Intermittent fasting can involve going a full day without eating. It may help your body use stored fat for energy, but there may be risks involved.
Not eating for 24 hours at a time is a form of intermittent fasting known as the eat-stop-eat approach.
During a 24-hour fast, you can only consume calorie-free beverages. When the 24-hour period is over, you can resume your typical intake of food until the next fast.
This practice may not be safe for everyone. It’s important to speak with a doctor about whether it will be safe for you to do so before fasting.
Learn more about what happens to your body if you don’t eat for a full day, the benefits, and whether it is safe.
In addition to weight loss, intermittent fasting may positively affect metabolism, boost cardiovascular health, and more. It’s typically safe to use this approach once or twice a week to achieve your desired results.
Although this technique may seem easier than cutting back on daily calories, you may find yourself quite “hangry” on fasting days. It can also cause severe side effects or complications in people with certain health conditions.
You should always talk with a doctor before going on a fast. They can advise you on your individual benefits and risks. Keep reading to learn more.
You’ll be well into your 24-hour period before your body realizes that you’re fasting.
During the first 6 hours, your body will continue to digest your last intake of food. Your body will use stored glucose, called glycogen, as energy and continue to function as though you’ll be eating again soon.
After several hours without eating, your body will begin to use stored fats for energy throughout the remainder of your 24-hour fast.
Fasts that last longer than 24 hours may lead your body to start converting stored proteins into energy.
More research is needed to fully understand how intermittent fasting can affect your body. Early research does suggest a few benefits, though.
Help with weight loss
Fasting 1 or 2 days a week
Manage cholesterol and sugar levels
Regular intermittent fasting may help improve how your body breaks down cholesterol and sugar. These changes to your metabolism may help reduce your risk of developing conditions like diabetes and cardiovascular disease.
Reduce risk for coronary artery disease
A regular 24-hour fast may help reduce trimethylamine N-oxide levels in the long term. High levels of this compound are tied to coronary artery disease, so this may help reduce your risk.
Frequently fasting for 24 hours at a time can lead to side effects and increase your risk for certain complications.
Always talk with a doctor before going on a fast to help reduce your risk for any unforeseen health consequences. This is particularly important if you have underlying health conditions.
You shouldn’t fast if you:
- have or have had an eating disorder
- have type 1 diabetes
- are pregnant or breastfeeding or chestfeeding
- are under the age of 18
- are recovering from surgery
Fasting more than twice per week may increase your risk for heart arrhythmias and hypoglycemia.
Keep in mind that more research is needed to fully assess the potential benefits and risks of intermittent fasting. Exercising regularly and eating a balanced diet are proven methods for living a healthier lifestyle and maintaining your weight.
During a 24-hour fast, it’s important to drink plenty of water—more than your usual 8 glasses.
You won’t be ingesting any water from food during this time, and your body needs water to function. Water helps your digestive system regulate your body temperature benefits your joints and tissues, and can keep you feeling energized.
You should drink water as you feel thirsty throughout the day. The amount you should drink varies from person to person and depends on your activity level.
You can perform a 24-hour fast whenever you choose. You just have to make sure that you prepare for your fasting day in advance. Eating healthy and well-rounded meals prior to the fast will help your body get through the 24-hour period.
Some foods you should consider eating prior to fast include:
- foods rich in protein, such as nut butter and beans
- dairy products low in fat, such as low fat yogurt
- fruits and vegetables
- Whole grain starches
Foods high in fiber can help your body feel full long after eating. Fruits and vegetables contain water, giving you more hydration.
Keep in mind that beverages with caffeine may cause you to lose more water. Drink an additional cup of water for every caffeinated beverage to help balance your intake.
You may want to have a small snack or eat a light meal when your fast ends to help you ease back into your regular eating routine.
It is important to be cautious when trying this approach. Talk with a doctor about your health before attempting it on your own. They can help you understand individual benefits and risks, as well as advise you on how to conduct this type of fast in a healthy and safe way.