The ketogenic diet, often called the keto diet, has garnered significant attention in the bodybuilding and fitness communities. While it may seem like a recent trend, the keto diet has been around since the 1920s. It's a dietary approach characterized by a drastic reduction in carbohydrate intake and a significant increase in fat consumption. This shift in macronutrient ratios forces the body to transition into a metabolic state called ketosis, where it primarily burns fat for fuel instead of glucose derived from carbohydrates. This article explores the potential benefits and risks of using a keto diet for bodybuilding, drawing upon scientific research and expert opinions.
What is the Keto Diet?
The keto diet involves cutting carbs and eating more fat. It's similar to the Atkins diet from the 1970s. Specifically, the keto diet typically consists of:
- 5% of calories from carbohydrates, including low-carb, non-starchy vegetables and small amounts of leafy greens.
- 15% of calories from protein.
- 70-75% of calories from fats.
This translates to a daily carb intake of less than 50 grams, excluding carb-rich foods like grains, beans, fruits, and starchy vegetables.
Roshini G. Merneedi, RD, a dietitian at Northwestern Medicine, explains that your body's primary energy source is glucose, which comes from the breakdown of carbohydrates. The keto diet limits carbohydrates, forcing your body to burn fat for fuel instead. When these stores are full, they are converted into fat. In this state, your body breaks down fats into molecules called ketones. Ketones serve as an alternative fuel source.
Potential Benefits of Keto for Bodybuilding
Fat Loss and Lean Physique
One of the primary reasons bodybuilders consider the keto diet is its potential for fat loss. By drastically reducing carb intake, the body switches to burning fat for energy, potentially leading to a leaner physique. The keto diet allows many people to eat the types of high-fat foods that they enjoy, such as red meats, fatty fish, nuts, cheese and butter, while still losing weight.
Read also: Easy Low-Carb Cheese Crackers
Muscle Preservation
When implemented correctly, the keto diet can help preserve muscle mass during a cutting phase. Consuming adequate protein is crucial for maintaining muscle tissue while restricting calories.
Potential Therapeutic Applications
There is evidence that the keto diet can help specific groups of people. The keto diet helps reduce seizures in children with epilepsy. Endurance athletes and body builders also use it to scrap fat in short timeframes. The keto diet is being studied for reducing symptoms for patients with progressive neurological disorders like Parkinson’s disease. But scientific research has not confirmed benefits for these patients, Dr. Ring says, and more research is needed before it can be widely recommended.
Appetite Control
Some individuals report feeling less hungry on a keto diet compared to other restricted diets. The high-fat content of the diet can promote satiety, helping to control calorie intake and support weight loss efforts.
Potential Risks and Drawbacks of Keto for Bodybuilding
Difficulty in Adherence
Because of the stringent food restrictions, many find the keto diet hard to stick to. “The ketogenic diet can be effective for weight loss when used in a short time period followed by the adoption of healthier eating habits,” says Baljash Singh Cheema, MD, a cardiologist at Northwestern Medicine Bluhm Cardiovascular Institute. “However, we know in studies of these types of diets that once people stop following that diet, they regain at least half of the weight that they lost. Ketosis is difficult to achieve because it’s like a light switch: either on or off. Individuals who consistently track food intake are more likely to remain in ketosis.
Nutrient Deficiencies
“Because the keto diet is so restricted, you’re not receiving the nutrients - vitamins, minerals, fibers - that you get from fresh fruits, legumes, vegetables and whole grains,” says Dr. Ring. People report feeling foggy, irritable, nauseous and tired. “In particular, low fiber intake can disrupt gut microbiota and lead to chronic constipation, while inadequate magnesium, vitamin C and potassium can contribute to muscle cramps, fatigue and weakened immune function,” explains Dr.
Read also: Keto Calorie Counting: A Detailed Guide
Potential Negative Impacts on Heart Health
The high-fat nature of the diet could also have negative impacts on heart health. The American Heart Association recommends limiting saturated fat intake to less than 6%. “In practice, many people eat high amounts of saturated fats, which could increase your risk of heart disease,” says Dr. Cheema. “You may be eating a lot of fatty meat thinking it’s a good thing for you because it's high in fat. This can dramatically alter your lipid profile. While high-fat diets can elevate LDL (“bad”) cholesterol, the type of saturated fat matters. The bottom line is that having more fats in your diet can lead to higher cholesterol. “We know that higher cholesterol tends to increase your chances of heart attacks and strokes,” says Dr. Cheema.
