How to Build Muscle on Keto: The Ultimate Guide

The ketogenic diet is an increasingly popular low-carb, high-fat diet. When you’re doing keto, you pretty much eliminate carbohydrates from your diet and replace them with fat. 

You probably know the ketogenic diet as a weight-loss method. As such, it’s popular and successful, mainly because it makes you feel full and eat less.

However, many people think that it is difficult or even impossible to build muscle on keto. That’s because your body prefers carbohydrates when you lift weights and because carbs release insulin, an anabolic hormone.

Recent research shows that even high-level powerlifters make strength gains on a ketogenic diet, but gaining muscle might be a bit more tricky without carbs.

In this article, you’ll find everything you need to know about building muscle on keto.

What Is Keto?

The ketogenic diet is both a low-carb diet and a high-fat diet. You decrease your carb intake to 5–10% of your energy intake and replace those calories with fat.1 If you eat 2,000 calories per day, that means staying below 50 grams of carbs per day. Some people go for an entirely carbohydrate-free approach.

After some time without carbohydrates, your body enters a state called ketosis. It usually happens after a couple of days, but it can take a week or longer for some people.2

When you’re in ketosis, you switch from carbs to alternative fuel sources, namely fat and ketone bodies. When you run out of carbs, you release large amounts of fatty acids from your body fat, and your liver makes ketone bodies from them. Ketone bodies then replace carbs as your primary energy source.

You stay in ketosis as long as you don’t eat any carbs. Your body uses ketone bodies to fuel your muscles, organs, and even your brain, which is usually a sucker for sugar.

A ketogenic diet is at least as effective for weight loss as a low-fat diet. It also improves blood lipids and blood sugar in overweight and obese persons.3 4

Can You Build Muscle on Keto?

Yes, you can. There are numerous real-world examples of people transforming their physiques and gaining muscle while on a keto diet.

Research also shows that it is possible to gain muscle tissue and lose fat simultaneously with keto. For example, in a 2020 study, 25 young men participated in a strength-training program while following either a ketogenic diet or a traditional Western diet for 12 weeks.5 Both groups increased their lean body mass. In addition, the keto group experienced more fat loss.

Other studies are not as optimistic. One review concluded that keto might help you maintain your hard-earned lean muscle mass on a weight-loss diet but make muscle hypertrophy more difficult.6 7 8 Most of them show that you perform just as well in the gym on keto, but that you might find it harder to gain muscle without carbs.

Difficult or not, you can gain muscle on keto. Also, I suspect other dietary factors than the lack of carbohydrates might be why some studies find that keto isn’t optimal for muscle growth. You see, they don’t control the diet of the participants. Keto is well-known for increasing satiety and suppressing appetite, which might very well have caused them to eat less than they needed for muscle growth. The keto groups often lose fat, while the non-keto groups don’t, supporting my theory.

A recent meta-analysis also supports my suspicions and finds that the ketogenic diet is a good alternative for building muscle as long as you’re able to eat enough calories.9 Preferably, you’re able to maintain a caloric surplus over time. Because keto makes you feel full more than other diets, eating enough food is probably the most significant challenge. Ketosis in itself doesn’t seem to be the problem.

How to Build Muscle on Keto

The three most important things to keep in mind when building muscle on keto are the same ones as with any diet:

  • Lift weights regularly. Nothing stimulates muscle growth like weight training.
  • Consume enough calories. If you eat too few calories, you’ll find it harder to build muscle.
  • Eat plenty of protein. A high-protein diet makes it much easier to gain lean muscle.

Let’s break it down, starting with diet.

How Many Calories Do You Need?

To gain muscle, you need to eat enough food. That means eating at least as many calories as you burn. While it is possible to build muscle and lose fat simultaneously, it’s much trickier.10 Even a moderate calorie deficit reduces your muscle protein synthesis after a week or so.11

Your first course of action is determining the calorie intake you need to keep your body weight stable. Our calorie calculator gives you an estimation of how many calories you need, based on one of the most widely used and accurate equations.

Calorie Calculator: Resting Metabolic Rate and Daily Need

Such equations aren’t 100% exact, but they give you a good starting point.

Alternatively, you can go the manual route. Record everything you eat and drink in your favorite food tracker for a week. If your weight is stable, you’ve found the number of calories you need daily.

