Energy Balance and calories for muscle growth

Energy balance and calories sound like difficult concepts, and it’s due to the fact that they are split into other things like macronutrients and vitamins, and minerals. Take a look at the diagram below to understand the concepts better. 

As you can see, calories are at the very top. These calories come from, and each food can be categories into either proteins, carbohydrates (carbs) or fats. It’s fair to say that everything you consume will have a combination between each macronutrients. However, it will be categorised as one or the other simply because it will contain more of one than another. 

During digestion, these macronutrients are broken down to release a variety of vitamins and minerals.  Each nutrient performs a different role in the body, and supports a different process or chemical reaction. Every area in the body needs a constant supply of nutrients in order to function properly.

Calories and energy balance (1)

The importance of calories and energy balance for muscle

Energy balance refers to the calories-in vs calories-out equation. If you consume the same number of calories as you expend, then you will achieve energy balance. This is also known as the maintenance calories.

If you consistently remain in energy balance, your weight will stay the same. There is a possibility that it may fluctuate due to hormonal changes and water retention, but it will roughly stay the same.

So, if you are looking to build muscle, you need to consume more calories than you expend. This is also known as a positive energy balance or caloric surplus. If you consistently consume more calories than you expend, your body will start storing these calories instead of utilising them. 

This is important for muscle growth because if you don’t consume enough calories, your muscles will struggle to grow and you are likely just to build a lean physique. 


If you eat too many calories and do NOT exercise regularly, these calories will be stored in the body as fat. You need to exercise regularly and lift weights in order to encourage the body to store these calories in a form of muscle mass instead. 

Another thing to also note is that when you eat more calories than your body needs, you will always gain a mixture of body fat and muscle. Depending on how regularly you exercise, will determine how much muscle you grow in comparison to fat mass. 

How many calories should you consume?

There are many different equations to calculate your calories, some are simple and some are difficult.  Average people who are looking to build muscle should simply multiply their weight (in KG) by 40. Scientists specified that this is quite accurate for average persons [1].

However, if you feel that this may be a little too simple, you can double check your results with the following equation. Make sure to follow the correct one as they differ between genders. 

Step 1 - Calculate your BMR

BMR stands for Basal Metabolic Rate. BMR is the number of calories your body is able to burn at rest. To calculate your BMR, you need to have your weight in kilograms and height in centimeters.


(0 x weight in KG) + (6.25 x height in cm) – (5 X AGE IN YEARS) – 161 = BMR


(10 x weight in KG) + (6.25 x height in cm) – (5 X AGE IN YEARS) + 5 = BMR

Step 2 - Workout your TDEE

Your ‘TDEE’ is your total daily energy expenditure. That’s the number of calories your body needs daily to perform all the biological and physiological processes as well as any physical activity. This is also known as the maintenance calories. To calculate how many calories your body needs per day, you simply need to multiply the BMR that you calculated in the first step by your activity factor

Sedentary Lifestyle


Moderately active


Highly active


Your BMR x Activity Level =TDEE

There are no specific guidelines to determine which activity factor most suits you. Simply take a holistic view of your lifestyle and consider whether you are more sedentary, moderately, or highly active.

If your goal is to keep healthy and maintain weight then you should consume these calories.

Step 3 - Calculate your calorie surplus

In the previous steps, you learned how to calculate your maintenance calories. In this step, you’ll learn how to calculate your calorie surplus. In order to start building muscle, you must add a number of calories to your maintenance calories. 

Depending on how much weight you wish to gain will determine how many calories you should add. However, one thing to be cautious about is that if you add too many calories, the excess can be stored in the body as fat. Therefore, it’s recommended that you aim for 1-1.2lbs weight gain per week. This is considered to be safe and less risky. 

Below, you’ll find a table that shows exactly how many calories you should add based on your weight goals per week

caloric surplus