Keto Cheat Days | Can Cheating Knock You Out of Ketosis?

Keto Cheat Days
How To Handle Them And Avoid Future Temptations

Keto Cheat Days

I used to go through diets more often than I bought new runners.  One of the main reasons for all the failed attempts is that cheating the odd day was a bit naughty but not detrimental in the short term.

Sure, how bad could a slice of pizza be?

The problem in doing this while you’re on the keto diet is that you can quickly be kicked out of ketosis.

This is reversible and probably won’t completely mess up your fat burning goals, but there are good and bad ways to have a keto diet cheat day.

Ultimately, you shouldn’t be asking “can you have a cheat day on keto,” but rather “how do you handle cheat meals?”
Even though I’ve been doing keto for 5 years now, I still have moments of weakness at parties and especially around Thanksgiving, thanks to my mum’s cooking.

But, I have worked out ways to handle these small moments.
And I will share them all with you now.

Will A Cheat Day Throw Me Out Of Ketosis?

Yes, it is absolutely possible to be kicked out of ketosis if you suddenly take in a load of carbs. When this happens, you basically have to start the induction phase over again. (More info about the induction phase here)

Before you start to panic though, it’s not going to take as long as when you first started with this healthy lifestyle change. Unless, of course, you’ve gone on a total carbohydrates binge and loaded up on sugar with tons of treats.

woman thinking about something

I can say from my own experience that being thrown out of ketosis is worse than seeing a spike in weight watchers points on your chart.

Your body will have switched back into a metabolic mode that you want to avoid, and it will take some work to fix this.

At the same time, when you get as much experience in dealing with these moments of weakness, you’ll find a process that will quickly resolve it. 

First, though, let’s look at some numbers.

How Many Carbs Can Get You Out Of Ketosis?

Carb foods on the table

For most people, a keto meal plan (see more) will aim to average about 30 g of net carbs per day to stay in ketosis. On some higher intensity workout days that might increase to 50 g or a little more.

Generally speaking, you would aim to get below 50 g of carbs during the induction phase, but that doesn’t necessarily mean that this is the cutoff point where you would be kicked out of ketosis.

While I don’t have scientific evidence, I believe that going above 100 g in a single day will almost definitely kick you out.

