Is Too Much Protein Bad for Ketosis?

The keto diet is known for being a very low carb, high-fat diet.

This approach helps you boost your ketone levels and enter nutritional ketosis, which is a metabolic state in which you burn mainly fat (ketones) for energy instead of glucose.

This is the defining difference between the ketogenic diet and Atkins or other low carb diets, which simply reduce some carbs and don’t try to put you in ketosis.

But there’s one more nutrient to consider and many misunderstand its role on the keto diet.

I’m talking about protein.

On keto, you will consume adequate amounts of protein — never less than you need. This macro is one of the hardest to nail down when starting keto due to all the conflicting misinformation about it.

Protein is a building block of life and a necessary component of any diet. It’s crucial for:

  • Healthy brain function
  • Skin, bone, and muscle health
  • Building muscle mass
  • Recovering after workouts
  • Cutting body fat

These benefits promote longevity, prevent injuries and boost your metabolism.

Unfortunately, a lot of ketogenic dieters are worried that eating too much protein might kick them out of ketosis.

Many low carb, high fat advocates believe excess protein can turn into sugar in your bloodstream through a process called gluconeogenesis and knock down your ketone levels. But as you’ll find out, this is only a myth.

In this article, we’ll talk about:

  • Can too much protein be bad for ketosis?
  • 3 reasons why you should eat more protein on keto
  • The best keto protein sources
  • How much protein should you consume on keto?
  • The best metric to measure on keto

Can Too Much Protein Be Bad for Ketosis?

Eating too much protein is one of the biggest concerns for people who are just starting the ketogenic diet.

After all, ketones are produced from fat, so you should keep carbs and protein down to a minimum, right? Not necessarily!

Carbs are the only macronutrient that can seriously interfere with ketosis, which is why it’s important to watch out for hidden carbs and find the carb limit that works for you.

On the other hand, eating protein won’t affect your ketone levels. You can eat high fat and high protein (preferably fatty cuts of grass fed meat) and stay in ketosis.

That’s why many people who transition from keto to the carnivore diet have no problem staying in nutritional ketosis.

But what about gluconeogenesis (GNG)?

GNG is a real and necessary process that is already happening in your body. It’s not the enemy of ketosis, in fact, it makes ketosis possible in the first place.

Surprised? Here’s how it really works:


There is a widely-circulated claim that excess protein is detrimental to ketosis because it causes gluconeogenesis.

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.


On a keto diet, your body uses gluconeogenesis for 3 main purposes:

  • Preventing hypoglycemia.Your glucose levels can never drop to zero, even on ketosis. GNG keeps your blood sugar on a healthy range so it doesn’t fall to dangerous levels (aka hypoglycemia).
  • Fueling tissues that can’t use ketones. There are a handful of cells in your body that can only use glucose to survive, including red blood cells, kidney medulla (inner part of the kidney), testicles and some parts of your brain. Ketones can cover up to 70% of your brain’s energy needs while glucose from GNG covers the rest. The other organs can’t metabolize ketones at all, so gluconeogenesis provides them with enough glucose to remain healthy.
  • Resupplying glycogen stores. You can actually replenish muscle glycogen through the GNG that happens during ketosis — at least if you’re not a professional athlete or participate in competitions. Glycogen is crucial for muscle recovery after workouts.

These functions are incredibly important. If GNG didn’t make enough glucose to cover them, your body could never make the switch to using ketones for energy because some cells (like red blood cells) would die and your blood sugar would drop too low.

This means gluconeogenesis makes ketosis possible.


Now, could you boost the rate GNG if you eat too much protein? Not likely.

GNG is an extremely stable process. It’s not easy to increase it even with extra protein.

Gluconeogenesis (making glucose from non-carbs) doesn’t work at the same rate as carbohydrate metabolism (making glucose from carbs).

When you eat chocolate cake, your blood glucose quickly spikes in response to that sugar.

When you eat extra protein, your blood glucose doesn’t spike the same way. Studies have shown that GNG production doesn’t increase even with extra amino acids.

By now we have made a few things clear:

  • Gluconeogenesis is the process of making internal glucose from non-carb sources, including protein
  • Gluconeogenesis is necessary for survival
  • Gluconeogenesis makes ketosis possible
  • Eating too much protein won’t increase the rate of gluconeogenesis

But eating protein isn’t just safe, it’s necessary.

