Limiting Protein Intake While On Keto: A Guide

The keto diet is a low-carb, high-fat diet that has gained popularity for its weight loss and health benefits. However, it's not just about cutting carbs; getting the right amount of protein is crucial, too. So, how much protein is too much on keto?

There's a common misconception that too much protein can kick you out of ketosis – the metabolic state where your body burns fat for energy instead of glucose. This belief stems from the idea that excess protein increases blood sugar and insulin levels through a process called gluconeogenesis, ultimately inhibiting ketone production.

However, this notion has been largely disproven. Gluconeogenesis is a natural and necessary process that occurs regardless of protein intake, ensuring your body gets the glucose it needs to function. In fact, studies suggest that extra protein does not lead to more gluconeogenesis.

That being said, the ideal protein intake on keto can vary from person to person. Generally, it's recommended to consume between 1.2 to 2.0 grams of protein per kilogram of body weight. This range helps preserve muscle mass, improve body composition, and provide other health benefits.

For those looking to maintain muscle mass while losing weight, aiming for a higher protein intake of 1.6 to 3.0 grams per kilogram of body weight may be beneficial. This is especially important for older adults wanting to stay active and healthy, as adequate protein intake can help prevent muscle loss and physical decline associated with ageing.

On the other hand, those with type 2 diabetes or cardiovascular risk factors may need to be cautious with their protein intake, as it can affect blood sugar and insulin levels.

To find your personal protein sweet spot on keto, you can test your limits using a ketone meter. Start by reducing your carb intake to below 20 grams per day for about a week to enter ketosis, and then gradually increase your protein intake until it knocks you out of that state. That number is your upper limit for keto.

Remember, protein is essential for several bodily functions beyond muscle growth and repair, so make sure you're getting enough.

Calculate your keto macros, then increase your protein intake gradually until you reach your upper limit for ketosis

To calculate your keto macros, you can use a keto calculator. This will help you figure out the exact amount of carbs, fat, and protein you need to reach your goal weight. To use a keto calculator, you'll need to input your gender, age, height, weight, and activity level.

Once you've calculated your keto macros, you can start increasing your protein intake gradually. According to ketogenic diet experts Stephen Phinney, MD, PhD, and Jeff Volek, PhD, RD, the ideal way to calculate protein needs for people on keto is in grams per kilogram of body weight. They recommend a target range of 1.2-2.0 g/kg of body weight, depending on your lifestyle. For example, if you are a male who lifts heavy weights often, you may want to eat at the higher end of the protein range, while a smaller female who doesn't do much weight lifting may do better at the lower end.

It's important to note that protein is a goal to reach, not a limit. You should aim for a moderate amount of protein, which is generally 20-30% of your total daily calories. This is equivalent to 1.2-2.0 g/kg of body weight.

As you increase your protein intake, make sure to also increase your fat and carbohydrate intake to match your total daily calorie allowance. You can use the following calculations to determine your macronutrient breakdown:

• Protein = 4 calories per gram
• Carbohydrates = 4 calories per gram
• Fats = 9 calories per gram

For example, if your goal is to eat 150 grams of protein and 30 grams of carbohydrates with a 2,100 daily calorie allowance, your fat intake would be calculated as follows:

150g protein x 4 = 600 calories

30g carbohydrates x 4 = 120 calories

2,100 - (600 + 120) = 1,380 calories

To find your fat intake: 1,380 / 9 = 153g of fat

By gradually increasing your protein intake and adjusting your fat and carbohydrate intake accordingly, you can reach your upper limit for ketosis while ensuring you're getting enough protein to support your health and fitness goals.

Aim for 1.6 g/kg body weight per day as a rule of thumb, but adjust based on individual needs

The ideal amount of protein to consume on a keto diet is a highly contested topic. While some believe that too much protein may be detrimental and could throw you out of ketosis, others argue that too little can hamper recovery, decrease lean muscle mass, and make it harder to lose weight.

As a rule of thumb, it is recommended to consume 1.6 g of protein per kg of body weight per day. This equates to 20-30% of your calories coming from protein. However, it's important to note that this may vary depending on individual needs and certain factors.

For example, people looking to maintain muscle mass while losing weight may benefit from a higher protein intake. Research suggests that diets containing 18%-25% protein can result in greater muscle maintenance when compared to lower protein diets (at 10–12% protein). Additionally, a moderate to high protein intake of 1.2 g/kg of body weight was shown to prevent muscle loss when combined with calorie restriction and resistance training. Furthermore, consuming 2.4 g/kg of protein per day, along with resistance training and a calorie-restricted diet, resulted in an increase in muscle mass over a 4-week period.

Another factor to consider is age. As we get older, maintaining muscle mass becomes increasingly important to prevent sarcopenia, which is associated with a higher risk of falls and fractures. Research suggests that higher protein intakes for older adults (more than 20% of calories from protein) can help maintain muscle mass and physical function.

If you are an athlete or highly active individual, you may also require a higher protein intake. While most sources recommend a protein intake of 1.6 g/kg of body weight for highly active individuals, some suggest that this may be too much. A study in the '80s followed elite bodybuilders who trained 90 minutes a day, 6 days a week, and found that the upper limit of protein intake for optimal body composition was 0.75 g/lb (1.65 g/kg). It's also important to note that this figure would be the upper limit for muscle gains if you are in a caloric balance and not aiming for weight loss.