Effects Of Cheat Meals On The Keto Diet

woman sneaking some food in front of the fridge
  • Takes You Out Of Ketosis - The first and most obvious of all the side effects of a cheat day is that your metabolism will abandon ketosis. When your body produces very little glucose, it switches to ketone as an energy source. But because glucose is a preferred and more easily accessible fuel, the human metabolism will always favor it. As a result, even just the one carb binge can disrupt things significantly to your disadvantage.
  • Stalls Your Weight Loss - Weight Loss is generally the primary reason to be on the ketogenic diet.With planned out recipes that target a specific dietary macro combination, you can keep burning fat for a long time. But as soon as you switch back to glucose as fuel, you will immediately find this stalls your weight loss and will quickly result in weight increases as your glycogen reserves will be replenished.
  • Spikes Your Blood Sugar - If your body isn’t used to processing carbs and the resulting blood sugar spikes, then this can be quite an upset.
    A lot of people I know use this diet to treat type 2 diabetes. Less blood sugar means less reliance on insulin that you might be struggling to produce. If you get these sudden spikes that you’re not used to, then it can have a very negative effect on your overall health.
  • Slows Down Or Reverses Your Fat Adaptation - Also commonly referred to as keto-adaptation, this is what we call the body’s ability to adapt to using fat as a primary source of fuel. One source is fatty tissue stored in those love handles that you want to get rid of. But even once you’re nice and lean, you’ll be getting fuel from dietary fats. High-carb breakouts will at the very least slow down this process, and you will have to work on reprogramming your metabolism.
  • Increases Your Water Retention - This is something that surprises most people. But what will happen when you binge on carbs is that your liver and muscles will build up some glycogen reserves. And every gram of glycogen binds to 3 grams of water. The result is that within a short space of time you can retain several pounds of water. The good news is that you can quickly get rid of it again.
  • Increases Hunger - Most high-carb snacks are very easily absorbed by your digestive system. This is particularly the case for sugar which are the least complex carbohydrates available. By being able to absorb these parts of your food so quickly, you will feel hungry a lot sooner than you might expect. Compared to healthy fats which can take several hours to fully break down, many types of carbs will leave you feeling hungry within an hour.
  • Causes Cravings - Another unfortunate one of the more common side effects of cheating is rejuvenating sugar cravings. Sweet treats used to be my biggest weakness, and I would crave them from the moment I got up. That 3pm slump could only be solved with a blood glucose spike, but keto did solve this for me. Any time I have a breakout, these cravings return, and I have to overcome them all over again.
  • Makes You Gain Weight - It always surprises me how quickly I register weight gain after breaking with the rules. See, unless your indiscretion is followed up by a very long run or some high-intensity training, you will see those excess carbs either refill glycogen reserves (see point 5 above) or stored as fat. Basically, your metabolism will never waste carbs by just flushing them out. It’s a safety mechanism that evolution has created to protect against starvation.
  • Keto Flu - Keto flu during the induction phase is not a pleasant experience. No matter how much you’re prepared, you will suffer from some not so nice symptoms that really do feel like mild flu. After a breakout, you can drastically swing from ketone as fuel to glucose.  But the swing back to ketone is not as sudden and drastic. The result is that even if you go straight back to your keto compliant recipes, you are likely to have some of these symptoms reappear.
  • Insomnia - The sudden blood sugar boost can have a profound impact on your sleep, which most people call "keto insomnia". If you really want to see this in action, then just give some kids or toddlers a few treats late in the evening. That sugar rush will make them hyperactive and falling asleep can become quite an issue. For adults, the same physiological processes are triggered, and you can quickly find yourself laying in bed with your eyes wide open.
  • Fatigue - Once that sugar high is gone again, you can quickly start feeling absolutely drained. Because of your sudden boost of easily accessible glucose, you will struggle to get enough fuel from fat. Unfortunately, our metabolism favors glucose and will remain in that mode because of the easy access. However, when you immediately withdraw the glucose, you will struggle to produce enough energy to keep you going.
  • Brain Fog - This is essentially the neurological equivalent of physical fatigue. You struggle to concentrate on a task and will be easily distracted, and it all ties back to being kicked out of ketosis. The reason is that ketones are an excellent source of brain fuel and when you’re suddenly relying on glucose again, but not following up with more carbs after a cheat day, then you will find it difficult to think straight.
  • Bloating And Intestinal Discomfort - Many high-carb foods are also rich in fiber. By taking on too much fiber, especially the insoluble type, you can quickly become bloated and constipated. This isn’t something that has happened to me after having a little breakout episode, but friends of mine have reported this issue. Getting back on track is the best thing to do to avoid any extended periods of bowel issues.
  • Makes You Feel Guilty - Personally, this is what I struggle with the most. I know how much of a sugar addict I used to be and having these mishaps just makes me feel like I’m not strong enough to stick with my new lifestyle. Once I get back into my routine, I quickly find that my body will forgive me, but it’s a difficult one to deal with.

If you are keeping diabetes at bay with your low-carb or keto diet, cheating is generally a bad idea. When you eat carbs, your blood sugar can spike to dangerously high levels. Every time this happens you increase the risk of long-term complications like blindness, dementia, amputations, etc.

Jennifer Calihan

Now, let me introduce you to my weak points that lead me to break the rules.

The 6 Main Reasons Why You Cheat

a woman thinking about cheating on Keto Diet

There are probably much more than these, but this is a personal collection from my own experience. 

Whenever I have an unplanned weak moment, I highlight it in my food journal so that I can go back and analyze it later.

  • Peer Pressure - Being the odd one out when you go to a party or for a meal with friends isn’t always easy. Dissecting a menu for carbs or turning away food at a dinner party just seems to raise eyebrows, followed by comments like “just eat it and worry about it tomorrow.” It takes a lot of willpower to avoid breaking under that pressure, and it’s happened to me on quite a few occasions.
  • Politeness - Imagine being at a party and the hosts have gone through a huge effort to create a lovely selection of food. While it seems to be perfectly acceptable to turn stuff down because you’re vegetarian or vegan, doing so because you don’t eat carbs almost sounds like a bad excuse. And you probably don’t like asking about detailed recipes and ingredients, so out of politeness, you end up messing with your diet.
  • Impulsiveness - If you tend to make decisions on a whim, then this is something to be very careful about. Especially if you’ve had cheat days before that you managed to fix a few days later. Sure, what’s the worst that can happen, right? But impulsively binging on sugar and carbs can become a problem when your body isn’t used to processing those glucose spikes, so make sure you think before you act.
  • Failure To Manage Cravings - I found this especially difficult when I first started. I loved muffins and certainly couldn’t pass a Dunkin Donuts without popping in for some. It took me a long time to get over those cravings, and it wasn’t until I found some great keto recipes for treats that I was able to satisfy cravings without messing up my plans. If you have a weak spot for treats, then learn how to make some with no carbs.
  • Bad Meal Planning - There’s probably no other diet that is more difficult to map out. Vegetarians just remove meat, and vegans remove all animal products.
     But planning out meals in a way that removes practically all carbs is very difficult in a world where the majority of foods are packed to the brim with carbs.
    So, make sure you spend extra time on your planning.
  • Incorrect Understanding Of The Keto Diet - When you’re starting out then the best thing you can do is stick to meal plans put together by people that have successfully implemented this lifestyle change. You can get some recipes on our website, or alternatively, you should consider one of the meal delivery plans we have reviewed. They are the most foolproof way to make sure you avoid the wrong combination of dietary macros.

