Eating too much protein on the keto diet (a high fat, low carb diet) is a big concern for many people who are thinking about or have just started the ketogenic diet. (Side note: If there’s interest to learn more about the keto diet, the Body Reboot book is an excellent place to start.) After all, ketones come from fat, so it’s important to eat fewer carbs and protein, right? That’s not necessarily true! Many researchers have found that carbs are what mainly interferes with ketosis, so that’s why it’s vital to watch out for hidden carbs. However, protein shouldn’t affect ketone levels, but it’s still important to test ketone levels either via a stick or blood to see if a body is still in ketosis.

Currently, there is a huge myth that claims too much protein is bad for staying in ketosis because it goes against keto’s weight loss benefits. Many sources believe that too much protein can also cause gluconeogenesis, but Perfect Keto says that that’s just not the case:

This myth has since been disproven. However, there are plenty of articles published online stating this false claim, so Perfect Keto would like to explain how GNG really works on ketosis.

Gluconeogenesis (GNG) is a metabolic pathway that allows your liver and kidneys to make glucose from non-carbohydrate sources.

The word gluconeogenesis has three parts to it:

Gluco — coming from the greek root glukos – literally meaning “sweet wine.”
Neo — “new”
Genesis — “creation”
So a great way to think about it is this is how your body creates new sweet wine for your body. This process is special because it’s the creation of glucose from anything but carbs.

Your body takes compounds like lactate, amino acids (protein), and glycerol to manufacture glucose when there are no carbs around.

This may seem like a problem when you’re trying to run on ketones instead of glucose,  but the truth is gluconeogenesis has an incredibly important purpose — and no, it doesn’t harm ketosis.

Some people tout that “you don’t need carbohydrates to survive,” which is only partially true.

To clarify, you don’t need to eat any high carb foods to survive, but make no mistake — your body needs glucose and glycogen to keep you healthy (even on ketosis) and it will get this via survival mechanisms like gluconeogenesis.

Bjarte Bakke, an author on Diet Doctor, agreed with the majority of the keto community who believed that you should avoid eating a ton of protein, so he decided to run a few experiments on himself. For ten days he gradually upped his protein intake, and he was pleasantly surprised when he didn’t get knocked out of ketosis! His findings convinced him that too much protein isn’t a bad thing, but it’s still essential to test ketone levels just in case.

A while back I found out I’d been lying to myself for years – I wasn’t really in ketosis. To understand why, I did an experiment and learned that I’d been eating too many carbs and possibly too much protein.

I immediately reduced my carb and protein intake to maximum 20 and 60 grams per day respectively, and boom – straight back into optimal ketosis.

But I didn’t love eating just 60 grams of protein. To find out how much more I could eat AND remain in optimal ketosis, I did the above protein experiment.

From this latest experiment, I’ve learned that I can likely eat 80-130 grams of protein a day for weeks, and possibly for way longer, without dropping out of optimal ketosis.

So, for me, the key to optimal ketosis is to restrict the intake of carbs to less than 20 grams of carbs a day.

Bakke also mentions that each person is different, and if you’re trying to lose weight you may not want to eat a ton of protein, but that doesn’t mean it needs to be significantly reduced.  

But as this post indicates, I can eat significantly more protein and remain in optimal ketosis. Can you?

That depends.

If you, like me, are a 36-year old insulin-sensitive male, who weigh 152 pounds, exercise for 10-15 minutes five times a week, and have no history of obesity or diabetes, then possibly yes.

However, if you’re overweight and/or have high blood-sugar levels, then possibly no.

If you too want to eat more protein AND be in optimal ketosis, here are two things you can do:

Exercise more.

Find your daily-protein limit for ketosis

Via Diet Doctor

Keto Summit seems to think that protein can knock you out of ketosis because the body turns extra protein into glucose, but as you just read above, that’s not what  Diet Doctor of Perfect Keto believe. Keto Summit recommends using the below formula to determine how much protein a person needs to eat while on keto:

Eating too little protein can mean you lose too much muscle when you lose weight. But eating too much could cause your body to turn that excess protein into glucose and thereby knock you out of ketosis.

There’s not a general consensus on this issue…

But below are some good guidelines to follow when determining how much total daily protein you need on Keto.

Calculate Your Protein Needs On Keto Using This:
Figure out your body fat percentage.
Multiply your body fat percentage by your weight. This gives the amount of your fat.
Your lean body mass = Your weight – Your fat amount (from above).
The amount of protein you should eat = 0.8 * Your lean body mass (in lbs)
If you use metric units and prefer Kg calculations, then multiply your lean body mass in Kg by 1.8.

Keto Vale adds their two cents to the topic by mentioning that protein is a good thing because it can help with muscle mass, but it’s still a good idea to get a good idea about how much protein to eat by measuring your Lean Body Mass (LBM), which the author explains below:

It depends. There isn’t a straightforward answer to that question as it depends on various factors such as your body composition (and lean body mass in particular), your goals, your age, gender and your activity level.

Very low carb diets, such as the keto diet, are actually protective against muscle loss, given that adequate protein is consumed. This is good news, in case you want not only to lose weight, but also to improve body composition.

Let’s face it: you most probably want to look good in a swimming suit, and not just hit a specific number on the scale.

In order to achieve that, you need to, most importantly, lose fat, but also preserve your muscle mass. With sufficient protein and a good workout routine, you can actually gain muscle even when dieting (although at a slower rate than when eating at a surplus, or what bodybuilders often refer to as “bulking”).

For the purpose of losing weight, you should be consuming between 0.68 to 1 g per pound (or 1.5 to 2.5 g per kilogram) of Lean Body Mass (LBM), not total body weight.

Lean body mass (LBM) is your total body weight minus your fat weight. In other words, your LBM is the amount of weight you carry on your body that isn’t fat.

Metro is one of the naysayers who believe, based on what they’ve heard from some keto dieters, that protein can kick you out of ketosis, and if given the opportunity you should snack on fat as opposed to protein.

If you’re sticking to the plan and working out regularly, you still might not be reaping the benefits keto is supposed to offer (lower blood sugar levels, weight loss, more energy). Well, it could down to how much protein you’re consuming. People don’t achieve nutritional ketosis because they’re eating too much protein. And that’s because protein has a moderate insulin-stimulating effect which can interfere with ketone production in the liver if eaten in excess. Keto diets are moderate, not high, in protein. According to Virta Health, ‘most healthy individuals require between 1.5 and 1.75 grams of protein per kg of “reference body weight” to maintain lean body mass and function during a ketogenic diet. Intakes above 2.0 g/kg reference weight show no additional benefit’. But the common mistake many keto-followers make is eating well above that amount – choosing to snack on protein rather than fat.

So what do you think? Is consuming too much protein a bad idea or will it stall your weight loss? Perhaps if you’re worried about your body composition having extra protein shouldn’t hurt, but if you want all of the benefits of being in ketosis, it might be a good idea to monitor your ketone levels. From the sound of things every person is different, so it’s best to remember that when reading another source that says that overeating protein will work against you!

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Sources: Diet Doctor, Perfect Keto, Keto Summit, Keto Vale, Metro.co.uk