What if everything you thought you knew about keto protein consumption was wrong?
What if the secret to weight loss on a keto diet isn’t fat, but protein?
While it’s easy to see why healthy fats are the stars of a ketogenic diet, many keto experts recommend way too little protein to support lean mass and recovery.
Your body uses protein for more than just muscle building. Read on to find out how you can lose more weight, improve body composition, and keep your blood sugar balanced — all while increasing your keto protein intake.
There are over 10,000 different proteins in your body — from your bones, muscles, and connective tissues to your hair, skin, nails, and the lining of your GI tract and blood vessels[*].
When your body digests protein, it’s broken down into molecules called amino acids, some of which are essential amino acids your body needs and cannot produce on its own.
People often call amino acids “the building blocks of life” since they’re involved in[*]:
- Building muscle
- Maintaining the structure of your muscles, tissues, and organs
- Making enzymes
- Creating hormones
- Building neurotransmitters
- Metabolizing your food and transporting nutrients
- Producing antibodies to strengthen your immune system
- Carrying oxygen in your blood via hemoglobin
Your body can’t store protein in the same way it stores carbs and fat, so you need to make sure you’re eating the right amount of protein every day.
But protein also has a few more roles to play:
- Protein helps you feel full: Protein is nutrient-dense, satiating, and takes time to digest. This helps when you’re trying to curb hunger and lose weight without starving yourself[*].
- Protein builds muscle, which burns calories: It keeps burning calories even when you’re not working out. It will be easier for you to create a calorie deficit and lose stubborn fat with more muscle mass on your side[*].
- Protein is essential for recovery after your workouts: This is because every time you tear your muscles when working out, you need protein to build them back up bigger and stronger[*].
Plus, when you start building muscle and shedding fat, you may not lose weight, but your body composition will improve. You’ll begin to look toned instead of flabby the more you work out and refuel with protein.
Yes, gluconeogenesis is a metabolic mechanism where your liver and kidneys make glucose from non-carbohydrate sources like protein.
But you don’t have to worry about protein kicking you out of ketosis.
Your body needs to maintain a certain blood sugar level at all times, whether you’re in ketosis or not.
However, your body is capable of making the small amount of glucose it needs to function without you eating 15 cookies to give it that sugar.
When you cut carbs and sugar from your diet via a ketogenic diet or intermittent fasting, your body panics and looks for glucose — it will deplete your glycogen (glucose) stores because they’re the most accessible backup source.
Your body (specifically, your liver) can then turn to other non-glucose energy sources to create the glucose it wants since you’re not providing it via your diet.
That process is called gluconeogenesis, and it’s not as intimidating as it sounds.
Gluconeogenesis (GNG) means creating new glucose.
Why does gluconeogenesis exist?
Your body needs some amount of glucose to function. So, even though you’re intentionally limiting carbs on a keto diet, your body’s first instinct is to protect you from glucose starvation.
Think of gluconeogenesis as your body’s backup source of glucose. And it happens when your body forms glucose from protein when it doesn’t have enough carbs[*].
The common worry among keto dieters is that if you cut carbs and eat too much protein, you may run the risk of that protein turning to sugar and raising your blood sugar levels.
Theoretically, you could even raise your blood glucose enough to kick you out of ketosis.
Or could you?
What the Science Says About GNG
Studies show that digesting protein stimulates the production of glucagon, a hormone that helps break down glycogen to glucose in your liver. This means protein should increase the chances of GNG happening when you’re on a low-carb diet[*].
However, your body also sends out insulin to handle all that glucose, so it nets out and doesn’t matter to the average person[*]. There’s also some evidence that gluconeogenesis liberates glucose so slowly, it would be tough to experience high blood sugar after just one high-protein meal[*].
Unless you’re an insulin-dependent diabetic or struggle with insulin resistance or insulin sensitivity issues, protein shouldn’t affect your blood sugar levels.
To test the theory that half of dietary protein becomes glucose, scientists in one trial gave participants 160 grams of protein (that’s a lot) and expected to see 80 grams of glucose produced in return[*].
They measured blood sugar levels after the participants ate lean beef, egg whites, and casein, but the effect on blood glucose (BG) levels was still the same: nil.
