Grandma is coming to town. She’s missed you dearly. So much so that she’s taking you out to Italian tonight.
No avocados or almond butter for you. You’re eating pizza and pasta tonight.
You’re insulin is probably spiking reading this. You’re…. breaking keto. (unless you make this keto pizza!)
What will happen?
Getting kicked out of ketosis sounds awful. Like getting kicked out of a party. Or getting kicked out of school.
But is it really that bad? Can we hop right back in after a “cheat day”? Or is our keto mission derailed, along with all weight loss and well-being?
In this post we’ll look at the science of eating carbs while in on the keto diet. And we’ll answer the burning question… what happens when you get kicked out of ketosis.
Don’t worry, it’s not as bad as it sounds. We’ll even show you some tricks for getting right back into ketosis after indulging.
Why getting kicked out of ketosis is not the end of the world.
You don’t have look far on low-carb forums to find full blown freakouts from people getting kicked out of ketosis.
“... and then I found it had MALITOL in it. I ATE CARBS. I’m not gonna be able to sleep tonight. My body just can’t handle carbs like it used.”]
Keeping a keto lifestyle is a lot of work. We know first hand cheating can make you feel like failure. But is it really a major set back?
To answer that, we first need to understand the difference between ketosis and fat-adapted.
Ketosis may own the name, but fat-adapted is the state we are all striving for.
Fat-adapted is not the same as ketosis. You can be fat-adapted, but not in ketosis.
Keto-authority Dr. Timothy Noak’s explains:
“Fat adapted means that you’re whole body is adapted to burn more fat. From your brains to your muscles, your liver changes slightly. It takes about 6 weeks.
We would be able to measure that, we would show you burn much more fat and that you conserve carbohydrates.
If you become fat adapted, you burn an enormous amount of fat during exercise. Even up to quite high intensities. So that would be fat adaptation. You’re able to run at 80 to 85% of your maximum, while still burning a predominance of fat. And in all textbooks, we would say that’s impossible. And it is impossible if you are carbohydrate-adapted. Because once you go over 60 to 65% of your maximum, you will be burning primarily carbohydrates.”
When you become fat-adapted, you have trained your body to run primarily off fats. You burn fat freely and conserve carbohydrates. This is no small feat – remember you’ve been running off glucose almost your entire life.
Changes were required to your cells, mitochondria, and liver to make this happen. A oven-toasted bagel ain’t gonna take you back. Not even a fat slice of pecan pie. No, it would require a full-return to the carb life (and who wants that!?) to spoil the benefits of becoming fat-adapted.
Much of the keto diet’s magic is due to fat-adaptation. The fat-adapted state person can:
Stay full between meals. This reduces cravings and thus excess calories.
Burn body fat and loss weight. My being able to more efficiently oxidize our own body fat for energy, we can lose weight.
- Improve athletic performance. The body can store far more energy in fat than as glycogen. This is why you’ll see marathon runners slurping those gooey starchy packets on the trail. Evidence is showing fat-adapted athletes can outperform their carb-hooked competitors.
As long as the fat-adapted state is not compromised, many of keto’s benefits will continue.
Now let’s look at ketosis.
Ketosis means ketones are being produced in the liver from fatty acids. That’s really all there is to it.
This happens when liver glycogen (stored glucose) runs low. The body goes into starvation mode and turns on an alternate fuel source.
Fasting or eating a high-fat, low-carb diet – what we call the keto diet – will start this process within a day or two.
It turns out there are some unique advantages to this state. Here’s Dr. Noaks again:
“Ketone bodies are remarkable because they are the only type of fat that is water-soluble. And so they circulate in the bloodstream and can be used as a fuel by the muscles and the brain.”
Our body is actually constantly making ketones. You probably have some after waking up after a long slumber. If that’s so, then what is really is ketosis?
As carbs are restricted, ketone levels build up in the blood. The inventors of the ketogenic diet measured many of their subjects and decided that concentrations between .5 mMol and 5 mMol. It has stuck to this day.
It would be easy then to think, the higher the ketone level, the better.
It’s not that simple.
In the induction phase you produce a high quantity of ketones. Then as you become fat-adapted your ketone levels will begin decline. This is because your muscles learn to run off free fatty acids, and no longer need ketones for fuel. The brain switches to run exclusively off ketones.
These are all good things. You will be burning fat at a higher rate. Your brain will be supercharged on ketones.
But that darn blood meter will be showing lower levels. No bragging points for you.
Ketosis is a transient state. It’s easy to get in, and even easier to get out. Down a glass of MCT oil powder and you’ll be deep in ketosis. Eat a pizza and you’re out.
You can fall out of ketosis by exercising. Good ole’ stress can do it to. This is because raise insulin, which lowers ketones production. Ketosis is a fickle thing.
