It may even help you live longer.

What is Intermittent Fasting

Intermittent fasting is when people eat only during a certain time. There are different types of intermittent fasting. One type is called the 16:8, which means people eat for only 8 hours and last for 16 hours.

Studies show that intermittent fasting can better your blood sugar and your cholesterol or even help you lose weight.

What is intermittent fasting

Sometimes, you can’t eat for a while. It’s not good to do this all the time. But it might be helpful if you are sick and need to get better. Or if you have a disease that is making your body hurt.

Also Read: Top 8 Best Keto Apps For Tracking Carbs and Lose Weight

Fasting is also an important religious practice. It is done by Christians, Jews, Muslims and Buddhists and is natural.

Techniques of Intermittent Fasting

Different techniques will work for different people. Figure out what works best for you.

But before doing intermittent fasting or deciding how often to fast, talk to a doctor first. Here are 4 popular ways of doing intermittent fasting:

  1. The 16/8 method
  2. The 5:2 diet
  3. Eat Stop Eat
  4. Alternate-day fasting

The 16/8 Fasting method

The 16/8 method is not to eat anything for 16 hours. During that time, you can have two, three or more meals.

It’s also known as the Leangains protocol and was made famous by fitness expert Martin Berkhan. You can do this by eating after dinner and skipping breakfast.


For people who like to eat breakfast, this method may be hard to get used to. But many people automatically do this anyway.

You can drink water and other beverages that have no calories during the fast. It is essential to eat healthy foods during your eating window if you want this method to work well.

Eating a lot of junk food or too many calories will make it hard for the diet plan to work well.

The 5:2 diet

The 5:2 diet

On fasting days, you eat only 500 calories. You eat what you usually eat 5 days of the week and then restrict your calorie intake 2 days of the week.

For example, on Mondays and Thursdays, women would restrict their intake to 500 calories each day, and men would restrict their intake to 600 calories each day.

This diet is also called “the Fast Diet” because British journalist Michael Mosley popularized it. And this diet is effective at helping people lose weight quickly.

Eat Stop Eat

Eat Stop Eat

Eat Stop Eat is a way to fast for 24 hours. You can do it for one day or two days.

For example, if you finish dinner at 7 p.m. on Monday and don’t eat until 7 p.m. on Tuesday, then you have just finished a full 24-hour fast.

You can also fast from breakfast to breakfast or lunch to lunch – the result is the same as doing one full day of fasting between them (7 pm-7 pm).

Water and other zero-calorie drinks are allowed during the fast, but no solid foods are permitted.

Alternate-day fasting

alternate day fasting

In alternate-day fasting, you don’t eat on one day. You can eat about 500 calories the next day.

A small study found that this is no more effective than a typical calorie-restrictive diet.

It may be too difficult for beginners to go without eating for the whole day one day and then eat tiny the next day.

It’s not recommended because you might feel hungry and dislike it much when you do this every other week.

Effects of Intermittent Fasting on Cells and Hormones:

When you fast, your body changes on the cellular and molecular levels. For example, your body lowers hormone levels to make stored body fat more accessible.

Your cells also initiate important repair processes and change the expression of genes. These are some changes that happen in your body when you fast:

Human Growth Hormone (HGH): The levels of growth hormone increase when you fast. The higher the levels, the more fat is burned, and muscles are built.

Insulin: Insulin sensitivity improves, and insulin levels drop. This makes it easier for the body to access stored fat.

Cellular repair: When you are fasting, cells will start to fix themselves. This includes autophagy when cells eat and remove old and dysfunctional proteins that build up inside them.

Gene expression: There are changes in genes that make them work better. The genes protect us from sickness and make people live longer.

Other Benefits of Intermittent Fasting

Apart from helping you lose weight, intermittent fasting helps lower blood insulin and sugar levels. Insulin regulates how much glucose is in your blood.

But sometimes, your body becomes resistant to insulin. This can make it hard for the body to respond as well as it should. Intermittent fasting helps correct this problem.

Intermittent fasting is when you only eat during certain times of the day. It makes people more energetic and less tired. It also helps their mental clarity and concentration. People who do this are more hypervigilant than those who don’t.

Side Effects of Intermittent Fasting

Those who do intermittent fasting experience mild side effects. One of these is constipation. But be aware, this is a normal response to eating less food. So don’t worry about it unless you have bloating or abdominal discomfort too.

Hunger is one of the side effects of starting an IF. It happens to most people. Other side effects are dizziness, heartburn, headaches and muscle cramps.

Related Article: What is Thermogenesis for Weight Loss and How to Achieve it?

These side effects are not dangerous, and you can manage them. Remember to stay hydrated and eat a healthy diet.


In doing Intermittent Fasting correctly and making sure it is in line with your body, mind, and soul (which will make you lose weight)–you can lose 2 to 6 kilograms each month.

You’ll see a lot of inches lost as well as an increase in energy levels and brain function.

But it’s also important to keep other factors like your age, physical activity levels, medicals (like diabetes), and stress levels in mind before deciding how much weight you want to lose or gain.

About Jessica J, M.D

Written & reviewed by Dr. Jessica J. Follow me on Pinterest & LinkedIn.