Building muscle on maintenance calories is fine, but consider a slight caloric surplus if you want the best conditions for gaining muscle. Somewhere between 350 and 450 calories above maintenance is enough.12 You’re trying to gain lean muscle, after all, not body fat, so keep it moderate.

If you don’t track your calories, you might not be eating enough. That’s a more significant issue on keto than on a high-carb diet. You see, keto increases satiety.13 That’s great if you want to lose weight. But if you eat according to hunger, the ketogenic diet might actually prevent you from gaining muscle by making you eat too little. Be sure to check that you’re not undereating because of a blunted appetite.

Eat Enough Protein!

Protein and the essential amino acids are the building blocks of your body. When it comes to building muscle, protein is the nutrient to track. If you don’t eat enough protein, you’ll find it much harder to pack on muscle.

Studies show that you need a higher protein intake when training to gain muscle. Eating 1.4–2 grams of protein per kilogram of body weight per day is sufficient for most people.14 15 To be on the safe side, why not go for 2 grams per kilogram of body weight per day? It does no harm, and you ensure that your muscles have all the building blocks they need.

A common concern when on the ketogenic diet is that eating too much protein will kick you out of ketosis. 

Eating protein makes your body release insulin, just like when you eat carbs.16 Also, some of the protein you consume is converted to glucose, more so when you’re on a low-carb diet.17 That process is called gluconeogenesis

Protein doesn’t have much of an effect on your blood sugar.18

That means you can eat a lot of protein without worrying about your blood sugar spiking and bringing you out of ketosis.

The small amount of glucose your body gets from the protein you eat is useful, even on a ketogenic diet.

  • When you’re not getting any carbs from your diet, or if you fast, you maintain your blood sugar levels through gluconeogenesis.
  • Fatty acids and ketone bodies are your primary fuels when you’re on keto, but not all organs can do without carbs completely. Your testes (if you’re male), parts of your kidneys, and your red blood cells all require a steady flow of glucose into the bloodstream. From where does that glucose come? Gluconeogenesis.

In summary, a standard ketogenic diet isn’t very high in protein. However, when you engage in strength training, you need more protein than average if you want good results. A protein intake between 1.4 and 2 grams per kilogram of body weight per day is an excellent target.

Fortunately, you are unlikely to get kicked out of ketosis on a high-protein diet. You still need some carbs even when you’re on keto, but you don’t have to get them from pasta and pancakes. Instead, your body creates the glucose it needs from protein, allowing you to remain in ketosis and run on fat and ketone bodies.

Cut the Carbs!

Standard guidelines for carbohydrate intake for athletes recommend 5 to 7 g/kg/day.19 Those recommendations go out the window when you’re doing keto. Instead, you have to cut most, if not all, carbs from your diet if you want to reach and stay in ketosis.

How many carbs you can eat and still be in ketosis vary from person to person. Most people need to eat less than 50 grams per day, although some might need to go even lower.20

The best way to determine how low your carbohydrate intake has to be to reach ketosis is by measuring your ketone levels. We’ll get to the how of it in a minute.

If you can eat some carbs and remain in ketosis, you might want to consider eating them before or after your workouts. Timing your carbohydrate intake like this is called the targeted ketogenic diet.21 Compared to a standard ketogenic diet, it may improve your energy levels during training and help you recover from your workouts.

A common practice is consuming carbs and a protein shake after a workout. However, research shows that the carb part is unnecessary to stimulate muscle growth.22 23 Twenty to thirty grams of protein in your post-workout shake or meal is enough to stimulate muscle protein synthesis, and adding carbohydrates does nothing.

Fill up with Fats!

On the ketogenic diet, the primary fuel source for your body is fat. That means increasing your dietary fat intake tremendously. Once you’ve determined your protein intake and how many carbs you can eat, the rest of your calories will come from fat.

Figuring out how much fat you should eat is easy. Let’s say you’ve determined that you need 2,500 calories per day and that you’re aiming for 150 grams of protein and 50 grams of carbs.

Protein and carbohydrates both provide you with four calories per gram. That means you’ll be getting 800 calories (200 x 4)  from protein and carbs combined in this example.

That leaves 1,700 calories you need to get from fat.

Each gram of fat provides you with nine calories. 1,700 divided by 9 gives you approximately 190 grams of fat.

