So you had your weekly cheat day, an unplanned meal, came back from vacation, or wondering if you were kicked out of ketosis for eating X or Y…
Will this kick me out of ketosis? The only real way to be kicked out of ketosis is by consuming too many carbohydrates. There are no specific foods, sugars, or supplements that will cause you to be kicked out of ketosis for any prolonged period.
When people first start a ketogenic diet, this is quite the common question, and in this article, I'm going to attempt to explain why something will or won't kick you out of ketosis and how to get back in, so you're feeling optimal again.
How Ketosis Is Established
To understand why something will kick you out of ketosis, I must first explain how you enter ketosis.
For starters, ketosis is a metabolic state, not a list of foods. This metabolic state is achieved primarily by restricting carbohydrates from the diet.
A metabolic state is merely referring to the breakdown of food and its transformation into energy. In the case of a ketogenic diet, this energy (food) converts into ketones.
Our brains need ~120 grams of glucose (sugar) per day to function.1 When our brain doesn't have enough glucose, the only alternative energy source our brains can utilize are ketones.In short, our brains require glucose for energy. When glucose is restricted, the body will make ketones to feed it.
Therefore, the brain will either be using glucose or ketones for fuel. To know if you're still in ketosis, or if you've been kicked out of ketosis, is a matter of figuring if your brain is getting energy from glucose or deriving them from ketones.
The Does X Kick Me Out Of Ketosis Section?
Insulin has been getting demonized on and off for decades, but that's beside the point. So does an insulin spike kick you out of ketosis? Kind of.
It would be best if you kept in mind that you may be fluxing in and out of ketosis throughout the day, but it's nothing to worry about.
In the case of insulin, it's cleared from the body at such a quick rate that even if you were knocked out of ketosis, it would only be a short period.
There was a study where a male participant had fasted for 50 days and was producing ketones in the 14 mmol/L range (0.5 mmol/L or higher is considered being in nutritional ketosis). The fasting participant was then subjected to an insulin tolerance test by administering insulin intravenously at 0.1 iU/kg.
As shown in the graph, ketones dropped in the 30 minutes following the insulin but shot right back up.
Keto and “too much protein.”
I don't know where this myth started that too much protein would magically turn into a chocolate cake (though that would be nice) and spike your insulin, thus kicking you out of ketosis.
Well, as you may have read from the previous section, EVEN if protein caused an insulin spike, it would be nothing to worry about. Furthermore, the amount of insulin that would be released relative to insulin directly injected into your veins pails in comparison.
What about glucoconeosomethingandsuch that I've heard about?
Gluconeogenesis (GNG) is the process by which our bodies create glucose from non-carbohydrate substrates (amino acids, lactate, glycerol, etc.).Gluconeogensis literally translates into the ‘production of new glucose.
GNG is a demand-driven process, meaning it only occurs when it's needed.
The other part of gluconeogenesis is that it's continually happening, even on a ketogenic diet. GNG can also occur if you kept protein to minimal levels.
Even though the brain can derive most of its energy from ketones, the brain will always require a small percentage of glucose for fuel. Aside from the small number of carbohydrates you may eat on a ketogenic diet, the rest is created via the process of gluconeogenesis.Ketosis doesn’t stop just because GNG is ocurring. Both ketogenesis and gluconeogenesis can happen simultaneously. 2
What happens if you have sugar on a keto diet? /how-much-sugar Technically nothing happens, so long as you stay at or below your carbohydrate allotment for the day.
Meaning, as long as you're not refilling your liver glycogen, your body will still need to create ketones to provide fuel for the brain.
Does this mean you'll never be kicked out of ketosis, even if you ate straight table sugar? Not always, but similar to spiking insulin, you may flux out and back into ketosis so fast you would never know.
The most critical factor will generally always be your total carbohydrates.
No artificial sweeteners will inherently kick you out of ketosis by consuming them. However, certain artificial sweeteners do have a glycemic index and contain more calories, such as Maltitol.
