Is building muscle on keto possible? Or does going low-carb always mean you’re bound to experience muscle loss?
When it comes to the connection between the keto diet and muscle loss, findings from various studies might surprise you. There’s now good evidence that when done correctly with the right keto diet foods and paired with the right types of exercise, building muscle on keto is far from impossible.
In fact, the keto diet has been associated with:
Is it possible to build muscle on a keto diet?
First let’s tackle the general question: Can you build muscle on a low-carb diet? (Is building muscle on keto possible?)
For many decades, most athletes and bodybuilders assumed that eating adequate carbs was an essential part of putting on muscle mass and preventing muscle loss. The rationale behind this argument is that carbs increase the release of insulin, an anabolic hormone that ushers energy into muscle cells and helps muscles to grow.
On low-carb diets, it’s long been thought that significant loss of muscle mass might occur because the body pulls amino acids from muscle protein in order to keep some glucose in the bloodstream, via the process gluconeogenesis.
However, studies have made it clear that only minimal carbs and glucose are actually needed to support muscle growth, not the typical amount of carbs that most people eat. And, assuming you’re eating enough calories and protein, your body can make enough glucose in small amounts — plus use fatty acids— to power your muscles.
After an initial period on the ketogenic diet, you become what’s called “keto-adapted,” which means your body uses your stored body fat and the fat from your diet for energy. Being keto-adapted allows you to synthesize energy from fat in the form of adenosine triphosphate (ATP), which is what powers your muscles, brain and other organs.
Being in ketosis can also help prevent muscle loss to some degree, since in ketosis your body (including your energy-guzzling brain) uses ketones from fat for energy rather than protein from your muscles.
Because of this, as a 2006 article published in the journal Nutrition and Metabolism put it, “a number of studies indicate that a [very low carbohydrate diet] results in body composition changes that favour loss of fat mass and preservation in muscle mass.”
Results from other studies also have indicated that weight loss on the keto diet tends to be rapid, consistent and mostly from body fat stores, especially when compared to other low-calorie diets that include less fat.
For example, a 2002 study published in Metabolism found that a very-low-carb diet resulted in a significant reductions in fat mass and an accompanying increase in lean body mass in normal-weight men. The men switched from their normal diets (around 48 percent carbohydrates) to a carbohydrate-restricted diet with about 8 percent carbohydrates for six weeks.
During this time the men were told to consume adequate calories (dietary energy) to maintain their body mass. Researchers involved in the Metabolism study believed that the positive changes in the men’s body composition may be due to a reduction in circulating insulin levels.
There are also other theories as to how ketosis preserves muscle mass, such as: The keto diet increases adrenaline and beta-hydroxybutyrate (a major ketone body), decreases leucine oxidation, and promotes protein synthesis — and that the keto diet increases growth hormone levels, which stimulates muscle growth.
Can you work out on keto? Definitely, and you should!
As discussed more below, strength training is an important part of building and retaining muscle on the keto diet (and other diets, too).
Given what we know about low-carb diets supporting muscle growth, do bodybuilders ever do keto? Because ketosis has benefits beyond supporting muscle growth — such as controlling hunger, improving mental clarity and protecting against chronic diseases — we’re now seeing many more ketogenic bodybuilders who are advocating for the low-carb, high-fat lifestyle.
Building muscle on keto
Want to know how to lose fat and gain muscle on keto? Here are tips regarding calorie and macronutrient intake, along with workout suggestions, that will make building muscle on keto easier:
1. Be patient
When first starting the keto diet and transitioning into ketosis, you can expect that you may need to essentially take a step back before taking two steps forward. During the first couple weeks of the keto diet, when your body is going through metabolic changes in order to become keto-adapted (or “fat-adapted”), a decrease in strength, performance and motivation is not uncommon.
You might also lose some water weight initially due to cutting carbs. With time, your body gets used to being in ketosis and producing more ketone bodies, so symptoms should only be temporary and last for about one to two weeks.
Here’s the good news: If you stay patient and ride out any temporary “keto flu symptoms” that might come up, you’ll wind up improving your metabolism for the long term as well as your body’s ability to generate and use energy.
2. Strength-train regularly
What’s the best way to gain muscle on keto? Many will tell you that it’s strength training.
Doing resistance training while following the ketogenic diet helps build and retain lean muscle mass. At the same time, this type of regimen can help prevent fat gain, even when you’re eating to satiety.
The amount and specific type of strength training you should do depends on your goals, but a general recommendation (such as from the American College of Sports Medicine) is to do at least two to three sessions of resistance training per week, in addition to some metabolic/aerobic training.