In conclusion, your daily macronutrient plan would then look like this:

  • 2,500 calories total
  • 150 grams of protein
  • 50 grams of carbs
  • 190 grams of fat

There you have it! Adjust the number to your own calorie requirement and body weight, and you’re good to go.

How to Make Sure You’re in Ketosis

If you want to make sure you’re in ketosis despite eating a lot of protein or want to know if your carb intake is low enough, there are several ways you can check your ketone levels. They show you if you are in ketosis or not.

  • Using urine strips is a convenient and inexpensive way to check if you’re in ketosis. They let you measure your ketone levels with a simple home test. You simply pee on a strip, and it’ll tell you the levels of two different ketones in your urine.
  • A blood ketone meter is a more accurate method than using strips. It is also more expensive. You prick your finger just like with a blood glucose meter. Instead of checking your blood sugar, it shows your blood ketone levels. Of course, you need to be able to handle the sight of blood to use it.
  • A breath ketone meter lets you measure your levels of the ketone acetone. It’s a convenient and accurate way to see if you’re in ketosis without having to draw blood.
  • The most accurate way is to have a blood test through a doctor, but that would get very expensive very quickly.

Nutritional ketosis means blood ketone levels of 0.5 to 3 mg/dL.24 Any of these methods make sure you’re in that range.

Great Foods for Building Muscle on Keto

These are some kitchen essentials for building muscle on keto. Make sure you’re well-stocked!

  • Fish and seafood. Both canned goods like tuna, mackerel, sardines, and fresh or frozen fish like salmon are healthy and muscle-building food. Lean fish is excellent too, but fatty fish give you both quality protein and fats in the same convenient package.
  • Meat, including both red and white meat. Beef, pork, lamb, game, chicken, turkey, etc. Don’t be afraid of the fattier cuts. On the contrary, these are often the better choice for a ketogenic diet and usually the most inexpensive.
  • Low-carb vegetables, fruits, and other plants. Fibrous vegetables without too much starch can be part of your ketogenic diet. Broccoli and cauliflower are low-carb, and you can include them as part of your diet in moderate amounts. In moderation, you can also use spinach, arugula, asparagus, cabbage, cucumbers, tomatoes, kale, and bell peppers.
  • Avocado and olives are two fatty fruits popular amongst keto-fans for a good reason.
  • Nuts and seeds. All kinds of nuts, seeds, and almonds are a great addition to a keto diet. They are low in carbs and high in fat and protein. The fat quality varies depending on the nut, and the protein doesn’t have the best amino acid composition. Still, as a part of your diet as a whole, they are valuable and provide both energy and nutrients.
  • Eggs are the complete package. Almost. They lack vitamin C but provide you with most other nutrients you need for building muscle. Perfect both as a main dish and in cooking.
  • Dairy products. Milk, cottage cheese, curd, quark, hard and soft cheeses, yogurt, and butter are rich in either protein or fat, or both, and in most cases also provide plenty of calcium. If you aren’t intolerant to dairy, milk products give you access to the most muscle-building proteins of all. You get some milk sugar from regular milk, so make sure you don’t go overboard.
  • Pure fats. Olive oil, rapeseed oil, nutty oil, avocado oil, coconut oil, and good old butter are pure fat sources suitable for cooking and for adding to any recipe to increase the fat content.

Sample Meals

You don’t have to base your diet on bacon and eggs just because you’re doing keto. Of course, everything’s better with bacon, but don’t base your entire diet around it.

Here are a few examples of complete meal suggestions that can be a part of a healthy ketogenic diet. These meals are rich in nutrients, and hopefully, they sound appetizing as well.

  • Mackerel in tomato sauce with scrambled eggs, a green salad, and fresh tomatoes
  • Ground beef patties with onions and gravy and oven-baked root vegetables
  • Cauliflower pizza with mozzarella cheese and bacon
  • Oven-baked salmon with parmesan cheese and cream on a bed of spinach
  • Meatloaf made with cream and eggs + brown gravy + green string beans
  • Chicken thigh casserole with creamy sauce and mixed greens

These meals give you enough protein to give your muscles what they need to grow and fat to fuel your workouts.

Training to Build Muscle on Keto

How should you adapt your strength training for a keto lifestyle?

