7 Things That Happen to Your Body When You Fast

Intermittent fasting is gaining huge popularity as a dietary option, but what actually happens to your body when you fast? We went ahead and found out.

At Bright Side, we know our readers are beautiful and awesome, so we keep collecting tips and tricks for you all to stay that way! Whether you fast for dietary reasons or as a religious necessity, here's exactly what happens to your body when you fast.

Sugar breakdown

The first hours of fasting are pretty normal for most people since your body is going through the regular process of breaking down glycogen and storing glucose as fuel for energy. Usually, about 25% of that goes right to your brain while the rest supports red blood cells and muscles.


After 5-6 hours depending on the sugar levels in your blood, you will reach the stage of ketosis - metabolic state, during which your energy levels are supported by ketone bodies in your blood. This is a process of fat breakdown since broken down fat results in ketone bodies.

This is the moment when the actual fasting starts, so it is a desirable state to be in for people who are fasting for weight loss. This state can be also reached by staying on a ketogenic diet which is based on a high fat, low carb diet.

Cholesterol and uric acid clean-up

During the process of ketosis, several more important things will happen: your body will release cholesterol and uric acid into the bloodstream which is a part of a detoxication process in the body.

During this stage, you may experience headaches, dizziness, fatigue, skin rashes, muscle pain, and joint aches in rare cases. At the end of this stage, the pain will be lessened and blood pressure will drop. The calcification process, cholesterol and mucoid plaque (alternative medicine) will be reduced.

Resting of the digestive system

Since your food intake has been reduced, the digestive system may take a rest. But since the digestive process takes time, it's never fully stopped during intermittent fasting - only during the prolonged one.

Emotional detox

After the first 6 hours of fasting, you will find yourself feeling hungry and maybe even overwhelmed. It may trigger some emotions like anger, frustration, feeling down or sadness. It is crucial to deal with those emotions as they come and to remind yourself that there is a perfectly logical reason for your fasting.

Try not to take out your emotions on people in your life and take some time to meditate or concentrate on something else rather than being hungry. Focus on an activity that doesn't require a lot of bodily effort.

Two ways to fast

Intermittent fasting is a method of fasting mostly used by people who would like to regulate their weight and calorie intake. The practice involves eating during certain hours of the day and abstaining from food during other hours. This helps regulate "mindless munching" and still lets you eat your daily calorie count during "eating hours". The most popular schedule for intermittent fasting is 8 eating hours with 16 hours of fasting - either in bulk or split throughout the day.

Prolonged fasting is a fasting experience during which you consume only drinks (most popular are water fasting and juice fasting). This type of fast requires a consultation with a health professional who will decide if this method is safe for you in your state of health in the first place. If your body can handle the prolonged fasting method, you would most likely be suggested to do a week-long detox program that would also include supplements and digestive support meds.

The benefits of fasting

In conclusion, we want to list several benefits that fasting can have on your life and overall health.

  • It's the perfect tool to use when trying to control your weight.
  • It's a good way to normalize insulin sensitivity and as a result, prevent type 2 diabetes.
  • It normalizes ghrelin levels and helps to "discipline your hunger".

  • It lowers triglyceride levels, lowering risks of heart disease.

  • It may slow down the aging process.

  • It may help with skin conditions.

  • It can help to normalize the digestive system.

Did this article make you wonder if you'll ever try fasting? Please share your thoughts with us in the comments below, we would love to hear from you!

Illustrated by Daniil Shubin for Bright Side
Share This Article