Intermittent Fasting After a Cheat Day (Why It Works)

Want to know if fasting after a cheat day can undo the damage of the binge? 

The good news is that you can fast the day after a cheat, yet most aren’t doing it correctly. Strategically having a cheat day can give you a break from the diet while possibly boosting your results.

But having a cheat day at the wrong time and then trying to follow it up by fasting can derail your progress. So the next thing you know, you’ve fallen off your diet altogether and have to restart at square one.

Here I’ll show you how to fast after cheat day so you can maximize your results while still allowing yourself to splurge once in a while.

Fasting correctly after your cheat day can reignite your metabolism and keep you on track for results.

Should You Have a Cheat Day?

Cheat days can be an essential part of dieting. A cheat day is a day when you allow yourself to eat foods that are not part of your diet. This could include anything from pizza to cake to ice cream.

Cutting down your calories too much for too long can slow down your metabolism through a process called “metabolic adaptation.”1

This is from reduced leptin levels. Leptin is a hormone that is produced by fat cells. It signals your body to burn your fat for fuel.2

But leptin can decline so much when you’re dieting that its low levels in your body slow down your metabolism.3

So by strategically adding in a cheat day, you can boost your leptin levels back up to reignite your fat burning.4

Plus having a cheat day or some cheat meals spread throughout the week can give you a break from dieting.5 It’s easier for most to stick with their diet if they can have a cheat day once a week. 

Then the best thing you can do after a cheat day is to fast the following day. 

Why Fast After Cheat Day

You can’t ruin your diet in one day if you get right back on the dieting horse. And the worst thing you can do is keep the cheat days going for multiple days in a row.

You won’t gain real weight overeating for just one day. Most of it will be water weight you can quickly flush out the next day or two with fasting.

You’re usually overeating on carbs and sodium on a cheat day, both of which cause you to hold water weight.

Detoxing after a cheat day with a fast can cleanse your body from all the water weight. Your body stores carbs from glycogen in your muscles and liver for energy.

Glycogen pulls and holds water to it. For every gram of glycogen, you’ll have 3-4g of water.6

So by fasting the day after a cheat meal, you’ll start utilizing those glycogen stores for fuel.

Once you start burning through the glycogen, you’ll also flush out the water retention.

Some can even trigger the keto whoosh effect by having a cheat day or cheat meal, the process of breaking through a plateau by flushing out stored water weight. 

You’ll also have a high influx of calories on your cheat day, so it’s a good idea to balance those calories by fasting.

This dieting approach of fasting and then eating what you want the next day is known as Alternate Day Fasting or Fasting Every Other Day diet.

Fasting the day after a cheat day is a lot easier since your body will be filled with calories and glycogen.

How to Fast After Cheat Day

So many hours should you fast following a cheat day? You’ll want to fast at least 16 hours the next day to get rid of the cheat day weight.

Ideally, you’ll fast for 16-20 hours or possibly even the entire 24 hours following your cheat day. 

The longer you can, the better you’ll burn through the stored glycogen and flush out the water weight. But fasting the entire day following a cheat day can be too hard for some.

You can have some approved drinks to make it easier to get through your fast. These drinks can help to boost your metabolism and make you feel full without breaking your fast.

These approved fasting drinks include:

You can even add in C8-MCTs to your coffee with this keto coffee creamer to boost your fat-burning even more.

The MCTs are quickly converted into ketones in your liver. These ketones help to trigger a “metabolic switch” in your body to start burning your fat stores for fuel.7

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That’s when having a single meal following your cheat day can make it easier to make it through the day.

You’ll be breaking your fast. But if you keep your calories low, you should continue to burn through glycogen and re-balancing your calories.

This is known as the OMAD diet (One Meal a Day). This is a diet where you only eat one meal per day.

This could be lunch or dinner, but it’s usually recommended to have your one meal later in the day.8 This is so you’re not going to bed feeling hungry.

This can be a great way to break through a weight loss plateau. You’re automatically cutting down your calorie intake for the day by only eating the one meal. 

It’s effective to work out while fasting to burn off even more fat and calories. You should have extra glycogen and energy from the influx of calories that’ll fuel you for the workout.

How You Should Eat Following a Cheat Day

The day after a cheat day, you should keep your calories and carbohydrates to a minimum.

The high influx in calories and carbs will cause the cheat day weight gain. But once you lower them back down, you should flush out this water retention fast.

With fasting, you won’t be consuming any real amount of calories. I know many aren’t able to do a pure clean fast.

But dirty fasting can be nearly as effective and easier to get through your fasting window.

Clean fasting is when you strictly only drink water. But dirty fasting allows other drinks such as coffee, tea, etc.

Coffee and tea make it easier to get through your fast since they’re satiating.9

You’ll feel fuller after drinking them. This makes it much less miserable to beat the hunger pangs that come with fasting.

Plus, they’re both thermogenic. They’ll boost your metabolism and help some to burn off those calories from the day before.10

You can also put some MCTs into your coffee to boost your metabolism even further. They”re also satiating making it easier to suppress your appetite when fasting.

Try to keep the one meal at around 500 calories from real whole foods.

So no sugar, junk food, processed food, high sodium, refined grains, etc…

You shouldn’t be eating anything heavy the day after your cheat day. Anything too salty will cause you to hold onto even more water weight.11

I’ll usually have a vegetable smoothie the day after a cheat day: Kale, spinach, blueberries, avocado, and maybe some other veggies or low-sugar fruits.

There’s a lot of fiber and nutrients in a veggie smoothie. This makes you feel fuller without a bunch of junk calories or bad carbs.12

How long does it take to get rid of water weight after a cheat day?

As long as you get back on your diet plan, you should be able to flush out the cheat day water weight in 1-3 days.

A lot will depend on how much indulgence went on during the cheat day. Also, if you fasted the day after, worked out, and got right back on your diet.

Weighing yourself and seeing the scale go up after a cheat day can motivate getting back on track.

But I’ve also seen some have the scale go down after a cheat day. They triggered the whoosh effect and busted through a plateau.

Who shouldn’t fast after a binge?

If you have a history of an eating disorder, then it’s best not to fast after a cheat day or binge.

Binging then fasting can start or trigger an eating disorder. Now, this should definitely be avoided. 

You shouldn’t beat yourself up for having a cheat day or meal. It’s always best to get back on track.

If you’re worried about developing or restarting an eating disorder, then don’t fast. So it’s best to start eating healthy again.


Following a cheat day, it’s a good idea to have a fast the following day. You can even use a cheat day to jumpstart a 3 day fast or even a 7 day fast.

Whether for part of the day or the entire day, you’ll burn off some of the glycogen from the high influx of carbs. This will help to flush out the water weight.

It’s best to keep your calories and carbohydrates low to flush out water retention. Fasting can help speed up this process, while drinking coffee or tea may make it easier to get through your fast. 

If having an OMAD day, try to stick to 500 calories for your one meal and eat from real whole foods.

Get back on track as soon as possible to lose the weight gained from your cheat day. If you have a history of eating disorders, fasting is not recommended.

Now that you know having a cheat day isn’t a bad thing, it’s essential to know not to stretch it into multiple days.

That’s when the pounds start packing on, and all your progress will be thrown out the window. And then follow it up by fasting the next day to undo “the damage.”