How To Get Back On Track:

woman doing cardio workout outside

The first thing to do is not panic and certainly don’t just jack in the entire diet.

The good news is that with just a few simple tricks you can be back on track with your goals and learn from this lesson.

  • Go Back To Eating Keto-friendly Foods - After a carb breakout, the worst thing you can do is just continue and give up on your new lifestyle. The chances are that you fully understand the benefits from your own experience.  So, after beating yourself up, just go back to your regular meal plan. This is the one that has been working for you and was fine-tuned over months of successful results. This might still result in a couple of days of brain fog and other common symptoms described above, but you’ll speed up the process to get back to ketosis.
  • Go On A Cleanse By Doing Intermittent Fasting - Intermittent fasting is one of those things that sends shivers down people’s spine. Mainly because you might think that this involves starving yourself for a week or longer. While some people go to these extremes, most will actually just go for a day or two, or even just a half day at a time. The result of fasting after a breakout is that you will get through all the glucose and glycogen very quickly. In some cases, this can bring you back to ketosis in less than 2 days.
  • Don’t Let Your Cheat Day Turn Into A Cheat Week Or A Cheat Month - I’ve mentioned before that I don’t stick to keto permanently, but rather alternate by spending 3 months in the summer on a less stringent plan. But if you’ve spent a day at Dunkin Donuts and managed to get through a huge plate of pasta, then don’t use that as an excuse to continue. As fast as you lost all those pounds, extending to a cheat week or month will quickly pile them on again. And that can be even more demoralizing.
  • Understand What Triggers Your Cravings - I advocate that everyone should keep a food diary and also comment on things like what you found tough on a given day. My own diary is full of notes like “really struggled with energy after 3-hour vendor meeting at work” or “gym performance was down.” By writing these down, you will be able to figure out whether there are certain things you can be doing, like adding snacks on days when you know you’ll be busy. If you can reduce your chance of cravings, you’ll reduce your risk of mishaps.
  • Analyze Why You Cheat - This requires total honesty with yourself. After you’ve devoured a Hershey's bar and washed it down with a can of soda, ask yourself why you did this. Maybe you have some stress in your life or other psychological triggers. Or maybe it’s just being low on fuel and not having the right snack plan to keep you going. Keto requires full dedication, and by finding out what caused you to give in to temptation, you can learn from those situations and avoid them in the future.
  • Manage Your Hunger And Cravings - For me, it’s always been an easy option. I got hungry in the afternoon, and I knew I wouldn’t have dinner until I got home in the evening. This was usually after 6pm, so what could the harm be in an afternoon trip to the deli with a pitstop at Dunkin Donuts (I know I keep mentioning this, but I really did have an addiction to them). Instead, make sure you have a water bottle with you at all times. Many times, hunger is just a sign of dehydration. And also create a list of snacks you can eat and find some good supplements that will boost your energy.
  • Do A Fasted Cardio - This is one of my favorites. The morning after I know I’ve taken on too many carbs I either get up really early or skip breakfast. Then I go for a 5k run at a moderate speed just to get some cardio in. This will burn through all the glucose and glycogen that I likely added the day before. As a result, I’ve sometimes even not noticed any switch from ketone to glucose and back again.
  • Forgive Yourself - I have yet to meet someone who hasn’t had a keto cheat meal. Going to a party or wedding, or surviving Thanksgiving without your mother’s pies is not always going to be possible. When it happens, don’t beat yourself up.  Understand that it’s normal as long as this doesn’t happen on a weekly basis.
  • Take Supplements Like Exogenous Ketones To Get You Back Into Ketosis - I take these all the time whether I cheat or not. Once you have gone through the moments of disbelief over what you’ve done, just head for your supplements and get on with it. Exogenous ketones are the best as they will keep your brain clear and working at full throttle.