Kidney Issues
The keto diet may not be appropriate for everyone, specifically people with kidney disease. “Although more research is needed in that area, there is some suggestion that it can make kidney disease worse over time,” says Dr. Some people also experience dehydration on the keto diet because they’re eliminating glycogen, which holds water, from the bloodstream.
Psychological Distress
When you micromanage your food intake by tracking how much you eat, it disconnects you from what your body is asking for. You start using outside numbers to determine what to eat instead of listening to your body. “Being intuitive and understanding what your body needs is essential for proper nourishment,” says Merneedi. Monitoring food so closely can lead to psychological distress, such as shame and binge eating.
Blood Pressure and Blood Sugar Drops
The keto diet can cause your blood pressure to drop in the short term due to a reduction in blood volume and changes in your fluid balance. Symptoms of low blood pressure include dizziness, lightheadedness or fainting, especially when standing up quickly. Following a keto diet can also cause your blood sugar to drop, which can be dangerous for people living with diabetes. Common symptoms of low blood sugar include weakness or shaking, sweating, a fast heartbeat and dizziness.
Keto Flu
Also, when people start a keto diet, they go through what's called the keto flu. Keto flu is a set of symptoms that appear 2-7 days after starting the diet. Symptoms include headaches, fatigue, foggy brain, constipation and difficulty sleeping. The body basically goes from relying on sugar to eliminating sugar. That means losing 3-5kg (6.5-11 lbs.) from shedding glycogen molecules that were used to store sugar. As glycogen is kept in cells with a lot of water, your body may get dehydrated and you will feel tired.
Read also: Magnesium Supplements for Keto
Bone Health
There can be issues with bone health when people switch to low carbohydrate ketogenic diets. We see that markers for bone breakdown are higher and markers for bone building are lower. This is a common side effect in kids who are fed a ketogenic diet to treat epilepsy.
Keto vs Carnivore vs Paleo: What Are The Differences?
Choosing the right diet is crucial for building muscle and burning fat. Keto, Carnivore, and Paleo diets are popular options. Each one has its unique approach to improving body composition and boosting performance. Let's dive into how these diets work and which might be best for your bodybuilding goals.
The Keto diet focuses on high fat, moderate protein, and low carbs. This combo aims to put your body into a metabolic state called ketosis. Here, your body burns fat for fuel instead of carbs, helping you stay lean while gaining muscle.
Carnivore diet is all about meat. You eat animal products only, cutting out carbs and plant-based foods. This diet can increase your protein intake, which is key for muscle growth.
Paleo diet takes you back to the basics, eating as our ancestors did. It's all about natural foods like meats, veggies, and fruits, avoiding processed foods and sugars. While it's not low-carb by design, it often ends up being lower in carbs than a standard diet.
Each of these diets has its benefits for bodybuilding. Keto can help you burn fat while maintaining muscle, Carnivore may boost your protein intake significantly, and Paleo focuses on overall health and lean muscle growth. The key is to choose the one that fits your lifestyle, goals, and dietary preferences.
Building Muscle on Keto: Key Considerations
Calorie Intake
To optimally build muscle, you need to consistently eat more calories than you burn. The number of calories you need to eat per day to build muscle depends on several factors, such as your weight, height, lifestyle, sex, and activity levels.
The first thing you need to do is determine your maintenance calories - the number of calories you need to consume per day to stay the same weight. To do so, weigh yourself at last three times per week and record your food intake over the week with a calorie tracking app. If your weight stays the same, that is roughly your maintenance calories. Alternatively, you can determine your maintenance calories using the calculator here.
When you’re trying to build muscle, it’s recommended to increase your calorie intake by 15% above your maintenance calories. So if your maintenance calories are 2,000 per day, you should eat 2,300 calories per day to build muscle. As you build muscle, it’s a good idea to adjust your calorie intake around once per month to account for the changes in your weight. What’s more, it’s recommended to gain no more than 0.25-0.5% of your body weight per week to prevent accumulating too much fat.
Protein Intake
That’s because protein is the building block of muscles, which means that you need to consume more protein than your body breaks down through natural processes when trying to build muscle (20). Most studies suggest that eating 0.7-0.9 grams of protein per pound of body weight (1.6-2.0 grams per kg) is ideal for building muscle (21, 22).
There’s some concern among keto dieters about consuming too much protein because it could encourage your body to use gluconeogenesis - a process in which amino acids are converted from protein into sugar, which could stop your body from making ketones (23).
However, studies have shown that people can safely consume around 1 gram of protein per pound of body weight (2.1 grams per kg) and stay in ketosis (13, 24, 25).