On the other hand, if you are consuming a caloric deficit and aiming for weight loss, you may benefit from a higher protein intake of 2.4 to 3 g/kg per day. This is because protein helps preserve or build lean muscle mass, and higher protein intake can aid in weight loss by increasing satiety and boosting metabolism.

It's worth noting that there are potential risks associated with consuming too much protein, especially for those with diabetes or prediabetes. While gluconeogenesis—the process by which the body makes glucose from non-carb sources—is essential for maintaining a state of ketosis, it can also lead to a small increase in glucose production. Additionally, too much protein may decrease ketone levels due to its moderate insulin-stimulating effect. Therefore, it's important to monitor your ketone levels and adjust your protein intake accordingly.

If you're in a calorie deficit and aiming for weight loss, a higher protein intake of 2.4 to 3 g/kg per day may be beneficial

• Protein helps you feel fuller for longer, reducing appetite and preventing overeating.
• It has a high thermic effect, meaning your body uses more energy to digest it compared to fats or carbohydrates.
• Protein is essential for building and maintaining muscle mass, which is important for keeping your metabolic rate high and making it easier to lose weight.
• Consuming adequate protein can help prevent muscle loss during weight loss.
• Protein can also help stabilise blood sugar levels when consuming carbohydrates.

To ensure you're getting enough protein while on a keto diet, it's recommended to consume a minimum of 1.2 to 2.0 grams of protein per kilogram of body weight. This range has been shown to preserve muscle mass, improve body composition, and provide other health benefits. However, if your goal is to lose weight while maintaining or building muscle mass, you may want to aim for the higher end of this range or even slightly above it.

It's important to note that simply increasing your protein intake may not be enough to achieve your weight loss goals. A calorie deficit is still necessary, and it's crucial to consider your overall calorie intake and macronutrient distribution. Additionally, when it comes to weight loss, the quality of your food choices matters just as much as the quantity. Focus on choosing high-quality, nutrient-dense foods to ensure you're getting adequate nutrition while staying within your calorie goals.

If you're older, recovering from an injury or illness, or are an athlete, you may need more protein

If you're older, recovering from an injury or illness, or are an athlete, you may need to increase your protein intake. Here are some reasons why and some tips on how to do so:

Older Adults and Protein Intake

The recommended dietary allowance for protein is 0.36 grams per pound of body weight daily. However, older adults may need up to 50% more protein due to age-related changes in the body's ability to utilise protein effectively. Inflammation from infections, chronic diseases, and certain medications can also increase protein requirements.

To maintain and build muscle mass, older adults should aim for 0.45 to 0.55 grams of protein per pound of body weight daily. This amounts to approximately 25 to 30 grams of protein per meal.

It is important to note that the body's ability to utilise protein decreases with age, so simply consuming more protein may not be enough. Spreading protein intake evenly throughout the day and including resistance training in your routine can help maximise muscle protein synthesis and improve overall health.

Recovery from Injury or Illness and Protein Intake

During recovery from injury, illness, or surgery, your body requires additional protein to repair and rebuild tissues. The recommended protein intake during these periods is 1.2 to 2.0 grams per kilogram of body weight, and this may temporarily need to be higher.

Athletes and Protein Intake

Athletes, particularly those engaging in weight lifting and resistance training, typically need more protein than sedentary individuals of the same height and weight. If you are an athlete, a protein intake of up to 1.6 grams per kilogram of body weight may help increase and maintain muscle mass.

To summarise, while the general guidelines for protein intake on a keto diet suggest 20 to 30% of calories from protein, certain individuals may require more. Older adults, those recovering from injuries or illnesses, and athletes should assess their protein needs and adjust their intake accordingly, ensuring they consume adequate amounts of high-quality protein to support their health and fitness goals.

Choose healthy protein sources, such as full-fat dairy, collagen, or whey protein

Dairy products are a great source of protein, but not all dairy is created equal. Full-fat dairy, such as grass-fed butter, heavy cream, cottage cheese, and cream cheese, is a better option for keto dieters than low-fat or skimmed milk, which has a higher carb content. Greek yogurt is also a good choice, as it has fewer carbs and is thicker than other yogurts due to the straining process that removes much of the liquid whey.

When choosing cheese, harder cheeses like Parmesan, Swiss, and cheddar are better options than softer cheeses, as they have fewer carbs and are lower in lactose, which can cause gastrointestinal issues for some people. Semi-hard cheeses like Swiss and Monterey Jack are also keto-friendly. Brie cheese is another good option, with less than a gram of carbs per ounce. Mascarpone and creme fraiche are also good choices, as they add tons of flavor and creaminess for very few carbs.

In addition to dairy, collagen is another excellent source of protein. Collagen is the most abundant protein in the body and is often referred to as the "glue" that holds the body together. It has a wide range of health benefits, including improving skin health, preventing hair loss, maintaining the integrity of tendons and ligaments, strengthening bones, and ensuring optimal brain function.

Whey protein is another option for keto dieters looking to increase their protein intake. Whey is one of the two main proteins found in milk, the other being casein. While casein makes up about 80% of the protein in milk, whey makes up the remaining amount. Whey protein is quickly absorbed by the body and can be an effective way to support muscle growth and recovery.

Frequently asked questions