Keto and Muscle Building: Is It Possible?

Guys, I’m in the trenches. That’s why you haven’t seen me around.

As quickly as the craze of plant-based eating has risen, the trend of low-carb, carnivore, paleo, and ketogenic eating is also making an insidious surge in use. 

Now, I’ll save my soapbox for another time about these diets being popular mainly because the more unconventional something is, the more views it gets on social media and more clicks = credibility in today’s social currency. 

So let’s just start with what the keto diet is. In order to adhere to a ketogenic diet, it is necessary to drastically reduce your carbohydrate intake, which in turn, causes your body to enter a state of metabolism known as ketosis. 

Ketosis is essentially a survival mechanism the body has adapted to revert to when glucose availability is low, since glucose is the brain’s preferred source of fuel, but it’s also most readily available from carbohydrates.

When glucose is low, the body begins to convert fat into something called ketone bodies, which can be used as an alternative fuel source to glucose. When enough of these ketone bodies are being generated, the body is in ketosis. 

The theory behind being in ketosis is that, by reducing your carb intake to as low as 50 grams of carbs or less per day (the equivalent of about 1 bagel), it will force the body to burn body fat for energy. 

Now, spoiler alert, this isn’t how it works. There are way more pleasant and practical ways to burn fat. But I digress. 

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Is it Possible to Build Muscle on Keto?

You may be wondering why this is a debate in the first place. 

Well, generally speaking, the traditional bodybuilding diet for someone trying to bulk up is to eat plenty of protein, but twice as many carbohydrates. Carbs serve a critical purpose in muscle sparing which means your metabolism will burn through the carbs before your muscle tissue thus helping to keep muscle gains in a net positive. 

A good ol’ carb source also promotes muscle building to give you a burst of energy to crush your resistance training. So, it seems like it would be darn near impossible to get gains on keto, right? 

Well, let’s see what the science shows. 

One famously cited study published in the Journal of the International Society of Sports Nutrition showed that those on the keto diet gained double the muscle and burned significantly more fat than those in a high-carb diet. 

However, the full data of this study has never been released, so we don’t really know if this is the full story. Let’s look elsewhere. 

There was also a study involving 22 female weightlifters who trained four times weekly and undertook either a keto or non-keto diet for a period of eight weeks. It was concluded that the keto group lost fat, but they also lost muscle while the non-keto group gained strength, but not muscle.

So what gives? Neither group were eating enough calories, which explains the fat loss in the keto group and the lack of muscle gain in the non-keto group.

The authors posited that a calorie surplus would have results in gains in lean mass, but that the satiety brought on by the high-protein, high-fat nature of keto can make reaching this surplus difficult.  

In a different study, it was confirmed that, when sufficient calories were consumed, non-keto dieters gained 5 pounds of muscle while keto dieters gained none, but still lost fat. 

And most studies showing this phenomenon show similar results, with others coming to the conclusion that the lack of carbs in the keto diet isn’t the only thing that may hinder your muscle building. The diet may also cause a decrease in muscle building hormones like testosterone. 

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So, How Can You Build Muscle on the Keto Diet?

I gotta start this message by saying I don’t advise you use this diet for muscle building. Science shows that the diet can work against you in many ways. First off, protein is the most satiating of the macronutrients, meaning it promotes the most profound feeling of fullness. 

Without carbs in your diet, you’ll find yourself eating way more protein and fat, which both digest slowly in the stomach compared to carbs. Since you have to be in a calorie surplus to effectively gain muscle, this makes eating enough calories in a keto diet can be downright unpleasant. 

If you’re a sadist, though, it can be possible to still build muscle on low-carb. First, make sure you’re eating more than you’re burning along with eating sufficient protein, which shouldn’t be an issue as long as you’re doing keto right. 

You want to focus on lean sources of protein like nonfat dairy and lean meats. It’s tempting on keto to gorge yourself on butter and bacon, but having these things regularly cause inflammation in the body that makes gaining muscle exponentially more difficult. 

It also just makes you feel like crap, which is already a common symptom of keto, especially when you’re first starting out. 

People bulking on high-carb find it easy to eat in a calorie surplus because carbohydrates digest much more quickly than the foods included in a low-carb diet. This is another reason why it’s a good idea to choose low-fat meats, as high-fat protein sources keep you fuller for longer and make it more challenging to eat enough food. 

Nobody wants to be slinging weights around when they feel bloated and heavy all the time. 

The bottom line?

Among all the diets to follow to build muscle, keto isn't at the top of my list. Not only are you missing out on the muscle sparing properties of carbs, but the low energy you may experience due to a lack of glucose can make resistance training feel much harder. 

Furthermore, science shows that non-keto dieters gain muscle much more easily, likely because sufficient carb intake keeps muscle building hormones at optimal levels and high-carb diets make hitting calorie goals much easier. 

Whether you’re keto or low-carb, though, if you need some guidance on how to build muscle, let me calculate your macros. If you want even more guidance, check out my easy recipes and meal plans for muscle building.