How Many Calories in a Gram of Protein?

If you want to achieve your ideal body composition, whether that entails losing weight, gaining weight or maintaining a consistent level of mass, you need to know about calories and how they work.

What many people don't know is that each macronutrient - protein, carbohydrates, and fat - contain a different amount of calories, even if the physical weight of each is the same.

Having a full understanding of the amount of calories in each gram of protein, along with how calories and macronutrients work will be a significant help in your quest to reach your health and fitness goals. That's what we're going to share with you in this article.

Key Takeaways About Calories in a Gram of Protein

  • Protein contains approximately 4 calories per gram, making it a nutrient-dense component of your diet.

  • Digesting protein requires energy expenditure, with around 1-1.5 calories needed to digest 1 gram of protein.

  • Protein has a higher thermic effect than carbohydrates and fats, meaning your body burns more calories breaking down protein.

  • Tracking your macros, including protein, carbohydrates, and fat, can be beneficial for body recomposition, muscle gain, and weight maintenance goals.

  • Accurately reading food labels helps you understand serving sizes, calories, and nutrient composition, which will help you make informed dietary choices.



How Many Calories are in a Gram of Protein?

Each gram of protein contains four calories.

So, for example, if you ate 3 ounces of chicken, that would be around 21-28 grams of protein which is about 100 calories.

However, this is only the amount of calories you get from protein. Chicken breast contains a small amount of fat too, which you need to consider if you're calculating the total calories you're ingesting (for reference, each gram of fat contains nine calories).

Carbs or Protein: Which Has More Calories Per Gram?

Both carbohydrates and protein contain the same amount of calories per gram - four calories.

Fat is the only macronutrient with a different amount, at nine calories per gram.

While carbs and protein have the same calorie density, each has a unique purpose for your body and overall health, and each have their place in a healthy diet.

On one hand, carbohydrates are the body's preferred source of energy and play a vital role in fueling your workouts and daily activities. 

On the other hand, protein is essential for building and repairing tissues, supporting muscle growth, and maintaining a healthy immune system. 

Both carbs and protein (and fat, too) are needed for optimal health and performance.

It's important to find a balance between consuming enough carbs for energy and also incorporating sufficient protein to support your body's repair and growth processes.

Remember, it's about finding the best combination for you and your goals.

How Many Grams of Protein Do I Need?

The amount of protein you need is going to depend on your goals and lifestyle. So, to understand how much protein you should get, start by defining your goals and recognizing what's realistic for where you currently are.

A daily protein intake of 0.8 grams per kilogram of body weight is adequate for general health and overall well-being. This could also be a good starting point if this is the first time you've focused on protein. 

If you are working out or want to improve your performance, you'll want to increase your protein intake. Research suggests that consuming 1.2 to 2.0 grams of protein per kilogram of body weight may benefit athletes (1).

Higher protein intake becomes even more crucial if you want to focus on building lean muscle mass.

Aim for approximately 1.8 to 2.7 grams of protein per kilogram of body weight to support muscle repair and growth (2).

If you have trouble hitting your protein goals, consider a protein shake either before or after a workout to increase daily consumption. 

Chatting with a healthcare professional or a registered dietitian is always a good idea to dial in your protein needs. 

How Many Calories Should I Eat Each Day

The ideal caloric intake depends on various factors, such as your age, sex, weight, activity level, and body composition goals. Plenty of calculators you can use online can help calculate this for you. 

The main thing you need to understand is your calorie output. This is how much energy your body uses each day, for things like normal bodily functions, digestion, daily activities (e.g. walking around, fidgeting), and exercise.

To get a rough idea, the average woman uses 1,600 to 2,200 calories per day, while the average man uses 2,200 to 3,000, per Dietary Guidelines for Americans.

Your ideal calorie intake then depends on whether you want to lose weight, gain weight, or maintain the same weight.

To lose weight, you'll need to be at a caloric deficit, meaning you eat fewer calories than you burn. While to gain weight, you want to be at a caloric surplus, and take in more calories than you put out.

To maintain your current weight, you will want to eat around the same amount of calories as the amount of energy you use daily. 

Your caloric surplus or deficit should be approximately a 10-20% difference. Meaning, if you want to gain weight, it's recommended to take in 10-20% extra calories than the amount you burn (and the inverse for losing weight).