3 Reasons Why You Should Eat More Protein On Keto

Here’s why eating adequate amounts of protein is beneficial on the ketogenic diet:


Most people on keto will limit their protein to 30-40 grams, limit their carbs to 10-20 grams, then eat an excessive amount of fat. This is a common mistake.

If your goal is to lose fat, increased protein consumption is a great way to approach your ketogenic diet plan. Here’s why:

  • Protein is more satiating than fat
  • Protein is more nutrient dense
  • People tend to overeat when protein is low

Additionally, the most effective way to start losing weight on keto is to burn your stored body fat for energy, not the new dietary fat you’re eating. 

If you eat too much fat, your body will burn that new fat coming in and won’t get the chance to burn your stored fat reserves.

You can overcome weight loss plateaus by increasing protein and lowering your fat consumption.


Your body needs to use more energy (calories) to burn protein than to burn to fat.

For example, when you eat a 100-calorie serving of grass fed beef, your body can only store 75% of it as calories because it requires 25% of calories to burn it and use it as fuel. Conversely, when you consume fat, you are storing up to 98% of it as calories.

This means you’re storing almost all of the calories from fat, whereas you’ll store less from protein since you use up some of the calories to burn it.


Not eating enough protein on keto has serious side effects, including:

  • Worsened workout performance: Without enough protein, you won’t be able to maintain muscle mass, let alone build muscle.
  • Neuron atrophy: Your brain needs amino acids to function optimally. Research finds a protein-deficient diet can lead to atrophy and neuron loss.
  • Weaker immune system: A deficiency in the amino acid arginine can contribute to the dysfunction of your T cells — the cells that regulate your immunity.
  • Increased risk of diseases: A deficiency in amino acids can increase the risk of developing certain diseases, including: sickle cell disease, acute asthma, cystic fibrosis, pulmonary hypertension, cardiovascular disease and certain cancers.

In fact, a lot of these keto side effects happen due to eating too little protein:

  • Thyroid problems
  • Weight loss plateaus
  • Hormonal problems
  • Hair loss

Now that you know why protein matters, it’s important to choose the best possible protein sources for your diet.

Choosing the Best Keto Protein Sources

When selecting keto protein sources, choose the highest quality you can reasonably afford.

When grocery shopping, be sure to refer to the Keto Diet Food List and the Ketogenic Diet Grocery List for ideas. If you are an athlete who typically uses protein powder, choose a keto-friendly brand (discussed below).


These are the best sources of protein on the keto diet:

  • Beef, preferably fattier cuts like steak, veal, roast, ground beef and stews
  • Poultry, including chicken breasts, quail, duck, turkey and wild game — try to focus on the darker, fattier meats
  • Pork, including pork loin, tenderloin, chops, ham, bacon and ground
  • Fish, including mackerel, tuna, salmon, trout, halibut, cod, catfish and mahi-mahi
  • Shellfish, including oysters, clams, crab, mussels and lobster
  • Organ meats, including heart, liver, tongue, kidney and offal
  • Eggs, including deviled, fried, scrambled and boiled — use the whole egg
  • Lamb meat
  • Goat meat
  • Grass fed, full-fat dairy, including grass fed butter, heavy cream, cottage cheese and cream cheese
  • Vegetarian sources, like macadamia nuts, almonds and nut butter


Collagen is a type of protein — the most abundant protein found in your body.

It’s considered the glue that holds your body together, making up the tissue in cartilage, muscles, joints, skin, hair, eyes, heart, gut, brain, and nails, and it’s credited with a wide range of health benefits, including:

  • Better skin health
  • Hair loss prevention
  • Muscle growth and regeneration
  • Maintaining the integrity of tendons, ligaments and cartilage
  • Strengthening your bones and preventing osteoporosis
  • Repairing tissues (forming scars)
  • Maintaining proper vision
  • Preventing leaky gut
  • Helping your heart beat
  • Ensuring optimal brain function

How Much Protein Should You Consume on Keto?

The Standard American Diet (SAD) is heavy in carbs, with some protein and very little fat. On keto, you take a seemingly opposite approach, with the bulk of your calories coming from fat, some calories coming from protein and very few from carbohydrates.

