The Pete Gawtry Fitness guide to Building Muscle on Keto

Right now, Keto is popularly known as a diet for weight loss. I am here to tell you that it need not be restricted to that specific purpose.

I am aware that thousands of studies and testimonials substantiate the fact that a ketogenic diet is extremely effective in facilitating and sustaining weight loss, and in no way am I contesting this idea. My argument is that this diet has more benefits, which must not be overlooked.

For those of you who are into sports or are committed to building some muscle and strength, this diet is extremely resourceful. There is a common misconception among fitness freaks that since keto diet isn’t exactly pushing people to stock up on proteins, it is challenging to build muscles.

Is this belief true or does it hold any merit? Or, is keto diet something that bodybuilders must consider?

This article will help bust several myths surrounding the keto diet. I will primarily focus on proving to you that it is, in fact, possible to build and maintain a muscular frame, while complying with the principles of a ketogenic diet.

However, let us begin by looking at how muscles can be built.

Muscle Protein Synthesis

Our body uses the process called muscle protein synthesis (MPS) to develop new proteins, which is imperative to increase muscles. The process of gaining muscle mass is known as muscle hypertrophy.

Protein synthesis is handled by a set of biochemical pathways, which are activated by nutrients as well as exercise. However, there are specific types of exercises that promote muscle growth.

Resistance exercise helps in overloading the muscle, which enhances muscle protein synthesis.

Simply put, weightlifting is essential to “get big.” How does that work?

mTOR and Muscle Building

Several researchers who are studying longevity are demonstrating interest in the mammalian target of rapamycin (mTOR). Interestingly, this cellular sensor plays a crucial role in muscle hypertrophy and protein synthesis as well.

What is mTOR? To begin with, it is a nutrient sensor. That is, it can identify if the body has been fed or not.

Mechanical forces are also sensed by mTOR. This is significant information as it facilitates the sensor’s involvement in hypertrophy. mTOR is activated every time we lift weights and a muscle is overloaded consequently. When mTOR is activated, it performs two functions. Firstly, it leads to muscle protein synthesis. Secondly, it helps prevent protein breakdown. Thus, it is extra effective in building muscle.

Understandably, if you activate mTOR more, your muscle growth and strength is enhanced. It’s a classic dose-response effect.


Hormones, known as growth factors, can also activate mTOR. Both insulin and insulin-like growth factor activate mTOR, thereby stimulating muscle protein synthesis.

Amino Acids are Necessary

As we all know, proteins are made up of amino acids, which is why they are commonly known as the “building blocks” of proteins. In short, it is impossible to build muscle without amino acids.

The branched-chain amino acids (BCAAs) are particularly helpful in growing and maintaining muscle mass. They are popularly referred to as Essential amino acids, as our body does not produce them. Instead, we must consume them.

When we consume BCAAs, particularly the BCAA leucine, muscle protein synthesis is stimulated through mTOR. According to research, the BCAAs are instrumental in facilitating muscle hypertrophy as well as the prevention of loss of muscle, more so than insulin.

After an intensive workout, people are pushed to consume more proteins for amino acids. Amino acids will optimize muscle protein synthesis and are also a great way to revive from the hard day. It cannot be denied that overall protein balance is very important for muscle protein synthesis. However, a few studies have concluded that consuming 20 – 30 grams of good proteins post-workout, will optimize protein synthesis. It is important to consume at least 2 grams of leucine, which is extremely useful in protein synthesis.

Are Carbs Necessary to Build Muscle?

In the bodybuilding sector and among athletes, keto has been discouraged actively by many, due to the low intakes of carbs. The fact that both insulin and IGF-1 increase when carbs are consumed has led to the belief that they are necessary for muscle growth.

A large population also recommends athletes to ingest a combination of proteins and carbohydrates after a workout, if they want to enjoy optimal benefits. The idea behind this recommendation is that as carbohydrates activate insulin, it enhances muscle protein synthesis, as opposed to when only protein is consumed.

