How Much Protein Do You Need to Get Into Nutritional Ketosis?

Large Wok Filled with Pork Ribs and Veggies
How much protein can you eat
and still get into Nutritional Ketosis?

Nutritional Ketosis (LCHF) is totally misunderstood by the low-carb community -- especially in terms of dietary protein. Nutritional Ketosis (LCHF) is a low-carb, high-fat diet that became popular within the low-carb community in 2012.

This post cuts through the myths and helps you set your protein intake to what Dr. Phinney intended.

Nutritional Ketosis was originally created for endurance athletes. This LCHF diet recommends that you monitor your blood ketone level by purchasing a special ketone meter to measure the amount of ketones built up in your bloodstream.

These ketone strips are not the test strips that measure acetoacetate ketones in your urine. Instead, they measure beta-hydroxybuterate that the body converts from acetoacetate to fuel the brain.

Due to using these blood-ketone strips, many low carbers discovered that they were not in the optimal Nutritional Ketosis zone, as defined by Dr. Phinney, even though they had been drastically restricting carbohydrates.

This discovery sent ripples of shock through the low-carb community, and resulted in many individuals taking their protein levels down to dangerous depths to achieve these athletic levels of ketones.

In this post, I'm going to reveal the truth about protein consumption as taught by Dr. Phinney and explain how much you need to stay healthy and fit.

What is Optimal Ketosis?

Nutritional Ketosis for the average dieter recommends that you keep your blood ketones within an optimal range of 1 to 2 mmol/L, but any level between 0.5 and 3 mmol/L is fine.

The higher end of the range is typically reserved for endurance athletes.

Several Bike Racers on a Ride
Optimal Ketosis is 1 to 2 mmol/L.
Endurance athletes can go as high as 3.0 mmol/L.

These blood-ketone sticks are not cheap, but they enable you to get a clearer understanding of what's going on.

For that reason, many of the misconceptions held about glucose, protein, and gluconeogensis were re-evaluated and new conclusions and theories arrived at due to additional self-testing.

Through trial-and-error, many dieters came to realize that the only way to get into optimal ketone range, and stay there, was to limit their protein. However, a blood ketone monitor is not the only way to optimize your LCHF diet.

If you carefully follow Dr. Phinney's recommendations, and adjust them to fit your particular situation, you can easily hit your personal protein target and reap the benefits.

But how much protein do you need to get into Nutritional Ketosis?

Do You Really Have to Limit Your Protein to Get into Nutritional Ketosis?

Unlike the older Atkins diets that had no limit on dietary protein and used carbohydrate restriction as their total focus, Nutritional Ketosis requires you to limit the amount of protein you eat. 

However, you still have to eat the amount of protein it takes to meet your body's protein needs. 

Slashing your protein consumption to the bone is NOT Nutritional Ketosis.

Nutritional Ketosis is a rough guide you can use to make sure you are eating ENOUGH protein.

It is not the other way around.

Limits imposed have to do with excess amino acids over-and-above your protein and carbohydrate needs.

Many people have bought into the out-dated notion that low carb means you can eat all the steak and chicken you want and still lose weight, provided your carbs are kept low. That belief simply isn't true.

Overeating protein calories can interfere with your weight-loss goals, the same as overeating carbohydrates can.

Where Did the Idea to Cut Protein Consumption Come From?

Carbohydrate restriction triggers ketosis, but many people with insulin resistance over-secrete insulin in response to meals and snacks.

Carbohydrates carry the biggest insulin wallop, but protein foods like meat and cheese also raise insulin levels significantly. Insulin helps the amino acids get from the cheese and meat you eat into your body's cells more quickly.

An insulin spike is NOT BAD!

What's detrimental to the body is when insulin stays elevated for several hours at a time.

In 2012, after The Art and Science of Low-Carb Performance came out, Jimmy Moore, an influential blogger, decided to run a n=1 experiment on himself and fiddle with his dietary macronutrients to see what it took to bring his blood ketone level into the optimal zone for endurance athletes.

Man Playing Basketball
The idea about cutting protein came from
an n=1 blogger experiment and NOT Dr. Phinney

Using the maintenance formula presented in that book for optimal performance:
  • 15 percent protein
  • 5 percent carbohydrate
  • 80 percent fat
Jimmy experienced wonderful results!