While every person has individual needs, most people follow these macronutrient guidelines to enter (or stay in) ketosis:

  • 75-80% of calories should come from fat
  • 20% of calories should come from protein
  • 5% of calories should come from carbohydrates

This is a common way to break down your macros on the ketogenic diet. And while it may help you to start producing ketones, it may not be the most effective approach for overall body composition and weight loss.

Instead of setting up macronutrient percentages, here’s a better alternative:


The first step for successfully tracking your ketogenic diet macros is to calculate your protein intake.

The amount will differ depending on the activity level per individual.

If you’re sedentary, consume 0.8 grams of protein per pound of lean body mass at a minimum.

Lean body mass is the amount of weight you carry that isn’t fat. Use a bioelectrical impedance scale, calipers or get a DEXA scan to find your lean body mass. Then take that weight and multiply it by 0.8. This is the amount of protein you should eat every day.

If you’re an athlete or looking to build muscle, consume 1-1.2 grams of protein per pound of bodyweight.

Note: This is the absolute minimum you should be eating. You can eat more if needed and you shouldn’t worry about creating excess glucose. It’s more problematic to get less protein than it is to eat more.


Reduce your carbohydrate intake to 20-50 grams of total carbohydrates.

Athletes and those looking to build muscle can consume higher amounts whereas people who live a sedentary lifestyle should try to stay under 30 grams of total carbohydrates.


Once you have calculated your protein and carbohydrate intake, subtract that amount from your daily total calories.

Those remaining calories should come from healthy fats.

To find the amount of calories per macronutrient:

  • Protein = 4 calories per gram
  • Carbohydrates = 4 calories per gram
  • Fats = 9 calories per gram

Here’s an example:

Let’s assume your goal is to eat 150 grams of protein per day and 30 grams of carbohydrates with a 2,100 daily calorie allowance.

  • 150g protein x 4 = 600 calories
  • 30g carbohydrates x 4 = 120 calories
  • 2,100 – (600 + 120) = 1,280 calories
  • To find your fat intake = 1,280 / 9 = 142g of fat

The macronutrient breakdown for this example comes out to:

  • 150 grams protein
  • 142 grams fat
  • 30 grams carbohydrates

If you’re not seeing the results you want with the ketogenic diet, using this approach may help you overcome any ketogenic obstacles you’re experiencing.

What to Measure: Results Not Ketones

If your goal is to maintain optimal energy levels and achieve a lean physique, you should not worry about constantly tracking your ketone levels.

Instead, focus on long-term lean tissue growth.

Ketone production is not the only metric to track when gauging your success on the ketogenic diet.

Looking at the mirror, measuring your lean body mass and assessing your energy levels are much better ways to determine the effectiveness of your diet. Why?

Because producing ketones doesn’t always mean you’re burning themfor energy.

When you first start the ketogenic diet, your body may be excreting excess ketones through your breath and urine. Often times, these ketones aren’t being used for energy because your mitochondria haven’t adapted to processing ketones effectively.

The longer you follow the ketogenic diet, the more efficient your body becomes at using ketones as its main fuel source.

This is why many people who are keto-adapted will have slightly lower ketone levels (.6 – .8 mmol). Their body isn’t flushing out excess ketones — it’s using them.

Building lean mass overtime is a better indicator of an effective ketogenic diet protocol because it proves that you’re burning off your body’s fat storages for energy.Bottom Line: Unless you are following the ketogenic diet to help with serious health conditions like cancer or Alzheimer’s disease, maintaining high ketone levels should not be a priority for you. Instead, track your overall body composition, lean tissue growth and energy levels.

Stop Undereating Protein

Many people in the ketogenic community have been misguided into keeping protein intake relatively low to prevent glucose production through GNG.

Because of this, keto beginners may never see the lasting results they’ve been promised on the low carb, high fat lifestyle.

The truth is protein is just as important as healthy fats on the ketogenic diet. 

If you have hit a weight loss plateau, experienced a dip in energy or noticed hormonal imbalances, increasing your protein intake can drastically help.

Instead of focusing on ketogenic macronutrient percentages, follow the steps above or use the macro calculator to figure out your new macro intake and make your keto diet work even better for you.

Source: Article by Dr. Anthony Gustin (

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