Interestingly, several studies have compared muscle protein synthesis that occurred when only proteins were consumed, and when a combination of proteins and carbs were consumed post-workout, and no difference in muscle protein synthesis was observed. Simply put, carbs did not enhance the process. It may be because proteins were adequate to increase insulin and thus, activate mTOR. Thus, in this scenario, increased insulin does not equal more protein synthesis.

Thus, this a strong argument against those who discourage the use of keto to build muscle. However, there is another vehement argument against the use of keto for athletes and it is related to the glycogen.

People argue that the workout may be hampered if there aren’t adequate glycogen stores. Needless to say, no athlete would be keen on it. It is important to understand that glycogen depletion is more of a problem for athletes engaging in endurance activities. Therefore, athletes who align towards bodybuilding or weightlifting probably will not experience problems due to low glycogen.

Moreover, according to data, there isn’t substantial evidence that keto diet decreases glycogen levels, especially after following it over a substantial period of time.

Moreover, the stored muscle glycogen level was similar in athletes who adopted a keto diet as well as those who consumed about 600 grams of carbohydrates each day. Although the former consumed almost 75% fewer carbs during the study, it was observed that they could replenish their stored glycogen levels at a rate similar to the other group, after exercise. Clearly, keto-adapted athletes undergo something, for their bodies to continue regulating their glycogen levels. Let us understand this better.

A process called gluconeogenesis (GNG) helps in maintaining glucose and glycogen levels in the body when carbs are not consumed. In this process, non-carbohydrate sources such as amino acids and glycerol are used to produce glucose.

In this manner, athletes consuming low carbs are still able to match up to others, when it comes to maintaining their glycogen levels.

Clearly, this is a strong argument against those who claim that carbs are required to build muscle or maintain the required level of glycogen when engaging in athletic activities.

However, this article aims to focus on muscle growth. So let us look more closely at that.

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How Keto Helps You Build Muscle

Why did the idea that a keto diet does not promote muscle growth become so popular?

For beginners, it is commonly believed that consuming low carbohydrates will lead to inadequate stimulation of insulin/IGF-1 after a workout.  Thus, your body will not be able to stimulate muscle growth and may even contribute to muscle loss. Thus, a lot of people believe that unless carbs are consumed along with proteins, muscle protein synthesis is not optimized.

Secondly, people argue that in a ketogenic diet, protein is consumed in moderation, at about 10 – 15% of aggregate calories. Proponents of this argument express that as protein is integral to build muscle, minimizing its consumption may retard muscle growth.

However, I personally disagree with both arguments.

There hasn’t been substantial research done on this topic. However, there is some evidence that a keto diet is beneficial in building muscle mass and maintaining it.

Get Lean

Obviously, bodybuilding is the goal for many. However, most strength-based athletes also like to focus on their body composition, which can be optimized using a low-carb high-fat diet. According to studies, athletes on a keto diet lose more fat in comparison to those who eat more carbs.

Both keto diet followers and non-keto groups participated in a resistance training program for eight weeks. It was observed that the former demonstrated a decline in body fat and visceral adipose tissue, while the latter did not.

Understandably, following a keto diet and equipping yourself with tools required to burn fat to gain energy, would lead to a decrease in the body fat.

In simple terms, once you are adapted to keto, you will find it easier to lose bodyweight and fat from food.

When there is an increase in the burning of fat and the lean mass is maintained in the body, the body composition improves, leading to increased lean muscle and less fat.

Protein Breakdown Prevention

It is a popular belief that when an individual does not consume adequate protein, they end up losing muscle and become extremely thin. This is commonly used against keto diet as people argue that there isn’t adequate protein in the diet to maintain muscle mass.

Interestingly, studies have substantiated that this diet prevents the breakdown of the muscle. When people have consumed the same number of calories in their diets, with a stable amount of protein and a varying amount of carbs, the results were as we had previously argued. Those who consumed lesser carbs demonstrated maintenance of lean muscles to the optimal level.

