A little planning and motivation will help you start a low-carb, keto, or Primal lifestyle, and under normal circumstances, keeping your carbs on the low side is easy. But let’s not create the illusion that it is easy all the time. From time to time, you may get stressed and eat mindlessly. Or, your aunt drops off her blue-ribbon cake that you’ve loved since you were in preschool, and you give in, just this once. Or, you had a jam-packed day and all you can muster to make for dinner is that package of gluten-free noodles in the back of your pantry. The next thing you know, you’ve eaten enough carbs for a week, and you wonder how you’ll get back into ketosis after a carb binge.
The short answer is, yes you will recover from a carb binge. Yes, you will get back into ketosis. As far as how long it will take to get back into ketosis – that depends on numerous factors, that we’ll dive into here. The important thing to remember is, you did not obliterate your goals with one misstep. Especially after you’ve spent some amount of time in ketosis, your body will allow for fluctuations in carb consumption here and there. That’s called metabolic flexibility, which we’ll go into shortly.
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Can You Have a Cheat Day on Keto or a Primal Diet?
Admittedly, I’m not a fan of calling them “cheat days,” for a few reasons:
- “Cheating” implies that you did something wrong and should feel guilty about it.
- Earmarking “cheat days” sends the message that you can eat whatever you want that day with abandon. You’d be surprised how much you can backpedal on your goals in a 24-hour period.
I prefer to frame higher carb meals or snacks as carb cycling or carb refeeding,  which is an intentional higher carb meal to enhance your results; or, frame them as treats, which are planned. That way, the extra carbs are enjoyable, planned in advance, and come with limitations so you don’t go overboard. And, there’s no guilt involved.
So, can you have high-carb days on keto? If you are in ketosis and have a sudden surge in sugar or carbs, your body will burn glucose instead of producing ketones. In order to get back into ketosis, you have to use up the glucose you just consumed, and the glycogen your body just stored.
The concern is whether the transition back into ketosis will be as difficult as you remember from those first days cutting carbs. If you have been in and out of ketosis for a while, you may slip back into ketosis fairly easily because you’ve developed metabolic flexibility . If you’re just starting, you may go through some of the discomfort of transitioning between fueling with sugar vs. fueling with ketones. Your body “remembers” though, and most likely, it will not last as long or be as severe. This article  contains some things you can do if you experience “low-carb flu.”
What Happens to Your Body After a Carb Binge?
So, you decided to give in. First, don’t beat yourself up. It happens. What does your metabolism do with the surge of insulin and carbs? Even a few quick forkfuls can shift you from small doses of quality carbs wisely spread throughout the day to possibly 100 or more grams of pure sugar in one sitting. It’s likely you’ll experience some effects, but you can get past it.
First off, the good news. There’s no carb police coming to take away your keto card. Nor is there any other permanent fate awaiting you. You’ll go about your day a live, generally functional human being. There is no truly long-term risk elevation for that matter. Nonetheless, you’ll likely experience a fair amount of regret for cheating on keto.
- Your Pancreas Kicks Into Overdrive. Within a few minutes, your pancreas starts pumping out a flood of insulin to try to sop up all the excess glucose that’s suddenly rushing through your bloodstream. Remember, while glucose is muscle fuel when it’s in the muscles, it’s toxic sludge when it stays in your bloodstream. Your body knows that and does everything it can to get it out of there. Perhaps you’re feeling flushed, a little high, spastic, anxious, or nauseous depending on how much you ate, how big you are, what your normal carb load is, and how acutely you tend to “feel” the effects of sugar and other substances. Ironically, if you were insulin resistant, you might not even notice these sensations.
- Excess glucose converts into body fat. The gush of insulin now creates a see-saw effect. If your glycogen stores have room, some of the sugar goes into muscles. If there’s no more room, the excess goes into fat cells, where it is stored as fat. In reaction to this quasi-emergency that your brain perceives as a life-threatening stress, the body steps up its efforts to achieve homeostasis by releasing both epinephrine (adrenaline) and cortisol from your adrenals. Your heart starts racing, and you’re starting to feel uncomfortable, maybe even sweating. And we’re still likely within the first hour after you finished off that cake!
- Sugar crash. After a bit more time passes, burnout settles in. That’s called a sugar crash – when all the glucose is gone from the bloodstream and you start to feel sluggish, off-kilter, like the internal circuits are all fried after sparking in a heap of now smoldering wires.
- Your immune system slows down. The havoc that sugar rush set off – the swing of glucose and insulin, the cortisol and adrenaline – they’ve sent your immune system into a tailspin. Research1  has shown that the function of immunity-related phagocytes, the cells that surround and engulf pathogens, is impaired for at least five hours after intake of simple sugars. Free radicals, or damaging oxygen atoms, have their heyday as well within the first few hours after sugar increases oxidative stress2  on the body. Your blood even thickens as a response to the stressors. A hefty dose of sugar can compromise the immune system3  for more than 24 hours.
- Your sleep is disrupted. At the end of the day, you try to sleep it off, but you toss and turn as your heart continues to beat faster than normal. Little surprise there – the old hormonal system is confounding in its interconnectedness. You lay there cursing not just that cake but the entire cultural custom of birthday celebration. As the sun comes up and you roll out of bed, you think you should be done with this sugar business by now. Maybe, maybe not.
How to Recover From a Carb Binge
As bad as this sounds, it could be worse. If you follow a Primal  or keto  lifestyle and the carb overload was just a detour, you’ll come out of this generally as healthy as you were before the flub. You’ll experience the effects, and you may feel them more acutely than you did before you chose the low-carb path. This isn’t a bad thing. Nonetheless, after the dust settles, the worst thing you can end up with is maybe a cold you wouldn’t have gotten otherwise. Your system will realign itself pretty readily. After spending a couple days back on your regularly scheduled program, you’ll be as good as new.
How to Get Back Into Ketosis After Cheating on Keto
So, you want to get back into fighting shape as soon as possible. Here’s what to do:
- Scale back your carbs to where you were before you found yourself off-track.
- Make sure you are getting the correct balance of electrolytes. Read this article to understand why electrolytes are important  while transitioning to ketosis and how to make sure you are getting adequate electrolytes.
- Consume sufficient high-quality fats, especially at first.
- Don’t overdo the cardio . You can ease back into more intense aerobic exercise once you’re fully transitioned.
- Consider intermittent fasting.  You may have an easier time getting into ketosis for the long haul if you time-restrict food intake, which gets your body used to producing ketones.
How Long Does it Take to Get Back Into Ketosis?
You may wonder how long it will take to get back into ketosis after falling off. The answer is, it varies. It depends on how metabolically flexible you were before you started, how insulin-sensitive you are currently, how many carbs you were accustomed to consuming before you increased your carb intake… there are a lot of factors. The vague answer is, it won’t take long to get back. Start now, and you’ll get to where you want to be before you know it.
- http://www.ajcn.org/cgi/content/abstract/26/11/1180 
- http://jcem.endojournals.org/cgi/content/abstract/85/8/2970?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&volume=85&firstpage=2970&resourcetype=HWCIT 
- http://www.ncbi.nlm.nih.gov/pubmed/18469239?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DiscoveryPanel.Pubmed_Discovery_RA&linkpos=2&log$=relatedarticles&logdbfrom=pubmed