The keto (or ketogenic) diet is fast becoming one of the most popular dietary approaches in the world.
While many will use it to help manage their weight, it may also be of benefit to those looking to build more muscle.
In this article we’re going to cover what exactly the keto diet is, misconceptions regarding keto and muscle building and how the keto diet can actually help us to build muscle.
What is the keto diet?
The keto diet is a high–fat, low–carbohydrate diet that’s often accompanied by increased protein intake.
It was originally created to help reduce the severity and frequency of seizures for those who suffer with epilepsy. More recently it has been implicated as a viable weight–loss diet and may be of benefit to those with metabolic conditions too.
The keto diet is focused around the goal of achieving ketosis and minimising insulin production. Ketosis is the state in which we are so carb depleted that our body will use dietary fat and or fat stores for energy.
The body breaks down fat to produce ketones (hence ketosis) which can enter the energy cycles to produce energy. It typically takes around 3–4 days of a very low carb diet (sub 50g a day) to achieve ketosis.1 For some it can take as much as a week!
This is arguably the toughest hurdle for first time keto-dieters to overcome as this period of metabolic adaptation can be stressful, met with cravings and hunger, fatigue and extreme irritability.
There’s also a chance of developing what is known as the “keto flu” – flu–like symptoms that occur during the metabolic adaptation stage.2
Misconceptions regarding keto and muscle building
The main reason why people are sceptical about building muscle following a keto diet is due to its effect on insulin production.
Insulin is described as an anabolic hormone (i.e. a hormone associated with “creating or building” rather than breaking down).3
It does this by binding to a cell (such as a muscle cell) and signals to that cell to take in nutrients. Relating back to muscle building, the influx of nutrients can contribute to repair and growth of the muscle (after having been broken down by exercise).
Whilst this may be true, there are other more important pathways to support muscle building. High–protein diets rich in high–quality proteins (either animal sources or complimentary plant sources) will contain plenty of leucine.
Leucine is one of the building blocks of protein (an amino acid) which is most popular for its ability to stimulate muscle protein synthesis.
How would a keto diet support muscle building
As mentioned, keto diets will typically be higher in protein and protein sources, especially leucine rich sources, that can stimulate muscle protein synthesis on their own.4 However, insulin may have an added benefit when it comes to hypertrophy (growth).
One important thing to note though, if met with this argument, is that leucine itself also actually stimulates insulin production.4
So, the necessity for carbohydrate really comes into question then. This isn’t to say it may be optimal for some when it comes to recovery and adaptation, but what it does suggest is that the thought you cannot build muscle on a keto diet appears to be incorrect (which is reflected in a large number of studies supporting ketogenic diets and muscle building).5
Whilst not directly related to muscle building per se, the keto diet may also help you get leaner (which contributes to a more defined muscular look) and retain more muscle mass (especially true when it comes to age related loss of muscle mass or inactivity).5
Notably, as you undergo metabolic adaptation to a ketogenic diet you may experience a decrease in exercise performance (just as you would expect if you were feeling “under the weather”). 6
However even this appears to even out over time (although individual response varies and some people perform better on a low carb diet and some perform better on a high carb diet).7
Muscle may also appear “smaller” or “flat” due to a reduction in glycogen and water, but the actual tangible muscle hasn’t changed.
Take home message
The thought that a keto diet can negatively impact your ability to gain muscle is misleading and shows a lack of understanding as to how muscle building works.
Muscle building is just as achievable following a ketogenic approach as it would be any other and may arguably be greater than others if promoting an increased intake of high-quality protein sources.
Yes, there may be some initial difficulty when transitioning over, but there appears to be no reason as to why you can’t develop a significant amount of muscle following a ketogenic diet.