Researchers in this study wanted to know how protein intake contributed to the body’s glucose production[*].
So, they had participants fast overnight and then eat a protein-rich meal without carbs the following day. The scientists laced the protein source, which in this case was eggs, with a tracking substance so they could watch it throughout the digestion process.
Even after an overnight fast and a meal without carbs — which are ideal situations for GNG to happen — blood sugar levels remained relatively stable as you can see in this chart:
The black dots represent the participants’ normal blood sugar levels during the eight hours after they ate. The open white circles show the effect of the tracked protein source (i.e., the special eggs) on the participants’ blood sugar levels during that same window of time.
This graph reveals that dietary protein contributed very little to overall glucose production — even when they created ideal conditions for gluconeogenesis to occur.
Further, over eight hours after protein intake, scientists noticed:
- Participants’ livers produced around 50 grams of glucose (presumably from digesting that protein)
- Just 4 grams of glucose creation came from the laced protein or about 8%
- The protein was not enough to elevate blood sugar levels
This study used two parts: an overnight fast and a protein-rich meal.
So how does fasting alone contribute to GNG?
Fast overnight and studies say half of all glucose released into your bloodstream is the result of GNG[*].
Yet five participants following a keto diet for 11 days only noticed a small increase in glucose production from GNG after overnight fasting. This 14% increase was equal to a rise in blood sugar of less than 1 gram of glucose per hour[*].
The Truth About Gluconeogenesis and the Keto Diet
In the same way, you can’t gorge on fat and claim to be in ketosis; you don’t just splurge on protein and find yourself kicked out of ketosis because of GNG.
Gluconeogenesis is a slow and steady process with a fixed rate.
A rise in blood sugar after you eat a protein-rich meal doesn’t automatically signal GNG as it generally takes longer for your body to liberate glucose from protein.
Any rise in your blood glucose levels is most likely due to your liver releasing hormones to digest that protein.
One of the most important facts to remember is that GNG doesn’t happen because it can; GNG only happens when it needs to.
Studies show that having more protein in your diet doesn’t increase the rate at which GNG occurs[*].
If GNG were a supply-driven process, an excess of protein would trigger the start of it.
But just because your body has too many amino acids doesn’t mean they’ll get converted to glucose.
If your body doesn’t need this glucose, your body won’t search for it or create it from something else.
Gluconeogenesis can also happen with fat — not just protein.
Studies show over 90% of all GNG happens with[*]:
- Lactate and glycerol, which your body breaks down from triglycerides (stored fat) and glycogen (stored carbs) when there’s not enough dietary glucose.
- Glutamine and alanine, two amino acids found in proteins throughout your body that are preferred sources for GNG when carbs are low. Your kidneys like glutamine, but your liver goes for alanine[*].
In reality, the process of GNG is incredibly rare when you’re speaking about healthy bodies under normal conditions.
When GNG Is Most Likely to Happen on Keto
A ketogenic diet trains your body to use fat for energy instead of glucose.
But it can take your body up to three weeks to reach ketosis.
It’s during this transition — before you get into ketosis — that your body is more likely to turn amino acids into glucose.
It generally takes between 18-72 hours for your body to use up all its glycogen stores. When there’s none left, free-floating amino acids will be your body’s go-to fuel source.
At this point, your body is used to running off of glucose and isn’t very efficient at burning ketones. Because of this, your body may turn to protein and fat for glucose a little more than when you’re entirely fat-adapted.
So, the first three weeks of your keto journey are when you’re the most vulnerable for GNG.
Eventually, your body will figure out that protein and amino acids aren’t an ideal long-term fuel source via GNG, and that ketones are a way more efficient energy source.
Again, just because protein can turn into glucose doesn’t mean it will. When your body needs glucose, it will make whatever small amount it needs.
But eating an adequate amount of protein is the key to reaching ketosis for this to happen.
If you don’t eat enough, your body could start converting your muscle mass protein to glucose, which can cause significant damage.
You might experience some gluconeogenesis when you’re just starting on a keto diet. But it will happen on a much lesser (and as-needed) scale once you’re fat-adapted.