Non-nutritive (no calorie) sweeteners should generally be safe to consume without needing to worry about being kicked out of ketosis.
This includes sweeteners such as:
- Monk Fruit
What about alcohol?
Keto and alcohol, is that allowed together? You'll be happy to know that alcohol INCREASES ketones.
As long as you don't consume any carbs with your alcohol, as with the case with hard liquor, you shouldn't be kicked out of ketosis.
The same goes for wine and beer. As long as the wine or beer is relatively low in carbohydrates and fits within your carbohydrate total for the day, you need not worry about being kicked out of ketosis.
When alcohol is consumed, the body's priority is to metabolize and clear it from the body before anything else. Alcohol is metabolized into acetyl-CoA, and the body tries to remove the acetyl-CoA by producing more ketones.
Things That Knock You Out Of Ketosis
Based on what we know by now, you can be going in and out of ketosis daily without even realizing it.
However, the only real way to be kicked out of ketosis is by eating enough carbohydrates to do so. How much carbohydrates that is depends on the individual, but usually comes down to:
- Activity level
- Muscle mass
Meaning, the more active and more muscle you have, the more carbohydrates you can generally consume without knocking yourself out of ketosis.
I've seen highly active individuals and other athletes eat upwards of ~150 grams of carbohydrates and still be able to produce enough ketones to be considered in nutritional ketosis.
In fact, at my leanest, while dieting for a bodybuilding contest, I was able to remain in ketosis, eating upwards of ~200 grams of carbohydrates per day.
Kicked Out Of Ketosis, How Long To Get Back In?
There is a myriad of reasons you may have been kicked out of ketosis.
Maybe you like to have a keto “cheat day” once a week with all your favorite carbs, or perhaps a low carb cheat day, but enough to kick you out of ketosis.
How long it takes to get back in ketosis after an influx of carbohydrates or how to get back into ketosis after vacation will depend on a few factors:
- How long you've been on a ketogenic diet
- How many carbs you consumed
- How active you are
Assuming you went off the rails and ate nothing but carbohydrates, by merely fasting for 24-36 hours, you would begin to start producing ketones.
The liver can hold approximately ~100 grams of carbohydrates. Assuming we have refilled the liver, then getting back into ketosis would be a matter of depleting that ~100 grams of carbohydrates.
Since the state of our liver glycogen will determine whether your body produces ketones or not, it's just a matter of time once you restrict carbohydrates that you should be back to producing ketones.
As I've said earlier, your brain needs about ~100 grams of carbohydrates per day to meet energy demands. When the liver is refilled for any reason, the brain will halt ketone production and begin using glucose as fuel until it runs out again.Depending on how many carbohydrates you ate, worst-case scenario, you should generally be back in a state of ketosis within 24-72 hours after restricting carbohydrates.
I did a self-experiment myself to see how long it takes to get into ketosis after restarting a keto diet from a prolonged period of carbohydrate intake.
How Long It Takes To Get Out Of Ketosis
How long it takes for you to get kicked out of ketosis depends on how many and what types of carbohydrates you eat.
Generally speaking, if you consume a large number of carbohydrates from fructose, the potential to get kicked out of ketosis is much higher. Fructose metabolizes in the liver; therefore, it will preferentially refill liver glycogen.
If you're wondering the quickest and easiest way how to get out of ketosis, consume a large amount of fructose from fruits or sucrose, which is half fructose and half glucose.
If you're following a cyclical ketogenic diet, consuming fructose before the weekend carb load is tactic often used to shift the body back into a state of burning glucose for fuel.
The only real way to be kicked out of ketosis is by consuming too many carbohydrates.
There may be foods that take you out of ketosis for a short period, but not long enough to matter in the grand scheme of things.
Worst case scenario, even if you binged for an entire weekend on nothing but carbohydrates, you can be back into ketosis within 24-36 hours if you fasted.
Or, get back on track with the keto diet you were following before you fell off or took a break, you should be back into ketosis within 24-72 hours.