You can achieve results faster by increasing the difference between your calories in and calories out, but doing so can have negative health effect. Too much of a caloric surplus and you'll pack on a lot of excess body fat, and if your caloric deficit is too large you'll feel weak, tired and the body may not have enough energy for normal bodily functions.

Food Labels and Calories

Reading food labels should be learned early on when focusing on nutrition. Marketing can lead to confusion, and it's not unlikely that you eat an entire protein cookie and later realize the little package was four servings. Whoops!

So, be sure to note the serving size before diving in or trying a new product at the store. Reviewing the serving size will help you determine the number of calories you'll consume and consider how it fits into your daily intake goals. 

Remember to consider other key information on the label, such as the macronutrient breakdown (protein, carbohydrates, and fat), as this can help you understand the nutritional composition of the food. 

Being mindful of food labels empowers you to make choices aligned with your health and wellness goals.

Tracking Macros: Protein, Carbohydrates, and Fat

Alright, let's talk about tracking macros, my friend! It's all about keeping an eye on your protein, carbs, and fat intake to achieve different goals.

For Body Recomposition

If you're looking to change your body composition, which usually means reducing fat and building muscle, while maintaining roughly the same body weight, you'll want most of your macros to come from protein and carbs.

High-protein foods will support muscle growth, while carbohydrates will support energy production and ensure you have the energy you need to train. You will also want some fats, though try to avoid unhealthy fats (such as trans fats and saturated fat), opting instead for healthier polyunsaturated fats, such as fish, some vegetable oils, plants and seeds.

Your fat intake will likely make up 15-20% of your total calories for physique-focused individuals and 30% for athletes. 

Once you have that figure, calculate your protein needs from the 1.8-2.7 grams/kg shared above (1)

The remainder of your calories will be from your carbohydrates to recover properly and keep your energy levels high. You may find that you need fewer or more calories - this will take time to figure out what works best.

For Muscle Gain 

If you're on a mission to gain some serious muscle mass, protein becomes your best friend, providing the building blocks for growth, while carbs fuel those intense workouts. The remainder of your calories will be from fats. 

Using the same protocol as above with slightly more calories will be best. Then, you can make adjustments based on how your body responds. 

To Maintain Weight

If you feel like you are at a healthy weight and want to maintain it, you'll benefit from a balanced approach. This could be something as simple as around 20-30% protein, 45-60% carbohydrates, and the remainder from healthy fats.

For Weight Loss

Macros are less important for weight loss than calories. You basically just want to be eating fewer calories than you burn. However, eating a high protein diet can help. The body stores any excess calories from fat and carbs as body fat (to be used as energy in the future). It doesn't store excess protein, though - it's excreted in the urine.

So while you still need a certain level of fats and carbs to support energy production and regular bodily functions, keep your total fat intake and carb intake low, and try to get most of your calories from lean protein.

FAQs About Protein and Calories 

How Many Calories are in 100g of Protein?

In 100g of protein, there are approximately 400 calories. Remember, there are 4 calories per gram of protein.

Remember that this is only the calories in the food from protein - most foods also contain some amount of carbohydrates and fat, which also contribute to the total calories you ingest.

How Many Calories Does it Take to Digest 1 Gram of Protein?

It takes about 1-2 calories to digest 1 gram of protein. This is known as the thermic effect of food, where your body uses energy to break down and process nutrients. 

Does Your Body Burn More Calories Breaking Down Protein?

Protein has a higher thermic effect than carbohydrates and fats, meaning your body burns more calories breaking down protein. The diet-induced thermogenesis is about 20 to 30% for protein - this means when you eat 200 calories of protein, it's only about 140 calories of usable energy (3)!

So, incorporating protein into your meals provides essential building blocks for your body and gives your metabolism a little boost.

Can You Get Enough Protein on a Vegetarian or Vegan Diet?

It is possible to get sufficient protein intake without eating meat. There are plenty of high-protein foods that are vegetarian or vegan, such as lentils, chickpeas, tofu, nuts, seeds, kidney beans, quinoa and oats.

Some vegan protein sources are not whole proteins, however. So you may want to take a vegan protein supplement to ensure you're getting the full range of essential amino acids in your diet.