Keto Build Muscle and Burn Fat at the Same Time

By Siim Land

The ultimate goal when it comes to body composition and fitness is to build muscle and burn more fat. For vanity and looking good, surely. But there are other health and longevity benefits to this.

Muscle is actually our biggest organ, as the fascia connect all the dots between our ligaments, creating a tissue that covers our entire body. The advantages to having a lean physique are obvious, as it will increase our metabolism, increase our life span, improve nearly every biomarker and actually sharpens our cognition.

What You Need for Muscle Growth

Building muscle is an anabolic process that needs to be facilitated in some way. There are 4 main conditions that need to be met.

  • An Adequate Stimulus (Train Hard Enough) – Resistance training that makes the muscle fibers contract at near maximum effort signal the body to adapt to the stimulus. If there’s a perceived necessity in your environment to be stronger, then you will eventually get stronger. It’s the first determining factor of muscle hypertrophy.
  • Protein Synthesis (Eat Enough Protein) – Training causes scarring damage to your muscle fibers that needs to be repaired, if you were to recover from the stimulus. Amino acids found in protein are essential building blocks of our organism. They’re used for growing lean tissue, skin, nails, hair – everything.
  • Enough Energy (Be at a Caloric Surplus) – All of this is a costly process and requires heat to be carried out. Muscle growth will occur only if there’s a surplus of energy – when the body has managed to cover its more vital functions.
  • Hormonal Output (Mainly Testosterone and Human Growth Hormone) – Hormones are your body’s signaling mechanisms that send messages to conduct certain processes e. protein synthesis, muscle building, fat burning.

All of those conditions can be met on a well-formulated ketogenic diet, without consuming dietary carbohydrates.

How Does Ketosis Affect Performance?

How are you supposed to build muscle if you can’t train? Well, you won’t. The training stimulus is the most important variable, as it directly signals the body to trigger the other processes as well.

However, ketosis doesn’t negatively affect performance nor do you need carbs to train hard. You only need to have enough willpower to push your body’s comfort zone to experience growth and muscle glycogen to make your muscles fibers contract at near maximum effort.

Can You Build Muscle on a Ketogenic Diet?

But how can you replenish your glycogen if you don’t eat carbs? The answer is that you don’t need carbohydrates to do so.

First of all, you would need to do an absurd amount of volume to deplete your glycogen stores. You wouldn’t be able to move afterwards. Even after depleting endurance workouts, glycogen will be replenished within 24 hours. What’s more, in ketosis your body will use less glycogen overall, as the majority of your energy demands will be covered with ketones and fatty acids.

Secondly, the body can produce its own glycogen through gluconeogenesis, during which the liver will convert amino acids and glycerol (the backbone of triglycerides) into glucose. It’s estimated that about 200 grams of glucose can be manufactured daily by the liver and kidneys from dietary protein and fat intake (1).

Thirdly, protein synthesis can occur without the consumption of carbohydrates (2-4). In fact, leucine, found in abundance in eggs, triggers this independent of the main muscle building pathway mTOR (5).

Keto Fat Burning

Unless you’re training the same muscle groups more than once within 1-2 days, then you don’t need exogenous carbohydrates to replenish your glycogen stores.

When it comes to burning fat, ketones are definitely a superior fuel source. In a fresh 2016 study, keto-adapted ultra-endurance ketogenic athletes managed to burn 2.3 times more fat than the opposing high-carb group during a 3-hour workout (6). What’s more, they also burnt primarily fat even at 70% of max intensity versus only 55%. This means that they spared glycogen more efficiently and prevented muscle breakdown.

Testosterone and HGH aren’t negatively affected by eating a ketogenic diet either. Essential fatty acids have a much greater impact on hormones than carbohydrates do. In fact, one of the best T boosting foods are high in omega-3s, saturated fat and cholesterol, such as eggs, fish and beef.

Build Muscle Burn Fat

So, how the keto diet can build muscle and burn fat at the same time? The seemingly impossible task.

Well, it can’t happen simultaneously in the exact moment in time. That’s physiologically out of the question, as the anabolic cycle consists of 2 stages – breaking down and building up.

However, the ketogenic diet can stimulate your body to add more lean tissue with close to zero fat gain and while running on a fat burning metabolism.

How? The biggest determining factor for muscle hypertrophy is inarguably the training stimulus. Simply eating carbs won’t trigger protein synthesis if there isn’t a necessity for adaptation in the body’s perceived environment.

Protein synthesis and surplus energy are easily met, as you don’t need insulin or mTOR to cause muscle growth. They may have augmenting effects but: “Carbohydrates, nonessential amino acids, and other essential amino acids do not have stimulatory effects on protein synthesis when compared with leucine (5).”


Another recent study compared a keto group with individuals who consumed a standard diet. The results showed that the low carb one had significantly higher increases in lean body mass and strength gains (7). On top of that, their fat composition had decreased.

The Keto Diet as Life-Long Training

Even though it’s possible to build muscle on a ketogenic diet, why should we do it? Would it have greater advantages over a high carb approach? Whatever the case might be, maximizing muscle hypertrophy isn’t the purpose of doing keto.

Being constantly anabolic has its downside. Insulin, IGF-1 and mTOR are like double-edged swords. They’re stimulate tissue augmentation in an all-encompassing way, by growing the good (muscle), the bad (fat) and the ugly (tumors). We don’t want to have constantly high levels of these hormones, as they’re correlated with aging and cancer. On keto, you’ll control the expression of them to a great degree.

By the same token, building muscle and doing resistance training on a ketogenic diet is the leanest way of building muscle while burning fat and increasing your longevity at the same time. It’s probably the healthiest way of doing so, while circumventing most of the negative side-effects of anabolism.

To learn more about how to build pure lean muscle and burn fat at an exponential rate, almost at the same time, check out my book called Metabolic Autophagy: Practice Intermittent Fasting and Resistance Training to Build Muscle and Promote Longevity (Metabolic Autophagy Diet)