Keto For Bodybuilding? Can You Actually Build Muscle on Keto Diet?

Much controversy surrounds the keto diet. Some claim it’s the best way to eat for losing fat and shaping an eye-catching figure. Others say it’s just another fad: here today, gone tomorrow. Who’s right?

In this article, you’ll discover the truth on the keto diet for bodybuilders. We take an unbiased look at what current scientific research says, so you can decide whether going keto is right for you.

What Is the Keto Diet?

On the keto diet, you eat high amounts of dietary fat, moderate amounts of protein, and only a tiny bit of carbs.

To maintain this low carb intake, you don’t eat foods like grains, potatoes, legumes, beans, starchy vegetables, most fruits, honey, and other sugary products.

But what you do eat low-carb foods like meat, fish, eggs, nuts, seeds, leafy vegetables, and certain dairy products.

Here’s what a day of keto eating can look like:

  • Breakfast: Poached eggs with spinach and macadamias
  • Lunch: Wild asparagus with minced tuna and garlic
  • Dinner: Pan-seared boneless lamb chops with broccoli
  • Snack: Creamy button mushroom soup

There’s no set-in-stone amount of carbs to eat on the keto diet. That’s because various factors like metabolism, activity level, and body weight influence how many carbs you should strive for each day. Generally speaking, however, you’ll consume fewer than 50 grams of carb a day.

Due to this minimal carb intake, glucose levels in your body drop. This causes the production of “ketone bodies,” an energy source your body can use when glucose is scarce.

When your body mostly uses these ketones and fatty acids for fuel (rather than glucose), you enter a state we call “ketosis.” Keto-diet proponents claim such a state has many benefits, including superior fat loss.

But does the keto diet live up to these often-made claims? In the upcoming two sections, we take an unbiased look at the pros and cons of this eating style when it comes to fat loss and muscle growth.

The Benefits of the Keto Diet for Bodybuilders

What follows are two evidence-based benefits the keto diet may offer bodybuilders. As we’ll see, however, neither is as useful as is often claimed.

(Somewhat relevant) benefit #1: Superior weight loss

The keto diet can be an excellent way to drop the number on your scale. For example, a meta-analysis of thirteen randomized, controlled studies concluded:

“Individuals assigned to a VLCKD [very low carbohydrate ketogenic diet] achieve a greater weight loss than those assigned to an LFD [low-fat diet] in the long term; hence, a VLCKD may be an alternative tool against obesity.”(1)

Plus, other randomized controlled trials show the keto diet can produce up to three times as much weight loss as a high-carb, low-fat diet.(2)(3)

Sounds impressive, doesn’t it? But before we conclude that the keto diet is superior for those who want to lean down, hold on for a second. There are four essential points to make:

First off, most studies that compare the keto diet to a regular eating style for weight loss use overweight and obese participants. This doesn’t necessarily mean the same benefits apply to bodybuilders who want to lean down into single digit body fat percentages.

Second, most studies that show better weight loss results produced under the keto diet don’t match macro intake among subjects. The keto diet is often higher in protein. And because higher-protein diets are better for weight loss, this could be a reason the keto dieters lose more weight.

Third, research shows going keto produces more weight loss, not necessarily more fat loss. And as a physique athlete, it isn’t about how much weight you lose; it’s about how much fat you drop.

Fourth, the primary reason the keto diet causes more weight loss is that it induces water loss. The keto diet reduces fluid levels in two main ways:

  • By lowering insulin levels. This causes your kidneys to excrete sodium from your body, which leads to flushing out water.(4)
  • By reducing liver and muscle glycogen storage. Since each gram of glycogen attracts at least three grams of water, if your glycogen levels would reduce by 400 grams, the number on your scale drop by 1.5 kg or more.(5)

In other words, while the keto diet causes more weight loss, this is of little value for bodybuilders because it’s primarily due to water loss, not fat loss.

(Irrelevant) benefit #2: Increased fat burning

I bet you’ve heard it before, the claim that eating more fat while cutting carbs from your diet turns you into a fat burning machine. But is it true? The answer is yes. If you follow a keto diet, your body will burn more fat for fuel.(6)(7)

And while that may sound beneficial in theory, it’s trivial in real life. Here’s why:

While you burn more fat for fuel on a keto diet, this doesn’t lead to losing more body fat.(8) The reason your body burns more fat is that you eat more fat, not because this eating style has any unique body fat burning abilities.