Carb Intake
Traditionally, carbs make up the bulk of the calories on a muscle-building diet. However, if you’re trying to stay in ketosis, then you need to restrict carbs. To reach and stay in ketosis, most people need to eat fewer than 50 grams of carbs per day, although the exact value can vary (3, 26). You may find that timing your carb intake around your workouts can be beneficial, especially if you believe your performance is affected.
This strategy is known as a targeted keto diet, in which you consume your daily allowed carbs around your workouts to aid exercise performance (27).
If you’re struggling to complete workouts, you could try a targeted keto approach. Otherwise, feel free to consume your carbs whenever it suits you best.
Fat Intake
Monitoring your fat intake is incredibly important on the keto diet.
That’s because your body relies primarily on fat for fuel when you limit carb intake and are in a state of ketosis (28).
After accounting for protein and carbs, fat should make up the rest of your diet.
Both protein and carbs provide 4 calories per gram while fat provides 9 per gram. After subtracting your protein and carb needs from your daily calorie needs (see above), divide the final number by 9 to determine your daily fat requirements.
For example, a 155-pound (70-kg) person on a 2,300-calorie muscle gain diet may eat 110 grams of protein and 50 grams of carbs. The remaining 1,660 calories can be taken up by 185 grams of fat.
These guidelines tend to align with standard keto recommendations for fat intake - 70-75% of your daily calories (29, 30).
Resistance Training
While nutrition is important, resistance training is also key to gaining muscle.
Resistance training typically involves lifting weights or doing other strength-based exercises to build strength and gain muscle mass (31, 32).
According to a review of 10 studies, resistance training at least twice a week was more effective at promoting muscle growth than training once per week (33).
Try incorporating exercises like squats, bench presses, pullups, and pushups into your weekly resistance training routine to encourage muscle growth.
If you’re new to the gym, consider hiring a personal trainer to show you proper techniques to maximize your efforts and reduce your risk of injury.
Supplements
While not required, supplements may help you build muscle. If you’re struggling to reach your daily protein needs, you could use a protein powder supplement, such as whey, casein, pea, or hemp protein.
However, it’s important to note that many protein powders contain carbs, so you’ll need to account for these carbs in your daily carb allowance to stay in ketosis. You could also try using a creatine monohydrate supplement, as studies show that it can aid gym performance, leading to more muscle gain (34, 35, 36).
Remember that your body’s levels of sodium, potassium, and magnesium may drop while on keto. Thus, it’s best to eat foods rich in these minerals, such as dark leafy greens, nuts, seeds, and avocados. Alternatively, you can take a supplement.
Expert Opinions and Research Findings
UC Davis Health Study
A new UC Davis Health study found that a ketogenic (keto) diet improves muscle function in older animals by preventing muscle mass loss due to age (sarcopenia). A ketogenic or keto diet includes eating high-fat, low-carbohydrate foods to reach a state of ketosis. A keto diet prevents muscle deterioration and even restores muscle function”-UC Davis molecular exercise physiologist Keith Baar.
Professor Keith Baar, Department of Neurobiology, Physiology and Behavior
It is important that people considering a keto diet to get a blood test and look at their lipids before they switch their diet. They need to take another one after three to six months on the keto diet. Most people will actually find that their high-density lipoproteins (HDL) - that's the good cholesterol - go up and their triglycerides will go down.
The issue with athletes is that you can only compete as fast as you can make energy from fat or sugar. When you only consume fat, your muscles adapt to using it as a fuel. That's totally fine when you're at rest. But when you try to sprint, your body needs to produce energy faster and more efficiently. The ketogenic diet therefore slows the maximal rate of energy production. If you're an athlete, that's the curse of the whole process. When an athlete goes for endurance sports, they’re still better off using carbohydrates.
Contradictory Research
Reviews focused on the ketogenic diet (KD) based on the increase in fat-free mass (FFM) have been carried out with pathological populations or, failing that, without population differentiation. The aim of this review and meta-analysis was to verify whether a ketogenic diet without programmed energy restriction generates increases in fat-free mass (FFM) in resistance-trained participants.
We found no significant differences between groups in the FFM variables, and more research is needed to perform studies with similar ketogenic diets and control diet interventions.
Practical Tips for Bodybuilding on Keto
Meal Planning and Timing
Careful meal planning is essential for success on a keto diet for bodybuilding. Focus on consuming adequate protein and healthy fats while staying within your carb limits. Consider timing your carb intake around workouts to optimize energy levels and performance.
Sample Meal Plan
Here's a sample 7-day meal plan to illustrate how you might structure your diet: