Stages of Intermittent Fasting by the Hour

Written by Andrew Brewer. ⚕️Reviewed and fact checked by our medical team.

Stages of Intermittent Fasting by the Hour

Intermittent fasting is one of the most popular dieting plans in the world right now. It’s a fantastic way to lose weight fast without putting your body at risk. Other diets can be way too restrictive and could lead to some harsh negative side effects. With intermittent fasting, weight loss is healthy and easy!

But what does intermittent fasting really do to your body? Why is it effective and what is happening as you fast?

One of the best ways to find success with intermittent fasting is to know what’s happening while it’s happening. Understanding intermittent fasting will enable you to see its benefits, not just on the scale. That’s why so many fantastic intermittent fasting apps have libraries of information for users to scour through and read.

To help you understand intermittent fasting, we’re going to take a look at the hour-by-hour breakdown of some of the most popular intermittent fasting methods. We’ll look at what’s happening in your body as you break your fast, eat throughout the day, and wind down in the evenings. We’ll also break down what is happening as you get deeper into your fasting session.

Effects on Your Body

Aside from assisting in weight loss, there are plenty of natural benefits that your body can experience with proper intermittent fasting. When you’re deep into your fasting period, there comes a point at which the body switches from processing calories to burning fat. This is known as ketosis and is a state your body only enters through long periods of fasting. Intermittent fasting is a safe and effective way to bring about ketosis in the body.

On top of that, your body’s immune system could slowly be trained to withstand more strain. There are some correlations discovered between intermittent fasting and improved immune systems as the body has to process less damaging food and receives quality substances for a short period of the day.

Finally, while breaking down your day into the ratios of fasting and eating, your body’s metabolic rate gets a massive boost. This helps facilitate weight loss as your body is not able and willing to shed the extra pounds. When you’re intermittent fasting, your metabolism skyrockets making weight loss much easier.

Key Takeaways

  • Intermittent fasting is a popular and effective way to lose weight without putting your body at risk.
  • Proper intermittent fasting can also offer other benefits such as an improved immune system and a boost in metabolic rate.
  • The hourly method of intermittent fasting is a popular approach where you eat within a specific time frame and then fast for the remainder of the day.
  • The Eat-Stop-Eat method involves two days of the week where you fast for 24 hours and then eat normally for the remaining days to avoid overwhelming your system.
  • It’s important to understand what’s happening in your body during intermittent fasting to see its benefits beyond weight loss.

Hourly Fasting Methods

Let’s start with one of the most popular methods of intermittent fasting – the hourly method. These methods are where you eat all of your calories for the day within a specified time frame and then fast for the remainder of the day. This fasting plan typically occurs every day and is one of the most common intermittent fasting plans for starters and veterans alike.

  • 16:8 – For this intermittent fasting method, you have 8 hours throughout the day to eat and then 16 hours for fasting. Let’s start with breaking your fast.
    • When you break your fast, your body needs to ease its way back into eating. Around noon, you’ll start to receive signs from the stomach that it’s hungry, but you shouldn’t overload it. At this point, your fast is concluded and your stomach needs more nutrients to burn through so eating should commence.
    • As you eat throughout the day, your stomach will return to its normal rhythm as you supply it with foods to break down and process. Eating throughout the day provides the calories and nutrients your body needs to function.
    • Near the end of the day, it’s time to start winding down your eating and transitioning to certain drinks like water or tea. At this point, your stomach has all of the calories and nutrients it needed for the day and can start focusing on processing them and moving on to fats.
    • Once your body has worked through all of the calories you provide throughout your time eating, it then turns to fats and unwanted extras. By the time your intermittent fasting is coming to an end, your body has processed much more of the unwanted fats and calories than it would have otherwise.
  • 20:4 – This intermittent fasting method is similar to the one above, but the fasting time is increased. This means you have less time to eat throughout the day but your body has more time to process the food you did eat. The breakdown is essentially the same with one key difference.
    • Throughout the day, your body is processing the calories and nutrients you provided as you ate. However, your body now has more time to process these calories which will ultimately lead to more fats burnt and more unwanted calories processed. The longer fasting time allows your body to focus on body fat for a longer period.
  • 22:2 – Just like the above two intermittent fasting methods, this designates when you should eat throughout the day and when you should fast. The fasting time is much longer for this method, so some experts recommend limiting the number of times throughout the week in which you should partake in this plan.
    • This intermittent fasting methods provides your body 22 hours throughout the day to process food and turn its focus to body fat and other extras in your body. It’s certain to help you drop weight fast, but it can be quite rigorous on the body.
    • If you limit the number of intermittent fasting days throughout the week, then your body will have some time to recover. Long periods of fasting can be difficult for the body, so it’s important to know your limits. When you enter in a break day, your body will return to normal and ease its way into the intermittent fasting.


This method involves taking two days out of the week where you simply do not eat any calories. The Eat-Stop-Eat method requires you to forgo food and partake in a 24-hour fast. These two days of the week must be separated by at least one day where you eat normally to keep yourself safe and not overwhelm your system by fasting.

Let’s take a look at the hour-by-hour breakdown of this method of intermittent fasting.

Days on refers to the days in which you are fasting. On these days – typically from the end of dinner the night before to the same period, 24 hours later – you go without food. You can drink tea, coffee, water, etc. to tide you over.

When the fasting starts, your body is breaking down the food from the day before. It’s processing the calories and dealing with the nutrients you’ve just put into your body. Your body still believes it’s in a normal eating cycle.

Once the fast starts to become clear to the body, it diverts its attention from breaking down food and processing calories to burning fat and handling the hours of no nutrients. This is simply a longer version of the hourly intermittent fasting system. Your body now has a full day to process food from the day before and can focus on burning fat and unwanted calories.

As you near the 24-hour mark, your body is likely to have switched over to burning fats and dealing with the breakdown of unwanted extras in your system. Now it’s time to ease it back in with soups or gentle solid foods.

Your body then returns to the normal process of breaking down foods, processing calories, and dealing with a normal day of eating. This helps it reset and prepare for the next 24-hour day of intermittent fasting.

Don’t forget to check our best fasting apps to make your intermittent fasting journey easier.


  • What are the stages of intermittent fasting by the hour?

The stages of intermittent fasting by the hour are:

Stage 1: 0-4 hours after eating

Stage 2: 4-8 hours after eating

Stage 3: 8-12 hours after eating

Stage 4: 12-16 hours after eating

Stage 5: 16-20 hours after eating

Stage 6: 20-24 hours after eating

  • What happens during stage 1 of intermittent fasting?

During stage 1, the body is in the fed state and is digesting food. As a result, insulin levels are high, and the body uses glucose as its primary energy source.

  • What happens during stage 2 of intermittent fasting?

During stage 2, insulin levels drop, and the body uses stored glucose for energy.

  • What happens during stage 3 of intermittent fasting?

During stage 3, the body enters the fasted state, and insulin levels continue to drop. The body starts to burn stored fat for energy.

  • What happens during stage 4 of intermittent fasting?

During stage 4, the body is in a deep, fast state, and insulin levels are at their lowest. As a result, the body continues to burn fat for energy and begins to produce ketones.

  • What happens during stage 5 of intermittent fasting?

During stage 5, the body continues to produce ketones and undergoes autophagy, which is a process where the body cleans out damaged cells and cellular debris.

  • What happens during stage 6 of intermittent fasting?

During stage 6, the body is in an extended fasted state and the production of ketones increases. In addition, the body continues to undergo autophagy, and some studies suggest this stage may have additional health benefits.

  • How long should I fast during intermittent fasting?

The length of the fast depends on the individual and their goals. For example, some people may fast for 16 hours, while others may fast for 24 hours or longer. It’s essential to listen to your body and consult a healthcare professional before starting an intermittent fasting regimen.

Andrew Brewer

Andrew Brewer

Andrew Brewer started to give people the guidance that he never received when he was first starting. His goal is to make your goals achievable and to offer you only the best fasting apps that the internet has to offer. You're not on your own - Andrew and the entire family of reviewers at are here with you every step of the way!