Do not punish yourself either, or let guilt torture you. Just because you didn’t manage to follow your diet to the letter, doesn’t mean that all your progress is lost and that your efforts were in vain.


Cheating The Proper Way On A Keto Diet:

keto diet foods on the table

Now, if you’re planning a vacation, or know you’ll be in a situation where it’s difficult to say no, then just plan ahead a little and make it a bit easier for yourself.

  • Follow The Cyclical Keto Diet  - I’ve mentioned above that I have 3 months a year where I take some time off. Not to gorge on carbs, but just to take a break and enjoy some food I used to love (except Dunkin Donuts). I usually go on vacation in the summer, and that allows me to be more flexible when eating at nice restaurants or having a few beers. More about the cyclical keto diet here.
  • Cheat With Keto Friendly Food Or Low-Carb Snacks - This is a lot more difficult, but if you tend to break under pressure of a craving for some treats, then check out the many snack options that are delicious and still support your efforts. You’ll be surprised how many of them will actually take care of those cravings. Our favorite one so far has been Keto Kookie, you can check them out here.
  • Cheat With Small Portions - This is important. Rather than eat an entire bag of chips or half of your mum’s pumpkin pie, just take a few mouthfuls and write down what you had. Once you know how many carbs you went over your allowance, you can work out what you need to do to get rid of the glucose quickly.
  • Time Your Cheating - Cheat After A Meal Or Later During The Day - This might seem counterproductive, but later in the day is better when it comes to having a breakout. The reason is that you’ll be heading into a fasting period where you will still burn through some of that unwanted fuel.
  • Cheat With Added Fat- Keeping your fat intake high will be important not to completely mess up your metabolism. You can add some coconut oil as a healthy option, and this will mean that there’s enough fat available when you’re back in ketosis.
  • Cheat With Your Favorite Food For Less Guilt - We all have our favorite dishes, and if you’re going to break from the rules, then stick with cheat meal ideas that will really give you full enjoyment. Don’t just pick something random that you might not even end up liking. For me, it’s my mum’s pumpkin pie.
  • Cheat Before Or After Working Out - I would generally recommend before, as you can always turn up the power during the session to get rid of more of that excess glucose. Do some extra sets or add an extra 20 mins on the bike to wear yourself out a bit more than normal. (More about exercises here)

Basic Intermittent Fasting - Eat all of your meals in a day within a 6-8 hour time frame. An example would be 10 am to 6 pm and fasting for 16 hours between.

Dr. Isaac Jones

Frequently Asked Questions:

1. Are Cheat Days Good For You?
​No, keto cheat days are not good for you in the sense that they will mess up your goals.

But because keto cheat recovery can be very fast, the downsides can be reduced with the right actions.

2. What Happens If You Cheat On Keto?
​When you cheat on keto, you can be kicked out of ketosis if you gorge on too many carbs.

Dependent on what your keto cheat meal was, this can happen in less than 24 hours and take 1 to 4 days to rectify again.

The general idea is for a better-balanced diet with fewer calories spread out over multiple smaller snacks and dinners.

3. Can One Cheat Day Make You Gain Weight?
​Yes, one cheat day can make you put on some pounds as you will start to restore glycogen reserves.

However, what’s most likely is that you hit a keto cheat day plateau, where previous weight reduction levels off for a few days.

4. Will One Cheat Day Ruin Ketosis?
​Yes, one cheat day can ruin ketosis, but this will be an easy thing to fix if you take immediate action.

Follow the above tips straight away, and you’ll be back in business in no time.

5. How Long Does It Take To Get Back Into Ketosis After A Cheat?
​It usually takes between 1 and 4 days to get back into ketosis after a low carb diet cheat day.

This can vary and depends on how committed you are to taking immediate action to resolve the problem and how bad your breakout was.

Final Conclusion

At this stage, you should have a full understanding of why you should avoid excessive cheating but still embrace it every once in a while. The above tips will help you plan it better and also limit the amount of recovery time.

Whether that’s intermittent fasting or hitting the gym hard with some ketone supplements, you will work out a solution. Within just a couple of days, you’ll be back on target and better equipped to stay in ketosis.

If you have some extra tips, then please let us know.

woman thinking about Keto cheat days

About the Author

Ryan is a personal trainer, athlete, health enthusiast, and entrepreneur. He is researching and expanding his knowledge about the ketogenic diet. He spends most of his time writing content about his new learnings of the ketogenic diet and shares it on Ketogenic Supplement Reviews. You can find me on: Facebook, Twitter and Pinterest.