Five days per week may be a better goal for more advanced lifters. Either way, try to target most of your major muscle groups, such as by performing exercises like weighted squats, bench presses, leg abductions, lat pull-downs, lunges, etc.
3. Make sure you eat enough calories
When it comes to building muscle on keto, consuming adequate calories is key, since at the end of the day your body needs calories to grow new tissue. Under-eating calories, especially while training regularly, also makes it more likely that you’ll experience fatigue and decreased performance.
If muscle growth is your primary goal, as opposed to weight loss, be sure to eat at or above your “maintenance calories” mark. You don’t need to go nuts, but aim to consume about 200–500 extra calories per day than you’d need to simply maintain your current weight.
Focus on getting these extra calories from healthy keto fats and also protein foods — such as olive oil, coconut oil, eggs, fatty fish, ghee, butter, etc.
4. Consume minimal carbs but enough protein
The ketogenic diet is different than many other low-carb diets because it’s very high in fat but only includes moderate protein. The reason the keto diet normally doesn’t include lots of protein — let’s say as much as some typical bodybuilding diets — is because your body can turn excess protein into glucose, a process called gluconeogenesis.
Gluconeogenesis occurs in mammals and other organisms when glucose from carbohydrate foods is unavailable as a way of sustaining life by creating glucose from non-carbohydrate precursors (fats and protein).
This leads people on the keto diet to fear that they will be kicked out of ketosis if they overeat protein, even if they are strictly watching their carb intake. However, it’s important to point out that we do need at least some glucose to power our organs and cells, so a small amount of gluconeogenesis is not a bad thing, especially if you’re active.
The key here is to eat enough protein to support growing muscles but to still keep carb intake low and fat intake high.
How much protein do you need on the keto diet? A good rule of thumb: Protein intake should be between one and 1.5 grams per kilogram of your ideal body weight.
To convert pounds to kilograms, divide your ideal weight by 2.2. For example, a woman who weighs 150 pounds (68 kilograms) should get about 68–102 grams of protein daily.
Some recommend a bit more, such as eating about one gram of protein for every pound of lean muscle mass (which is your total body weight minus your body at percentage).
5. Supplement to support higher energy levels
One thing you can do to lower the chances that you’ll deal with fatigue and poor exercise recovery is to supplement, including with exogenous ketones and/or electrolytes.
If you’re not familiar with exogenous ketone supplements, these provide ketones that come from outside the body. They mimic the effects of ketones that are naturally produced by your body when you’re in ketosis.
Benefits associated with ketone supplements include:
While there are three types of ketone bodies, the ketone found in exogenous ketone supplements is usually only or mostly beta-hydroxybutyrate. Ketone supplements can be used in between meals or as a beneficial preworkout food that will provide you with a quick source of ketones.
You can also use ketone supplements to help you get back into ketosis more easily and quickly if you’ve abandoned the diet for a period of time.
Let’s not forget about electrolytes, which are also important for keeping your energy up and muscles working properly.
Add bone broth to your daily regimen, which can help restore electrolytes that are lost during ketosis. Be sure that you’re drinking a lot of water and other keto drinks, since you will lose water weight and also flush essential electrolytes out of our system, including magnesium, potassium or sodium, due to increased urination on the keto diet.
Additionally, emphasize foods that help increase electrolyte intake, such as nuts, avocados, mushrooms, salmon and other fish, spinach, artichokes, and leafy greens.
For the best results, avoid eating ultra-processed foods like refined oils, cold cuts/processed meats (especially pork) or cured meats, bacon, and processed cheeses. However, don’t be afraid to add some real sea salt to meals, since sodium is an important mineral that you may be losing too much of on the keto diet.
More tips for building muscle on keto
To really maximize ketone production and enhance effects like fat-burning and building muscle on keto, you can combine a ketogenic diet, intermittent fasting, strength-building exercises and exogenous ketones. After about one to two months on the keto diet, you may also want to experiment with carb cycling depending on your fitness and body composition goals.
Want to know how to build muscle on keto if you’re also practicing intermittent fasting? The same rules as above for building muscle on keto still apply in this case.
You should continue to do some strength training, eat enough calories and protein, watch your carb intake, and use keto supplements if you find them helpful.
Because it can be hard to train while fasting, you may need to tweak your schedule so your tougher workouts fall on days/times when you’re eating more. And you might consider keeping a food journal if you suspect that fasting is leading to decreased calorie intake, which makes building muscle on keto much more difficult.