To illustrate this, compare your body as a fireplace. Whatever macro you dump into it is what will get burned. Take in more carbs and your body will burn more glucose. Take in more dietary fat and your body will burn more fatty acids.

In other words, the claim that the keto diet helps you burn more fat is correct, but it’s misleading and irrelevant because it doesn’t lead to more fat loss.

The Downsides of the Keto Diet for Bodybuilders

The Downsides of the Keto Diet for Bodybuilders

As we’ve just seen, the keto diet can cause more weight loss but doesn’t lead to more fat loss. That’s why the so-claimed weight loss benefits of the keto diet are irrelevant for bodybuilders.

But what are the downsides of this eating style? Could it be that, in certain ways, the keto diet is inferior for building muscle and losing fat? The answer is yes. Here are the five (potential) problems of going keto.

Downside #1: Can impair resistance training performance

While some studies found the keto doesn’t impair athletic performance, most data shows performance worsens if you only eat a tiny bit of carbs.(9)(10)(11)(12)

In particular endurance-type activities such as long-distance running, soccer, basketball, and football are affected. That’s because energy production during these activities relies on glucose, a stored form of energy derived from carbs.

But not only endurance sports are affected. Low-carb dieting can also impair weight lifting performance, as shown by research published in The Journal of Strength and Conditioning Research. (13)

The researchers found that two days of reduced carb intake significantly lowered the amount of squats females could do with 80% of their one rep max.

Downside #2: Worsened muscle growth

Because the keto diet can reduce workout performance, this eating style may lead to inferior muscle growth results.

After all, if you can’t perform at your best in the gym, it’ll be harder to apply progressive overload, which is crucial to building muscle.

What’s more, low muscle glycogen levels post-workout impair signalling related to muscle growth. This may hurt your gains and make you susceptible to muscle loss when you diet.(14)

In other words, if you want to maximize muscle growth, you’ll likely get better results if you add some carbs to your diet.

Downside #3: Increased hunger cravings

Effective fat loss requires you to consume fewer calories than you burn. While it sounds easy in theory to do this, it’s often a struggle in real life because hunger cravings rear their ugly head if you lower your food intake.

The problem with the keto diet, however, is that you get most of your calories from dietary fat – the macro that’s much less satiating than protein and carbs. (15)(16)(17)

That’s why going keto may cause severe hunger cravings, which makes it harder to control your calorie intake.

Combine this with the fact that dietary fat is the most calorie dense macro, and you’ll understand why it’s easier to overeat on a high-fat diet and why obesity is more common among high-fat dieters.(18)(19)

Downside #4: Difficult to adhere to during social gatherings

If you go to a social gathering or restaurant as a keto dieter, you’re faced with a dilemma. Most meals have more carbs than your nutrition plan allows for the day. What to do?

You can eat like the other folks, which takes you out of ketosis. You can skip the food, which makes you a social outcast. Or you can search for a keto-friendly dish, which is sometimes available but not always.

In other words, since most “social foods” and almost all alcoholic drinks contain at least some carbs, it can be hard to adhere to a keto diet during social gatherings.

Downside #5: Can cause nutrient deficiencies

Because you cut carbs from your diet on a keto diet, you won’t be eating fruits, whole grains, legumes, beans, and potatoes – all foods that contain many beneficial nutrients.

Also, consider that some nutrients are hard to get from low-carb foods alone. An example of this is vitamin C. This vitamin is primarily found in carb-rich foods, which is why keto dieters are at an increased risk of being deficient in this nutrient.(20)

Not only can nutritional deficiencies affect health, but they can also affect body composition. That’s because many of these nutrients influence processes related to fat loss and muscle growth, including hormone production and your metabolism.

The Bottom Line on the Keto Diet for Bodybuilding

Can the keto diet be helpful under certain circumstances? For sure! In fact, it would be beneficial for most people to drop their carb intake at least somewhat.