Encouraged by Jimmy's success, many of his readers followed in his footsteps. They purchased blood ketone meters, saw that they were not in optimal ketosis, lowered their protein consumption, upped their fat, and voila!

They were magically in the state of Nutritional Ketosis!

Human nature tends to perceive the world in terms of extremes, so what started out as a recommendation to limit your protein calories to 15 to 20 percent of your total maintenance needs, suddenly got blown way out of proportion.

Since carbs were already being restricted and fat doesn't affect insulin levels significantly, most low carbers began to falsely believe that the only macro left to get you into the optimal zone for Nutritional Ketosis was protein.

But this was a serious misconception.

The Truth About Gluconeogenesis

Gluconeogenesis is demand driven. It is a back-up system designed to keep the brain alive, which means the liver won't break down glycogen into glucose unless the body really needs it.

If you go too low in carbs, elevated cortisol and glucagon encourage the liver to break down glycogen into glucose, regardless of how much glucose you already have running around in your bloodstream.

The same thing happens when you're under a great deal of stress. Cortisol goes up and glycogen gets broken down into glucose, which is then dumped into the bloodstream.

To the liver, the presence of cortisol and glucagon means your blood sugar is too low, so the liver responds to that information as if it were true.

How the Low-Carb Community Responded

As a result of the false belief that too much protein can kick you out of ketosis, people started taking their protein consumption down to dangerously low levels. They also tried to get the amount of ketones in their blood up as high as possible.

Oddly enough, the higher these people went in ketones, the slower the body fat came off, with many reports revealing that people were gaining weight eating this way -- including me.

Once you have adapted to ketosis, ketones are mostly used to fuel the brain. They are not used to fuel your daily activities, unless you're an endurance athlete. The buildup of ketones in the blood higher than 2 or 3 mmol/L won't benefit fat loss.

Body fat isn't going to suddenly melt away if you eat more fat than you need.

In fact, a ketone level over 3 mmol/L is a sign that you have gone into STARVATION (protein deficiency), especially if you are not an endurance athlete. Protein deficiency causes all sorts of nasty things to happen to you, including water retention.

As a result of these misconceptions about protein and weight loss, many women were only eating 40 to 50 grams of protein a day, terrified of eating too much and having the excess turned into glucose. It was a fast-and-easy way to blame weight-loss challenges on protein.

With so many people stalled partway to goal, the distorted LCHF diet became popular almost overnight.

What Really Happens to Excess Protein?

Pork Chops Simmering in a Low-Carb Mushroom Gravy
What really happens
if you eat too much protein?
As protein is broken down into amino acids in the gut, the amino acids enter the bloodstream.

Branched chain amino acids are absorbed by the muscles and the rest of the amino acids end up at the liver for processing.

At the liver, some amino acids are turned into glycogen and stored, but they can also be directly burned to fuel triglyceride breakdown in the liver. Amino acids are used for tissue repair, enzymes, antibodies, and a lot of other things.

Branched chain amino acids absorbed by the muscles trigger protein synthesis, so muscle is in a constant flux. Proteins are broken down and rebuilt on a continuous basis, the same as all other protein structures in the body.

If there are excess branched chain amino acids, over and above what the body needs for muscle repair, these amino acids enter the pathway of energy production.

Through a series of steps, the extra amino acids are converted in the muscle to pyruvate, and then into alanine, so it can be shipped to the liver.

In the liver, alanine is converted back into pyruvate. The pyruvate is then converted into glycogen, so it can be stored and used to help keep your blood glucose level steady, as well as supply the glucose the brain needs.

All of this converting and re-converting is a lengthy process.

Glycogen will be converted to glucose, as needed, which is where the idea that protein can be turned into sugar actually comes from.

What most people don't understand, however, is that on a LCHF diet, stored glycogen is only used for a few particular purposes:
  • fuel the brain, kidney, and red blood cells
  • keep blood glucose level from dropping too low
  • fuel sudden emergencies that require you to fight or run (which includes intense athletic activities) 
If you are fat-adapted, your muscles will be burning fatty-acids for fuel. By this point, they are insulin resistant, so they won't absorb the glucose in the blood. Glucose in the blood is saved for the brain and other things, so the fear of protein makes absolutely NO SENSE! 

The fact that the muscles don't use glucose on low carb, except under intense conditions is an important point because many low carbers are terrified of glucose, insulin, and even carbs.