It’s much more likely that you’re not eating enough protein on a ketogenic diet. And this common mistake could sabotage your energy and weight-loss goals.
You may not even realize you’re eating too little protein. That’s because when you’re switching to keto, you’re eating more satiating fat, and your cravings are diminishing.
As such, it’s essential to calculate your ideal protein intake and make sure you’re getting enough of it to support your goals and activity level.
Signs You’re Not Eating Enough Protein
- You feel weak and tired all the time.
- You’re plagued by brain fog despite adding MCT oil to your keto coffee.
- You have thinning hair, peeling skin, and weak, brittle nails.
- You feel hungry all the time and constantly crave sweets.
- You gain weight or are unable to lose weight because you have more body fat than fat-burning muscle.
- You’re often sick since you have less protein-producing antibodies to protect you.
- Your legs, ankles, and feet are swollen, caused by fluid buildup in your tissues, which your blood vessels should transport with protein’s help.
- You’re losing muscle mass, which also slows your metabolism, so you burn fewer calories at rest.
If you’re losing weight and better cognitive performance and more physical energy on keto, your protein intake may be correct.
If you’ve been following macros that start with fat instead of protein — or rely on general percentages instead of your body’s specific needs — that’s the first change you’ll want to make.
Many keto diet macronutrient calculators rely on the traditional breakdown by percentage:
- 70-80% of your calories come from fat
- 20-25% of calories come from protein
- 5-10% of your calories from carbs
These percentages are for a therapeutic keto diet designed for epileptic patients. It might work for some people, but most healthy adults need more protein.
If you want to lose weight and build or maintain muscle, you need to prioritize your protein levels first.
Start with how many grams of protein your body needs to perform its daily functions. You can figure that out with this free keto calculator.
After you figure out your ideal protein intake, then it’s time to determine your carbs. The typical range is 25-50 grams of carbs per day in keto, depending on your unique needs.
The final piece of the puzzle should be fat.
You’ll need to figure out how much fat you’re allowed to eat on keto to reach your goals (i.e., weight loss versus maintenance).
When you can’t have too many carbs, many people think eating more dietary fat is the answer.
But if you’re not losing weight immediately, you may be eating too much fat.
When you load up on dietary fat, your body will prioritize burning that — not your fat stores, i.e., body fat.
If weight loss is your goal and you have a substantial amount of body fat, you don’t need to add tons of dietary fat to the menu.
Protein is a dieter’s secret weapon since it helps you eat fewer calories and builds more fat- and calorie-burning muscle.
How to Calculate Your Ideal Daily Protein Intake
Protein intake isn’t a one-size-fits-all number.
Your protein needs depend on your:
- Activity level
- Body composition (i.e., lean body mass, or your total weight minus your body fat)
There are two ways to find your ideal protein intake range.
#1: Use the Perfect Keto Macro Calculator
If all that math seems like a pain, you can always plug in your numbers to the Perfect Keto Macro Calculator. You’ll have your protein macro in less than a minute.
You’ll also score your recommended carb intake and daily calorie goals.
Keep recalculating your macros and adjusting them as you lose weight, gain muscle, and get further into ketosis and fat adaptation.
If building more muscle is your goal, then you should consume keto-friendly protein foods.
#2: Do the Math Yourself
To use this method, you’ll need to determine your body fat percentage first.
You can estimate your body fat percentage based on pictures or calculate it based on your body weight using this formula.
Once you have your body fat percentage, it’s time to determine your lean body mass (LBM).
Take your total weight minus your body fat to get your lean body mass.
For example, if you weigh 200 pounds, and you have 30% body fat, your LBM is around 140 pounds.
To fill out the rest of the equation, use a multiplying factor based on your lifestyle:
- 0.6 for sedentary activity levels (the minimum protein intake in general)
- 0.7 for lightly active levels
- 0.8 for moderately active levels
- 0.9 for very active lifestyles
- 1.0 for extremely active people (the maximum average protein intake)
If you’re not sure where you fit, you can always determine your ideal protein intake range to experiment.
Using that example, take your LBM (140 pounds) and multiply it by 0.6 to get your minimum protein amount (140 x 0.6 = 84 grams).
