BB2019 – Week 4 – Friday – out of Ketosis

Physiological Effects of Getting Kicked out of Ketosis

Ah weekend time . . . when the mind turns to shenanigans. You’re a full four weeks into the experiment and regularly showing ketones. You may have even noticed a lift in brain fog. Excellent. You are probably fat-adapted.

You can be fat-adapted, but not in ketosis. We want the fat adaptation. We measure it by measuring ketone levels.

Fat-adaptation is more important than ketone levels with regard to your longevity. Fat adaptation is the process by which your body’s cells have re-opened the pathways that allow you to use ketones for fuel. Ketosis is a real-time measure of the fuel your body is using. Once you’ve made ketones long enough to get into the fat-adapted state, your body is happy to keep using ketones without losing the ability to use glucose when it hits the system. As mentioned in previous posts, part of this is due to normalizing a healthy insulin response.

Fat adaptation creates metabolic flexibility for you.

Glucose heavy meal? Your body will use up the glucose first then will kick back to using ketones.

Fat heavy meal? Your body will still use up any circulating glucose – which should be minimal – but will then resume making and using ketones.

Protein heavy meal? It depends on how insulin resistant you are. In the absence of circulating carbs (over-simplification), with proper insulin sensitivity, your body will pull apart the proteins and keep making and using ketones. If you have insulin resistance (with or without circulating carbs), your body may treat that protein heavy meal like a carb-rich meal.

What happens to your ketosis when you eat the things you used to enjoy?

Will you wake up with your worst hangover ever? Will you sprout a new limb? Will you gain 20 pounds overnight? What happens physiologically when you break ketosis?

Definitely out of Ketosis

When you eat enough carb to get yourself kicked out of ketosis – and this definitely varies per person based on foods and activity level!! – you may actually put on a little weight overnight. It’s water weight. Once you are back in ketosis this will shed much like it did when you started eating keto. If you carb load regularly without the activity to deplete those carbs though that water weight will give way to fat storage.

Nutritional ketosis and fat-adapted are states not diets. Certain foods help you get into those states and others take you away from those states.

Worst case – let’s say you binge on pasta for a week – you may experience the same carb withdrawal systems you had when you first started: nausea, fatigue, headache, and dry mouth. It’s withdrawal. It’s not fun. What I’ve discovered is that foods I used to enjoy aren’t that great now that I’m adapted. My favorite cracker is no longer irresistible. It’s fine, but the craving I gave into was more of a womp womp. I prefer the memory of the intense cheesy sourdough cracker to the current actual.

It’s kind of like running into your crazy hell-raising teen-aged boyfriend 20 years later. He’s still riding the bike, but his hell-raising seems decided lame. He’s consistent, but your tastes have changed. AKA the man in his 50s who is still trying to pull off a leather jacket he was rocking in his 20s.

Fat adaption is a really big deal. Your cells, mitochondria (powerhouses within the cells), liver, and brain have changed to make this happen. A deep dish pizza isn’t going to break your fat-adaptation. Nor is a chocolate cake. Even a whole one. You would have to return to your carb life to lose the fat-adapted benefits.

As long as the fat-adapted state is not compromised, many of keto’s benefits will continue. And it would take you weeks of dedicated “cheating” for this to happen.

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 reading, while fat-adaptation is long-term change in your metabolic function.

The longer you stay in a fat-adapted state, the less you need to worry about getting kicked out of ketosis. But if you are just starting out, save those cheat days for a rainy day!

So what actually happens:

  1. Carbs hit your system.
  2. Blood glucose level rises.
  3. Pancreas secretes insulin.
  4. Ketone production stops (with enough carbs hitting the system).
  5. Insulin helps liver, muscles, and other organs replenish glycogen levels.
  6. Once glycogen levels are at capacity in organs accepting glycogen (for seriously fat-adapted some of your muscles and organs will stop accepting glycogen – they no longer want much of it), the remaining will be stuffed into fat cells. This is the normal process for carb meals at any time keto or not keto.
  7. When you get back to a carb-depleted environment, the blood glucose will fall signaling the liver to release it’s stored glycogen. This could take a few hours to a day depending on your activity level, 4-12 hours is the norm. Your size and insulin resistance impact the time.
  8. Once glycogen is depleted, ketogenesis resumes. Same as when you first started making ketones, but faster.



  • 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 crave more . . . carbs. It can be a vicious cycle that can take you off the rails. Kryptonite anyone?
  • Fatigue. Insulin levels can leave you with low blood sugar after a big spike which is called . . . a crash. Yep. So the feeling of exhaustion is really a hormonal response.
  • Brain fog. Ketones are your brain’s preferred fuel. The first time I intentionally tested a kick out of ketosis, I had a headache and was definitely relatively impaired. Good to know. Subsequent tests to push out of ketosis have been barely perceptible to minorly irritating.

So a few months in when you’ve let your body know that you’re fat-adapted and you like it, your body will conspire to help you stay fat-adapted. When you want to feast, feast.