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Calories and Macronutrients

Updated: Aug 3, 2020

Understand what calories and macronutrients are, how they differ and what they mean.


Before we go into talk about what the difference is between calories and macronutrients, we will first talk about energy. The reason is because both calories and macronutrients provide energy for the body. Energy, in a nutritional sense, refers to the fuel that can be burnt in the body to release energy for the body's functions, whether that be exercise or hormonal production etc. It is the fuel for all bodily functions. So that's basically energy in a nutshell, quite simple to understand. It is just fuel for our bodies to burn so that we can use it to function.


So what provides us with energy? That's where calories come in. A calorie is a unit of energy, it is the unit that is used to measure the energy in food. You may have also heard of the term kilojoule as well. 1 calorie = 4.184 kilojoules, but they basically mean the same thing, they are measurement of the energy within food. Calories in food represent the ability of that food, or potential ability, to provide the body with energy once it is consumed, broken down and absorbed by the body. Calories are found in all foods in different amounts, meaning some foods are more energy dense than other foods. As stated above, energy is received from calories to provide fuel for the body's functions, not just energy for physical activity, but for every single bodily function from growth, repair, hormone production and so on. So basically there are many functions and processes your body goes through that needs energy to work. So calories are just the basic measurement of energy that a certain food provides or potentially provides, but the function that the energy will be used for (whether it be for muscle repair, exercise or hormone production etc) depends on the type of calories we consume.


This is where macronutrients come into play. The three macronutrients are Protein, Carbohydrate and Fat, I'm sure we have heard of them before. Whenever someone mentions the word macronutrients, they are referring to these three. Each macronutrient contains calories (energy) but for different uses of the body, each macronutrients calorie density is different: Carbohydrates contain 4 calories per gram

Proteins contain 4 calories per gram

Fats contain 9 calories per gram


So for each macronutrient, the calories they provide are used differently for the body, this means that the calories of each macronutrient provide a different type of energy for a different bodily process. I will briefly go through each macronutrient and their energy functions (in depth explanations of each macronutrient will be posted on separate blog posts):

Carbohydrates - Provides the main energy sources for body's physical function. The brain, nervous system and muscle tissue depend on carbohydrates for energy to function properly.

Proteins - Provides energy for body to repair muscle and tissues around the body. It is essential component of all cells and tissues in the body. It maintains, grows and repairs the structure of the body.

Fats - Functions as the formation of body structures within cell membranes, provides insulation and protection to body's vital organs and is needed for hormone regulation and production.


Calorie counting

The main point of this blog was for you to understand the difference between calories and macronutrients and what they do for the body. I know many people out there count calories. They count how much calories they should be eating a day, and as long as they meet it, they think all is good. But the more important question is what type of calories are we eating? I'm not saying that counting calories is a bad thing, however, it must not be our only focus. We must also look at what type of calories we are eating, as we now know, each type holds a different function that is needed by the body. This is important because if we meet our calorie goals, but all calories are from carbohydrates, we miss out on the functions that protein and fats provide. So we need to be aware of our macronutrient intake too.


FOR EXAMPLE - this means if our goal is to eat 2000 calories a day, we must also take into consideration how much of those 2000 calories are coming from carbohydrates, proteins and fats. We shouldn't simply eat only rice to get those 2000 calories as it is only giving us limited nutrients and energy functions.


The general rule of thumb is to consume 20%-30% of calories coming from protein, 40%-50% of calories coming from carbohydrates and 25%-35% of calories coming from fats. Now this is not a must follow guide in terms of amount of each macronutrient, this is just a general guide for general population

IF, you are overweight or underweight or training for specific goals (whether it be weight loss, strength, muscle gain, marathon running etc) these numbers will be different. I will cover this in separate blog posts as it is too much info for one post.


To sum up the message of this blog, calories are the units of energy, the general term for energy used by the body for all functions. Macronutrients are different types of calories that provide energy for certain functions of the body. Therefore, we need to place emphasis not only on the calories we consume, but the type of calories also. This is to make sure that our bodies receive what they need to function properly. I hope you all understand the difference between calories and macronutrients and what they do for the body.