The whole point of Dr. Phinney putting well-trained athletes into the state of ketosis is so their muscles will run on FAT!

Brain Requirements

The brain can derive up to 75 percent of its energy needs from ketones, a waxy substance that results when triglyceride is broken down into fatty acids. Once you have adapted to the state of ketosis, the brain only needs about 35 to 45 total carbs a day to fill its needs.

If you don't eat those 35 to 45 carbs, like most low carbers do not, you'll need to eat a bit more protein, so the liver has the extra glycogen it needs to take up the slack.

How much protein you actually need to eat on a daily basis depends on how many carbohydrates you're regularly eating. The more carbs you eat, the less protein you need. The fewer carbs you eat, the more protein you need. 

This is why Phase 1 of Nutritional Ketosis begins with 5 percent carbohydrate instead of 20 grams. At 35 to 45 carbs, you're able to keep your protein intake lower than you could if you were only eating 20 carbs per day, or less.

Nutritional Ketosis Protein Requirements - What is Adequate Protein?

Dr. Phinney recommends you limit your protein to about 15 - 20 percent of the calories you will need to eat at maintenance to manage your weight.

This predictive number is because your protein needs won't change very much as you travel through the four phases of Nutritional Ketosis.

If you are severely obese, then yes, you'll lose a bit of muscle mass as your weight normalizes. Your protein needs might go down slightly from what they were when you started.

For the average dieter, the amount of protein you need on day one of your LCHF diet is the same amount of protein you'll need to maintain your losses.

For example, if I weighed 125 pounds today, my calorie needs would be about 1500 calories, or so. I have a large skeletal frame, so one-fifth of those maintenance calories (20 percent) would be 300 calories. Since protein has 4 calories per gram, I would divide those 300 calories by 4 to arrive at 75 grams of protein.

Dr. Phinney's recommendation is right on. This was the exact amount of protein I ate in 2007 when I was having the best weight-loss results.

Protein Intake Needs to be Individualized

The above recommendation is simply a rough guide. It's not an absolute requirement.

If you're extremely active, Dr. Phinney recommends you start out eating at a higher amount, about 25 percent of your calories in protein, rather than 15 - 20 percent because your protein needs will be higher.

Most people who are overweight tend to have sit-down jobs.

If you sit for most of the day, you won't need as much protein as someone who has a job that requires several hours of physical labor every single day.

Use these figures as a starting point only.

Your personalized daily requirement for protein might be more or less. Plus, protein requirements can change, depending on your age and current health status or situation.

If your bone structure is small, rather than large like mine, 15 percent of your calories in protein will probably be plenty. If you are injured, you'll need extra protein over-and-above the 20 or 25 percent to help the body heal faster.

As you get nearer to goal weight, meeting your protein needs during dieting and getting in enough dietary fats will become more essential because there won't be as much body fat to draw upon.

While getting to goal can be an exciting time, you still need to use some common sense.

Want Pictures of Serving Sizes for Protein?

If you're having trouble getting your low-carb high-fat diet to work well, check out our article on protein and starvation for tips and advice from Dr. Phinney. This article includes a lengthy list of protein serving sizes, along with photos, to help make sure that you're eating enough.


  1. Wow! I'm so happy I found your blog! My weight loss problems are very similar to yours. I'm 5'1" and weigh 172. 55 years old. I've done every diet under the sun, and always end up back in the 170-180 range. Kimkins was my most successful diet, but I gained it all back when I added back the carbs.

    I've recently come to the conclusion that there is no magic diet. I'm a small person, and I need fewer calories than everyone else. I also know I have gluten sensitivity. Possibly celiac. I have a sister who had a positive diagnosis, and we share some of the same symptoms. Your posts have inspired me to give this another go with lower calories and no gluten/starch. I don't really want to lose that much weight. About 140-145 is what I'm shooting for.

    Sorry for writing a book. I really just wanted to say Thank You for motivating me again, and to let you know that you've got a new fan reading your blog!

    -- Maggie

  2. Long comments are great! I've recently come to the same conclusion as you. I'm going to raise my goal weight to something I can comfortably maintain. Hope to hear from you again!

  3. This is interesting - do you have a citation for the values of what looks like .6 grams of protein per lb of lean mass? I've come across a lot of conflicting information in regard to determining appropriate protein levels.

    Thanks for writing!


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