But if you want to optimize your physical appearance, you’d be mistaken to cut carbs from your diet. Doing so can hurt workout performance, impair muscle mass, and toughen fat loss by causing hunger cravings.

Instead, if you want to shape an eye-catching figure, here’s what you want to do:

Here’s what to do Instead

While dieting is a broad topic, below you’ll find the four fundamentals of an effective diet for bodybuilders.

Step 1: Optimize your calorie intake

Whether you want to lose fat or build muscle, your first nutritional step is optimizing your calorie intake.

It’s simple. If you want to build muscle, consume more calories than you burn. And if you want to lose fat, consume fewer calories than you burn.

Various factors influence the exact amount of calories you need to eat for optimal gains, such as your body weight and height. To help you out, we’ve created a robust, step-by-step method to calculate your calorie requirements in this article.

Step 2: Get enough protein

After calories, the second most essential nutrition step is ensuring you consume enough protein. Here’s how to determine your ideal protein intake:

  • To build muscle, get at least 1.6 grams of protein per kilogram of body weight daily (0.73 grams of protein per pound of body weight).(21)
  • To lose fat, get between 1.8 and 2.7 grams of protein per kilogram of body weight a day (0.8 and 1.2 grams of protein per pound of body weight.(22)

Step 3: Set your carb and dietary fat target

Both carbs and dietary fat provide unique benefits, not only for your health but also for your figure.

The primary benefit of carbs for physique athletes is that they aid workout performance. By consuming enough carbs, you’ll perform better in the gym, and therefore you’ll be more effective at stimulating muscle growth.

Dietary fat, on the other hand, plays a part in almost all bodily functions. These include supporting cell growth, insulin health, and hormone production.

Here’s what you want to do:

  • Dietary fat: Get between 15% and 25% of your daily calorie intake from dietary fat.
  • Carbs: Get your remaining calories from carbs.

Step 4: Eat the right foods

With the rise of If It Fits Your Macros (IIFYM), lifters often claim food quality as irrelevant for building muscle and losing fat. But that belief is wrong! Food selection does influence your results for various reasons.

One of these reasons is that vitamin and mineral content varies among foods. And your body needs these nutrients to support functions such as your metabolic rate and hormone production.

That’s why you want to get at least 80% of your calories from nutrient-dense foods such as fruit, vegetables, nuts, whole grains, meat, and fish.

Also, aim to have variety in your diet by consuming a wide range of beneficial foods. Doing so helps ensure you’re consuming enough of each nutrient.

Step 5: Determine your meal frequency

Compared to factors like calorie intake, macro intake, and food selection, meal frequency is much less important. However, optimizing this aspect can support your gains. So here’s what you want to do:

  • To build muscle, consume at least three meals a day. (Four or more may be even better.) Doing so aids protein synthesis (i.e., muscle growth).(23)
  • To lose fat, consume three or four meals a day. This aids muscle maintenance and tends to be ideal or most people to manage hunger levels. (24)(25) However, if you find it easier to control calorie intake on a higher frequency, eating more often is fine, too.

Step 6: Drink enough water

While many lifters overlook hydration, it’s a crucial part of every diet because not consuming enough water hurts fat loss and muscle growth.

For instance, research shows that those who don’t drink water habitually consume, on average, 9% more calories a day than those who do.(26) For an average adult male with a daily energy need of 2,500 calories, that represents around 1,575 extra calories a week.

Besides, being dehydrated also worsens gym performance.(27) It reduces motivation, raises fatigue, alters body temperature control, and makes exercise feel a lot harder, both physically and mentally.(28)

And if you can’t train at your best in the gym, you can’t stimulate your muscles optimally, and thereby don’t make the most gains.

Various factors influence the amount of water you should drink. A few examples are body size, the environment you live in, and activity levels. That’s why there’s no set-in-stone water intake that’s best for all of us.

Instead, aim to have at least five clear urinations a day. That’s five urinations during which your urine looks clear, not five in total! If you accomplish that, you’re well-hydrated. If not, drink more water.

Let us know what you think about the keto diet by commenting below. Got any questions? Let us know and we’ll try to get back to you ASAP.

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