Do the same for your maximum protein intake (140 x 1.0 = 140 grams).
The ideal intake range, in this case, would be between 84-140 grams of protein per day.
Split up this amount throughout your day between keto meals and snacks to make sure you’re getting a steady supply instead of protein loading all at once.
Remember to stick to the high end of your protein intake range during your most strenuous days and the low end for less active ones.
Follow a High-Protein, Low-Carb Diet
You don’t need carbs to build muscle, but you may need more muscle-building protein than what a standard ketogenic diet offers.
In this case, you may want to try a high-protein ketogenic diet, which some daily lifters swear by.
A high-protein ketogenic diet looks more like:
- 60% of calories from fat
- 35% of calories from protein
- 5% of calories from carbs
Since it’s important to use accurate numbers to find your protein intake first, bodybuilders may be able to up their multiplying factor to between 1.2 and 2.0 when they’re in ketosis.
Going back to the previous example, that 200-pound person with 140 pounds of LBM can eat between 168-280 grams of protein each day if they’re working out a lot and want to pack on more muscle mass.
Even though you shouldn’t be scared of GNG, you also shouldn’t eat more protein than your body needs either.
Signs You’re Eating Too Much Protein
Studies show there’s no benefit to gorging on loads of protein if your body doesn’t need it. It can cause adverse side effects such as[*]:
- Indigestion, constipation, or diarrhea
- Kidney damage
- Fat gain
- Possibly lower ketone levels — since your body uses excess protein for energy, it may not produce as many ketones as it will need to use up that protein first
Protein Intake and Ketone Levels
You may find that your blood ketone levels go down when you eat a lot of protein, but that doesn’t mean you’re not in ketosis or that you’re not losing weight.
Don’t undereat protein just to keep your ketone levels in the “optimal” range.
Ketones don’t cause fat loss; they indicate your body’s actively breaking down your fatty acids and may be on its way to ketosis (or already there).
You can have high ketone levels and still not lose an inch of body fat or gain an ounce of lean muscle.
The best way to see how your body responds to protein is to act like a scientist and observe yourself.
Watch, Track, and Learn
First, use the macro calculator above or do the math to find your ideal protein range.
Then, track your food intake and watch your ketone levels after eating different serving sizes of protein. Also, keep a note of your energy and performance levels when working out.
Gluconeogenesis might be a problem if you’re pounding protein shakes, eating steaks for every meal, and skipping the gym.
But for the average keto dieters who only go over their protein macro by 5-15 grams, GNG is nothing to worry about after the adaptation phase.
A typical serving of protein will be between 4-6 ounces for women and 8 ounces for men.
It’s mission-critical to choose high-quality keto protein sources found in natural and whole foods, such as:
- Fatty cuts of organic, grass-fed meat, including beef, bison, lamb, pork, and poultry
- Fatty, wild-caught, sustainable seafood like tuna, salmon, halibut, cod, mahi, catfish, sardines, anchovies, shrimp, and lobster
- Eggs, nuts, seeds, and high-fat, low-carb dairy
- Organ meat such as heart, liver, tongue, and kidney
- Supplements like collagen protein, whey protein isolate, and other keto protein supplements
Watch out for certain processed meats, high-sugar protein bars, and questionable protein powder sources. Many of these contain artificial ingredients, added sugars, and other hidden carbs.
Why You Should Focus on Protein, Not Fat
Anyone on a ketogenic diet knows the health benefits of good fats.
But it’s time to recognize protein for the powerful macro it is. If you’re into keto for fat-burning and muscle maintenance, you might want to rethink how much protein you’re eating.
It’s not accurate to think that gluconeogenesis is the result of an excess of protein when you’re eating keto.
There’s no evidence to suggest that protein on keto immediately turns to glucose. Yet, there’s ample literature on how beneficial protein is for curbing appetite and improving lean muscle mass.
Determine your ideal protein intake using math or the Perfect Keto calculator, then add a few protein-rich keto recipes to your keto menu planning to make sure you’re meeting your daily intake amount.
Sneak in 30 minutes of exercise on top of this, and you’ll be one giant step closer to reaching ketosis and getting all the benefits of a keto lifestyle.