Macronutrients: What Role Do They Play In Your Body

Macronutrients: What Role Do They Play In Your Body

Macronutrients are the nutrients our body needs in large quantities, including protein, carbohydrates and fat. Read on to find out their roles in our bodies, how much we need and where to get them.

Introduction to macronutrients

Macronutrients consist of protein, carbohydrates and fat and are the nutrients our body needs in large quantities, whereas, micronutrients consist of different vitamins and minerals and are also essential but consumed in smaller quantities. 

This blog will take you through each macronutrient, its role in our bodies and how counting and keeping track of your macros can help you reach your health & fitness goals.


What is it?

Protein is a crucial macronutrient with a significant role in sports nutrition and exercise science. It can be found in various parts of the body, including muscles, bones, skin, and hair. Proteins are composed of amino acids, often known as the building blocks of protein. There are 20 amino acids, nine of which are essential, meaning that our bodies cannot produce them, so we need to obtain them from food.

What does it do?

Proteins play a fundamental role in maintaining and regulating body functions, including tissue and organ structure. Here are some of the key roles proteins play in our bodies:

  • Promoting growth and development throughout different stages of life
  • Aiding muscle contraction, recovery, and adaptation due to physical activity or exercise
  • Supporting the formation of joint cartilage, hair, skin, and nails
  • Facilitating the transportation of small molecules within cells and throughout the body
  • Assisting in the construction of various cellular components like hormones, enzymes, and antibodies

How much do you need?

Protein needs vary depending on age, gender, weight, activity level, and fitness goals. Protein requirements are  linked to muscle mass and metabolic demands. Those aiming to build or maintain muscle mass should consume between 1.8 and 2.5 grams of protein per kilogram of body weight daily, accompanied by appropriate strength training. On the other hand, individuals focusing on weight loss should prioritise protein intake to preserve lean body mass, support metabolism, and promote satiety, aiming for 30%-35% of daily calories from protein sources.

Where to get it?

Protein is found in various animal-based and plant-based foods, and it’s recommended to diversify your protein sources. Here is a list of common high-protein foods:

  • Eggs
  • Chicken breast
  • Greek yogurt
  • Turkey Breast
  • Lean beef
  • Cottage Cheese
  • Salmon
  • Legumes
  • Lentils
  • Quinoa
  • Protein supplements such as Orbit Nutrition 100% Grass Feed WHEY protein powder

By including a mix of these sources in your diet, you can ensure you are getting a comprehensive range of amino acids.


What are they?

Carbohydrates are a macronutrient that our bodies turn into glucose to be used as energy to function. They generally will make up the most considerable portion of one’s calorie intake. 

What are they responsible for?

As described above, carbohydrates provide us with energy as well as aid in the following functions:

  • Fibre, which is a source of carbohydrates, aids in digestive health.
  • Some carbohydrates can increase healthy gut bacteria, which is also associated with mood and mental disorders.
  • Carbohydrates are essential for the production of serotonin which is a mood stabiliser
  • Carbohydrates can also help to regulate blood sugar which, if drops too low, can cause difficulty concentrating, confusion and drowsiness.

How much do you need?

The suggested amount is between 35% and 55% of your total energy intake. If we do not consume enough carbohydrates, we may not have enough energy for physical and mental well-being. On the other hand, if we consume too much, the unused carbohydrates are converted to fat, risking an increase in body weight.  

Where to get it?

There are three types of carbohydrates, and these include:

  1. Starches (also known as complex carbohydrates) – legumes, rice, wheat, grains, cereals
  2. Fibre – fruit, vegetables, legumes, nuts, seeds
  3. Sugars – glucose, fructose, lactose, sucrose

Some examples of carbohydrates include:

  • Oats
  • Quinoa
  • Fresh Fruit
  • Sweet potato
  • Potato
  • Fresh Vegetables 
  • Chickpeas 
  • Long Grain Rice
  • Wholemeal Pasta
  • Sprouted Bread


The idea that carbs are bad is one of the most commonly misunderstood facts about the macronutrient. The key is understanding the right carbs to eat, and at the right times (around training times are a good idea), not avoiding them all together! As mentioned above, carbohydrates are made up of fibre, starch and sugar. While fibre and starch are complex carbohydrates, sugar is a simple carb source. 

Complex carbohydrates are the ones that we want to include in our diet. They are higher in fibre and take longer to digest meaning the energy they provide lasts longer and keep us feeling full. Main sources of complex carbs include fruits, vegetables, whole-wheat bread, oats and rice. 


What are they?

Dietary fat is an essential part of our diet. Like many other foods, over-consumed fats can be harmful to your health and increase weight; however, when eaten in correct amounts it can provide us with significant benefits. 

There are four types of dietary fats, each with different health benefits, risks and sources. 

They are:

  • Saturated fats
  • Trans fats
  • Monounsaturated fats
  • Polyunsaturated fats

What do Fats do?

Dietary fat has two main functions: providing your body with energy and supporting cell function. Other functions include:

  • It helps keep skin and hair healthy
  • Insulates the body and protects organs
  • It can also help your body to absorb nutrients
  • It can help support & produce essential hormones

How much do you need?

You should consume 20-35% of your calories from fats. If you consume too little fat, you could risk vitamin deficiencies, inflammation, hair loss, slow wound healing and a low functioning immune system. 

On the other hand, consuming too much fat could result in weight gain, as fats are typically higher in calories than protein and carbohydrates. 

Where to get them from?

Some healthy sources of fat include:

  • Avocados
  • Cheese
  • Eggs (including the yolk)
  • Fatty fish like salmon and sardines
  • Full-fat yoghurt
  • Chia seeds
  • Nuts
  • Grass Fed Butter
  • Olives
  • Coconut Oil


Macronutrients are the nutrients that we need. Understanding their roles in our bodies and how much we need can help guide us to eating a diet that will benefit our lifestyle. For our bodies to function optimally, we must eat a nutritious and diverse diet consisting of carbohydrates, protein, fats and micronutrients.

Key Takeaways

  • Macronutrients(Carbohydrates, protein and fats) are the nutrients we need in large amounts: 
  • We will get most of our energy from carbohydrate sources, followed by protein, then fats
  • Protein, Carbs and Fats have different roles in our bodies and come from different types of foods
  • Counting macros is another option that may benefit you as opposed to counting calories

Want to calculate how many macronutrients you need through the day?

Look at it here