You shouldn’t. One of the selling points of the ketogenic diet is that you can live your life, as usual, but without carbs. A training program for building muscle looks the same whether you’re on a ketogenic diet as a high-carb diet.

Regardless of your diet, you have to hit the weights hard to gain some serious muscle, though!

  • Practice progressive overload in your training. Always try to increase the weight you use or do a rep more with a certain weight.
  • Anything between 3 and 30 reps works for building muscle. From a practical standpoint, 6–15 is a good starting point. Always using heavy weights taxes your joints, and high-rep training to failure is mentally exhausting.
  • You should perform at least ten sets per muscle group and week if you want optimal results in the form of muscle growth.
  • It doesn’t matter much if you work a muscle once or five times weekly, as long as your total weekly training volume is the same. You benefit from spreading your training volume over several workouts if you’re into high-volume training. Otherwise, the quality of your sets might suffer.
  • Rest two minutes or longer between sets.
  • Include a variety of exercises to target your muscle from different angles, and mix and match compound movements and isolation exercises instead of relying solely on one or the other.

Those are essential strategies for maximizing muscle growth.25 Keep them in mind, and you’ll build muscle, regardless of how you eat, as long as you eat enough.

Read more: How to Build Muscle: Exercises, Programs & Diet

Training Programs for Building Muscle

If you’re looking for a new training program tailored to your experience level or just want a change from your old routine, we have several effective programs for building muscle.

  • Beginner Barbell Program, three days/week: A time-efficient training program for beginners looking to gain muscle. If you’re new to strength training and looking to gain muscle and strength, you can’t go wrong with this barbell-based program based on compound movements involving several large muscles simultaneously. You work out three times per week, performing three exercises per workout.
  • Beginner Machine Program, two days/week: As an alternative to our barbell program for beginners, this program introduces you to strength training using machines instead.
  • StrengthLog’s Full Body Hypertrophy, three days/week: This is a training program for intermediate levels and above, where you train your entire body three times per week. Each training session is unique, working all muscle groups with a wide range of repetitions to stimulate hypertrophy.
  • StrengthLog’s Upper/Lower Program, four days/week: This program is a great way to start if you want to train four days per week. It’s pretty minimalistic using only compound movements, but you can add isolation work according to your preferences.
  • Bodybuilding Ballet, 4–6 days/week: Our most popular and advanced training program for building muscle. Train like a bodybuilder for maximum muscle growth. Not for beginners.
  • Bodybuilding 313 – a Training Program for Bodybuilders, 5–6x/week: A classic three-day training split, in which you train three days, rest one, train three, and so on. Many top bodybuilders have used such a program throughout the decades.

All these programs, and many more, are available in our workout tracker StrengthLog, which is free to download for both iOS and Android.

Download StrengthLog Workout Log on App Store
Download StrengthLog Workout Log on Google Play Store

Of course, if you’re already following a resistance exercise program you like, feel free to continue using it. A training program that is effective on a standard high-carb diet is also effective on keto.

Designing your own program? Check out Top 20 Bodybuilding Exercises for Every Muscle Group for guidance and inspiration.

The Keto Flu

When you go keto, it takes some time for your body to adapt to the lack of carbohydrates in your diet. Many feel awful during this time, which can last for up to four weeks. It’s often called “the keto flu.” It’s not an actual disease, and you’re not really sick, but it sure can feel like it.

The keto flu is not a medical condition. Therefore, it’s not described in the medical literature. It’s probably caused by several factors, notably low sodium levels in combination with dehydration and your brain not getting its usual preferred fuel.

Keto lowers your insulin levels, which is a good thing, but low insulin levels also make you retain less sodium. 

Carbohydrates stored as glycogen retain a lot of water, so when your glycogen stores decrease, you also lose plenty of water.

While you probably can’t skip this transition period altogether, you can mitigate the adverse effects.

  • Be sure to drink enough water. Don’t gulp it down by the gallons, but don’t go dehydrated. Drink enough to satisfy your thirst and a little extra during and after exercise.
  • Don’t eat a low-sodium diet. Add some salt to the foods you eat. While cutting down on sodium might be a good idea for someone eating a standard western diet, you’re already losing a lot of sodium when you start a ketogenic diet. During the first weeks of keto, I suggest you get at least 5 grams of sodium per day to mitigate that.
  • If you’re active and exercise a lot, you could also add potassium and magnesium to your regular diet. I’d suggest 200–300 mg magnesium and 500–1,000 mg of potassium in addition to the amounts you get from foods. These amounts have no adverse effects and ensure your body has enough during these taxing weeks.