Moreover, one might find it easier to use up proteins when they follow a keto diet, probably because protein is not used up for gluconeogenesis, as ketones are used instead. Protein synthesis and muscle maintenance are enhanced when ketones are infused, as BCAAs are not used as extensively for energy.

Hence, ketones save up proteins and also contribute to the enhancement of muscle protein synthesis. It was observed that people who consumed a ketone-based supplement consisting of a BHB monoester, demonstrated enhanced activation of mTOR, consequently doubling protein synthesis.

Now, the question that arises is, what is the effect of a ketogenic diet on athletes when they are training? Does the research prove that there is an increase in muscle mass?

With the rising popularity of this trend among athletes, there is increased interest in the area among researchers about its effectiveness.

A particular study was conducted, wherein conventional and keto diets were compared for ten weeks, wherein healthy young males underwent resistance training. After commencement of ten weeks, those who were on low carbs showed an increase in the lean body mass (2.4%) while their fat decreased by about 2.2 kilograms, which wasn’t very different from what the other group demonstrated. Moreover, the low-carb group also demonstrated increased testosterone. Thus, this study proved that when keto diet is coupled with strength training, it is ideal for increasing lean muscle.

Moreover, two other studies have substantiated that the keto diet maintains muscle mass even during training, although critics argue that it results in the loss of muscle.

In the first study, a few gymnasts adopted a keto diet as they continued to engage in their training sessions. By the end of the experiment, it was observed that although there was no difference in the muscle mass, they burned substantial fat to build lean muscle.

In the second study, athletes in a CrossFit program followed a ketogenic diet for six weeks. Similar to the previous study, although they did not see a difference in their muscle mass, there was a substantial decrease in their body fat and fat mass.

Moreover, it is important to note that in both cases, these athletes maintained their performance. As discussed already, people discourage keto diets stating they may affect high-intensity performance measures, wherein high glycolytic capacity is required.

However, research has evidenced that when keto diet is coupled with a resistance training program, it can decrease body fat and enhance lean muscle mass.

This is an interesting area for research, as there is adequate scope to assess the role of the keto diet in building muscle.

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Don’t Fear THE Protein

In keto diet, the focus is largely on carbs. However, it does not completely ignore proteins. Although it does not encourage high consumption of proteins, one need not resort to low-level of proteins either. As a matter of fact, keto pushes for moderate consumption of proteins.

Let us look at a few numbers. Imagine proteins account for about 15% of your calories per day. Now, if you are consuming 2500 calories each day, which is 93 grams of protein. Although those who are dedicated to muscle-building may argue that it isn’t a lot of protein, it isn’t a small number either.

While on a keto diet, you can even consume about 20 – 25% of total calories as your proteins. A few people may still follow a keto diet, without limiting their protein intake, particularly among high-activity athletes.

However, increased intake of protein may eliminate ketosis as gluconeogenesis is initiated. However, this is still a controversial topic as several studies have claimed that increased protein intake does not necessarily increase GNG to a level that ketogenesis is halted. The process of GNG is gradual, and following a meal, the production of glucose does not depend a lot on protein content or breakdown. A particular study evidenced that eating proteins did not accelerate GNG even under “optimal gluconeogenic conditions”.

There may be individual differences when it comes to the impact of varying protein levels on a keto diet. That being said, you can consume more protein while on a keto diet if you are looking to build muscles.

Get Started

Hopefully, you picked up one or two interesting points from this article, which changed your preconceived notions about the keto diet. According to studies, the keto diet contributes to increased, as well as, maintained muscle mass, especially in those who train while on a keto diet.

If you are following a proper diet and consuming healthy fats in the right amount, it is possible to attain ketosis and build muscle. A proper ketogenic diet can help achieve diverse goals such as lifting heavier weights, gaining muscle, or even becoming bulkier.

You can look up hundreds of people on YouTube and Instagram, who are not only following a ketogenic diet but are also becoming leaner and building muscle. Although it is not scientific evidence, it is still important to consider.

If you would like a bespoke Keto meal plan – click here


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