Keto's Muscle-Preserving Benefits: Fact Or Fiction?

The ketogenic diet is a very low-carb, high-fat diet that has been linked to various health benefits, including weight loss, aiding people with epilepsy, and controlling blood sugar levels. However, there is a common misconception that the keto diet makes it difficult, if not impossible, to build muscle. This is mainly due to the idea that low-carb diets restrict carbs, which promote the release of insulin, an anabolic hormone that helps create conditions that drive muscle growth.

Despite this, studies have shown that it is possible to build muscle on the keto diet. For example, a study in 25 college-aged men found that a keto diet was as effective as a traditional Western diet for muscle gain, strength, and performance. Other studies have also shown that keto may provide similar strength and performance gains as a conventional high-carb diet while helping to shed body fat.

Additionally, the keto diet has been shown to preserve muscle mass during training, dispelling the myth that keto causes muscle loss. For instance, a study involving elite gymnasts found that after adopting a ketogenic diet, muscle mass remained the same, but body fat and body fat percentage decreased significantly.

Furthermore, research suggests that the ketogenic diet can prevent muscle breakdown. Specifically, the ketone body beta-hydroxybutyrate (BHB), produced in higher quantities by keto-adapted individuals, has been shown to decrease leucine oxidation and promote protein synthesis, leading to enhanced protein synthesis and muscle maintenance.

While building muscle on a keto diet is possible, it is important to note that a well-structured diet and proper training are crucial. This includes determining your calorie intake, eating adequate protein, tracking your carb intake, increasing your fat intake, and incorporating resistance training into your routine.

Ketosis can spare protein for muscle maintenance

Additionally, ketosis may affect protein synthesis and breakdown. Some evidence suggests that ketones are directly anti-catabolic, promoting muscle protein synthesis and preventing inflammation-driven catabolic pathways. With the brain's decreased glucose requirements, less protein is broken down as less is needed for gluconeogenesis. Ketosis may also directly spare muscle by decreasing thyroid levels, specifically the thyroid hormone T3, which reduces protein synthesis and lowers the requirement for muscle catabolism.

However, there is also research indicating that ketosis may induce skeletal muscle atrophy in mice by reducing muscle protein synthesis and possibly activating proteolysis. This may be due to hypercorticosteronemia, hypoinsulinemia, reduced insulin-like growth factor 1 (IGF-1), and oxidative stress. Therefore, while ketosis can spare protein for muscle maintenance, more research is needed to fully understand its effects.

Ketones can increase muscle protein synthesis

Firstly, ketones can increase muscle protein synthesis by acting as an alternative fuel source for peripheral tissues such as the brain, heart, and skeletal muscle. Ketone bodies are oxidised as a fuel source during exercise and are markedly elevated during the post-exercise recovery period. The ability to utilise ketone bodies is higher in exercise-trained skeletal muscle.

Secondly, ketone bodies can increase muscle protein synthesis by altering fuel selection through attenuating glucose utilisation in peripheral tissues, anti-lipolytic effects on adipose tissue, and attenuation of proteolysis in skeletal muscle.

Thirdly, ketone bodies can act as signalling metabolites, with β-hydroxybutyrate (βHB) acting as an inhibitor of histone deacetylases, an important regulator of the adaptive response to exercise in skeletal muscle.

Finally, ketone bodies can increase muscle protein synthesis by acting as a protein-sparing agent. Ketosis might improve our ability to utilise proteins. This could be due to the fact that the body no longer needs to break down protein for gluconeogenesis, instead utilising ketones and sparing the protein we have.

In summary, ketone bodies can increase muscle protein synthesis by acting as an alternative fuel source, altering fuel selection, acting as signalling metabolites, and acting as a protein-sparing agent.

A keto diet can help preserve muscle mass during training

The ketogenic, or keto, diet is a very low-carb, high-fat diet that has been linked to various health benefits, including weight loss, aiding people with epilepsy, controlling blood sugar levels, and reducing the risk of various chronic conditions.

It is a common misconception that the keto diet makes it hard, if not impossible, to gain muscle. However, studies have shown that it is possible to build and preserve muscle mass while adhering to a strict ketogenic diet.

Ketosis, the metabolic state that occurs when the body has limited access to glucose or carbs, can improve the body's ability to utilize proteins. This is because, during ketosis, the body no longer needs to break down proteins for gluconeogenesis (the process of creating glucose from non-carbohydrate sources). Instead, it utilizes ketones, which are produced by the liver when the rate of fatty acid mobilization from fat tissue is accelerated.

Ketone bodies flow from the liver to extra-hepatic tissues such as the brain and muscle, where they are used as fuel. This process, known as ketone body metabolism, displaces glucose utilization in the brain, thereby sparing muscle mass.

Additionally, the ketone body beta-hydroxybutyrate (BHB) has been shown to decrease leucine oxidation and promote protein synthesis, further contributing to muscle preservation.

Tips for building muscle on a keto diet

• Determine your calorie intake: To build muscle, you need to consistently eat more calories than you burn. Calculate your maintenance calories (the number of calories needed to stay at the same weight) and increase your intake by about 15% above that amount.
• Eat plenty of protein: Protein is essential for building muscle, as it is the building block of muscles. Most studies suggest that eating 0.7-0.9 grams of protein per pound of body weight is ideal.
• Track your carb intake: To stay in ketosis, restrict your carb intake to less than 50 grams per day. You may benefit from timing your carb intake around your workouts, especially if you feel your performance is affected.
• Increase your fat intake: After accounting for protein and carbs, fat should make up the rest of your diet. Calculate your daily fat requirements by subtracting your protein and carb needs from your total calorie intake and dividing the remaining number by 9.
• Resistance train regularly: Resistance training, such as lifting weights, is crucial for building muscle. Aim for at least twice a week.
• Consider supplements: While not required, supplements like protein powder and creatine monohydrate can help you reach your daily protein needs and improve gym performance.

The keto diet can be an effective tool for building and preserving muscle mass, especially when combined with resistance training. By understanding how the body utilizes ketones and proteins during ketosis, individuals can structure their keto diet to support their muscle-building goals while still reaping the health benefits of this low-carb, high-fat diet.

A keto diet can help athletes maintain muscle glycogen levels

A keto diet is a high-fat, moderate-protein, and very-low-carbohydrate diet. It was initially used as a medical, nutritional therapy to control epilepsy, but it has since been used to reduce weight and body-fat percentage.

A keto diet causes a reduction in fat-free mass and lipid synthesis and increases lipolysis and fat metabolism. Insulin stores glucose in muscle or fat cells and prevents fat metabolism. Being on ketosis leads to low insulin levels and promotes fat oxidation by allowing fats to move from the cell to the circulation. This process of breaking down fats to provide energy leads to a state called ketosis, which happens in 3–4 days.

Athletes predominantly use carbohydrates as their source of fuel. Muscle glycogen and intramuscular glycogen are the major fuel sources used during high-intensity, short-duration activity. However, the human body can metabolically shift and efficiently utilise fat as an energy source during low-intensity, long-duration activity.

A keto diet helps athletes preserve glycogen stores from depleting during exercise. It also stimulates the release, transport, uptake, and utilization of fat in the muscle to convert as energy. However, it takes 3–5 weeks to adapt to the diet, and there might be a possibility of having keto flu.

Weight Loss and Muscle Mass

A keto diet has been shown to reduce weight, and this was observed along with a 10% calorie restriction. It has also been shown to maintain muscle mass as it reduces gluconeogenesis during ketosis and preserves muscle mass, causing a muscle-sparing effect. There is still no positive observation in terms of gaining muscle mass.

A keto diet can help athletes improve performance

Increased fat burning capacity

When on a keto diet, the body switches from using carbohydrates as its main energy source to using fats. This metabolic state, known as ketosis, can lead to a greater ability to utilise fat from food and body storage areas as fuel. As a result, athletes on a keto diet may experience improved body composition, with a reduction in body fat and an increase in lean muscle mass.

Enhanced muscle protein synthesis

The ketogenic diet has been shown to prevent muscle breakdown and improve muscle protein synthesis. This is due to the body no longer needing to break down protein for gluconeogenesis (the process of creating glucose from non-carbohydrate sources) and instead utilising ketones, which are byproducts of fat breakdown. Additionally, ketones have been found to stimulate muscle protein synthesis and reduce the breakdown of branched-chain amino acids (BCAAs), which are essential for muscle growth and maintenance.

Other benefits

The keto diet has also been found to reduce body fat, type 2 diabetes, and metabolic syndrome. It may also improve overall health by reducing insulin resistance, which is a key driver of many chronic diseases. Furthermore, keto diets can lead to a more consistent energy supply, reducing the need for in-race fuelling by over 50%.

However, it is important to note that the effects of a keto diet on athletic performance may vary depending on the type of sport and the individual athlete's genetics and training protocol. Additionally, there may be an adaptation period of several months during which athletic performance could be negatively impacted. Therefore, it is recommended to work with a nutritionist or dietitian experienced with keto diets to ensure optimal results.

Frequently asked questions