Having high ketone levels can be a good thing. We have little scientific evidence to prove it, but many claim high ketone levels enhances their mood and boosts their brain. A carby meal can put an end to that and bring on the “fog” keto-ers dread so much.
Our advice is to go by how you feel. The ketone meter can become an obsession, a source of joy or shame based on the day’s reading. We think this is missing the point.
Forget the scary sounding “getting kicked out of ketosis” and focus on what really matters… long-term fat-adaptation.
The bottom line: a carb meal will kick you out of ketosis, but it will not kick you out of fat-adaptation. Think of ketosis as number on a screen, a point-in-time read, while fat-adaptation is long-term change in your metabolic function.
The longer you have been in a fat-adapted state, the less you need to worry about getting kicked out of ketosis. But if you are just starting out, you’d be wise to save those cheat days for a rainy day!
What happens when you get kicked out of ketosis?
You lick your lips as that last bite of pasta goes down the hatch. Fettuccine alfredo, your favorite. Hey, at least you a healthy dose of fats in that cream sauce.
As those sweet carbs hit your system, blood glucose levels rise, and the pancreas secretes insulin. Insulin stimulates enzymes that stores blood glucose in the liver as glycogen.
You are now in the “fed” state. And ketone production has ceased (boo!).
The carbs you take in will stop ketone production until they're used up, or stored away in muscle. The good news is your liver can only store ~100 grams of carbs in glycogen. When carbs are removed again, your blood glucose falls, and the liver signals the release of the glycogen. This takes 12-16 hours depending on activity level. Once glycogen is depleted, ketogenesis resumes.
The return to ketosis is no different than when starting the diet. It just happens a lot faster.
What are the downsides to getting kicked out of keto?
While breaking keto isn’t the end of the world, it can make you feel crummy. And we’re not just talking about guilt (which let’s be honest.. there shouldn’t be any!).
Here are a few of the big negatives people report when breaking the diet:
- Carb cravings. Insulin spikes force energy into your cells but can leave other cells in a starved state depending on how insulin resistant you are. Starved cells crazy more… you guessed it… carbs. It can be a vicious cycle that can take keto-ers off the rails.
- Fatigue. Ah the carb crash. Remember those!? Insulin levels can leave you with low blood sugar and
- Brain fog. Those precious ketones make an efficient fuel for the brain. With ketones temporarily stopped, many users
These symptoms vary a lot person-to-person. There are reports of people being bedridden after a single carb indulgence. Remember that keto flu you worked so hard to get over?
Our best advice is listen to your body and understand where you carb tolerance lies.
What about weight gain?
No question the number one use of ketogenic diet is weight loss. It’s power for that is unmatched.
It’s no surprise also the terror when someone breaks keto and declares “oh my god I gained 4 pounds overnight. Jelly donuts… NEVER AGAIN”
A little science lesson is in order.
The glycogen process we talked about earlier does come with a cost. Each gram of glycogen stored requires 4 grams of water.
The majority of weight “gained” by cheating is really just water weight. Remember when you started the keto diet and those pounds magically melted away? This is just that process in reverse.
The good news is glycogen depletion takes less than a day. Those pounds will vanish as quickly as they came.
Can you have carbs AND keto?
What if it was possible to devour your pasta AND stay in ketosis? A delectable meal plus all those brain-boosting ketones? Can you have your pasta and eat it to?
Sounds too good to be true…
But it is. All you have to is bike 110 miles per day for two days leading up to your Italian dinner. Make sure to get at least 6,000 feet of elevation on your rides too.
Kidding aside, our story comes from an personal experiment by Dr. Peter Attia. If you don’t know (and you should know) Dr. Attia, he is a longevity doctor, ultra-endurance athlete, and one of the leading thinkers on the ketogenic diet.
The last day of his ride, Dr. Attia consumed 351 g of fat, 243 g of protein, and 321 g of carbohydrates. That’s enough to make any keto-er cringe.
Yet the following day he tested his ketones and low and behold… 2.2 mMol. Almost what we’d call “deep ketosis.”
His hypothesis was all that riding created a glycogen deficit in his body. All those carbs went to pay off his glycogen debt while the liver was free to keep cranking out ketones.
You don’t have be this extreme to kickstart ketosis. Almost any form of exercise will deplete glycogen and speed the return to ketosis. The higher the intensity, the better.
Cardio interval training or high-intensity circuit training are the best for depleting glycogen stores and accelerating ketosis.
Heck, you could even do air squats in the bathroom before your primo and secondi course. You’d be in good company – Tim Ferriss has been known to do this.
The Bottom Line
Keto is a powerful tool to lead a healthy and happy lifestyle. It is not a game where the highest ketone levels win, or one where carb-indulgers are kicked out and lose.
You goal on the diet should be to feel good and work towards fat adaptation. Carb breaks can be speed bumps along the way and you might feel crummy after. But you can always pick it back up the next day.
And hey, life is too short not to indulge from time to time.
To your health,
Ben & Brandon