The keto flu is no fun when you’re trying to get some high-intensity workouts done. Therefore, you might have to lower your training intensity or volume for a week or two while you adapt to keto. However, hang in there, and you’ll soon feel better, get your energy levels back, and be ready to hit the weights hard again.

Supplements to Gain Muscle on Keto

Dietary supplements aren’t necessary for muscle building. However, they can help you perform better in the gym and make it easier to pack on the muscle.

Creatine

No supplement is backed by more research than creatine. Creatine helps you perform better, become stronger, and gain more muscle.

Read more: Creatine: Effects, Benefits and Safety

Caffeine

For high-intensity training sessions, caffeine is a great pick-me-up and a tried and true energy boost. It won’t kick you out of ketosis, either.

Read more: Caffeine: Effects, Benefits, and Safety

Exogenous Ketones

You can boost your ketone levels by using an exogenous ketone supplement. By doing so, you can lower your appetite and even improve your exercise performance.26 27

Protein Supplements

When you need a convenient and inexpensive way to boost your overall protein intake, a quality protein powder, like whey, casein, or soy protein, is always good to have at hand.

Read more: Whey or Soy Protein for Building Muscle?

Want to learn more about dietary supplements? Which ones are worth your money, and which are questionable or useless? Check our StrengthLog’s Supplement Guide, our free guide where I review 26 of the most popular supplements.

Summary

The ketogenic diet is a viable alternative to standard high-carb diets for building muscle.

Research shows that it might not be 100% optimal, mostly because you might find it challenging simply to eat enough food, but if you follow the guidelines in this article, you can make it work.

Eat enough calories and plenty of protein, keep track of your carbs and hit the weights like there is no tomorrow. You’ll give your body what it needs to respond to your efforts, and the result is muscle growth.

References

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  12. Front. Nutr., 20 August 2019. Is an Energy Surplus Required to Maximize Skeletal Muscle Hypertrophy Associated With Resistance Training?
  13. Int. J. Environ. Res. Public Health 2014, 11(2), 2092-2107. Ketogenic Diet for Obesity: Friend or Foe?
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  15. Br J Sports Med. 2018 Mar;52(6):376-384. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults.
  16. Ann Nutr Metab 2010;57:59–67. Metabolic and Appetite Hormone Responses of Hyperinsulinemic Normoglycemic Males to Meals with Varied Macronutrient Compositions.
  17. The Journal of Clinical Endocrinology & Metabolism, Volume 85, Issue 5, 1 May 2000, Pages 1963–1967. The Effects of Carbohydrate Variation in Isocaloric Diets on Glycogenolysis and Gluconeogenesis in Healthy Men.
  18. Diabetes Educ. Nov-Dec 1997;23(6):643-6, 648, 650-1. Protein: metabolism and effect on blood glucose levels.
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  20. StatPearls Publishing; 2022 Jan. Ketogenic Diet.
  21. Indian J Med Res. 2018 Sep; 148(3): 251–253. Ketogenic diets: Boon or bane?
  22. Am J Physiol Endocrinol Metab. 2007 Sep;293(3):E833-42. Coingestion of carbohydrate with protein does not further augment postexercise muscle protein synthesis.
  23. Medicine and Science in Sports and Exercise, 01 Jul 2011, 43(7):1154-1161. Carbohydrate does not augment exercise-induced protein accretion versus protein alone.
  24. Curr Nutr Rep. 2018 Sep; 7(3): 97–106. Nutritional Ketosis for Weight Management and Reversal of Metabolic Syndrome.
  25. International Journal of Strength and Conditioning, 1(1), 2021-08-16. Resistance Training Recommendations to Maximize Muscle Hypertrophy in an Athletic Population: Position Stand of the IUSCA.
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  27. Cell Metab. 2016 Aug 9;24(2):256-68. Nutritional Ketosis Alters Fuel Preference and Thereby Endurance Performance in Athletes.
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Andreas Abelsson

Andreas has over 30 years of training experience and is a highly appreciated writer and educator on exercise, fitness, and nutrition. Few people stay more up to date and have a better grasp of the field of exercise science than Andreas.