What are Macronutrients, Exactly?

There are a lot of misconceptions when it comes to basic nutrition information that gets perpetuated throughout the media. Because of this, it is important to be able to separate fact from misinformation. In this blog post, we are going to look at a basic nutrition concept: macronutrients. Macronutrients are nutrients which are needed in the largest quantity by our body. These nutrients include carbohydrates, fat and protein.


Perhaps when you hear the word carbohydrate you immediately think, “carbs are bad” or, “if I eat that pasta/pizza/etc., I will gain weight”. There are actually three different types of carbohydrates which are found in many different foods. There are sugars (found in fruit, honey and milk), starches (found in grains), and dietary fiber (found in whole grains, fruits, vegetables, nuts and seeds)1. Carbohydrates are vitally important to the body’s normal functioning as they are readily broken down into glucose which is used as energy for many bodily processes. Every cell in our bodies needs glucose for energy. If we do not consume enough carbohydrates, the body will break down fat and protein to use for energy. This, however, is not preferable because it decreases the amount of fat and protein that can be used for their primary intended functions. If protein is being broken down into glucose, less will be available for use by the muscle and the muscle will begin to be used for energy1. The brain uses only glucose for energy but cannot store it so it needs a steady supply of glucose throughout the day. This is why eating regularly throughout the day is so important.

Carbohydrates have many other important functions including:

  • Specific types promote the growth of beneficial intestinal bacteria
  • Aiding in water absorption which improves hydration
  • Regulating the release of serotonin which controls mood, appetite and sleep/wake cycle1

Carbohydrates are needed in the largest quantity of all the macronutrients. It is recommended that one consumes around 45-65% of their daily energy intake from carbohydrates2.


Fat used to be the macronutrient with the worst reputation, however this misconception was turned on it’s head in recent times. Regardless, many people still think if you eat a food containing fat you will gain fat. This, however, could not be farther from the truth. The body relies on dietary sources of fat for many important bodily functions. These include:

  • Carrying fat-soluble vitamins around the body – that is, vitamins A, D, E and K. It is essential to have some fat in your diet in order to absorb fat-soluble vitamins. These vitamins will not be absorbed by the body or perform their important functions, such as vitamin D for bone strength, vitamin A for sight, vitamin E for its antioxidant properties and vitamin K for blood clotting, among other functions, without the presence of fat3
  • Containing essential fatty acids that our body does not produce
  • Being stored for energy
  • Insulating internal organs
  • Producing hormones used in digestion
  • Health of reproductive system and menstrual regularity
  • Promoting the feeling of fullness after a meal4

Sources of fat in ones diet may include oils, butter, margarine, avocadoes, nuts, seafood, meat, poultry and dairy products. It is recommended to consume at least 2-3 servings of fat per day (1 tablespoon butter, ¼ of an avocado)5, making up around 20-35% of total energy intake2.


Protein is found in all cells throughout your body. Not only is protein found in your muscles, it also makes up hormones, enzymes and your very DNA. Protein helps to build muscle, skin, nails, hair and tissue6. Protein is composed of amino acids which are divided into two groups: essential and non-essential. Non-essential amino acids can be made by the body, whereas essential amino acids cannot be made by the body and therefore need to be consumed through food. Protein is found in meat, poultry, fish, eggs, dairy, tofu, legumes, nuts, seeds and grains. Animal products contain all of the essential amino acids while plant based protein sources only contain some. This is why if you are eating a plant-based diet it is important to combine protein containing foods to ensure you are getting all of the essential amino acids. An example of this is combining bread with peanut butter or beans with rice.

It is recommended that 10-35% of your total energy intake comes from protein, about 0.8-1.0 g per kg of body weight2.

While your body needs all of these macronutrients to survive, it is important to realize that your body takes care of all these complex functions without your knowing it so you do not have to stress about eating a perfectly balanced diet to make sure you have enough of each. Eating a variety of foods in moderation is the best way to ensure you are getting enough of each nutrient!


  1. Carbohydrates Myths and Facts. (2018). Retrieved from http://www.cci.health.wa.gov.au/docs/Carbohydrates – Myths & Facts 15-02-18.pdf
  2. Dietary Reference Intakes: Macronutrients. (n.d.). Retrieved from http://nationalacademies.org/hmd/~/media/files/activity files/nutrition/dri-tables/8_macronutrient summary.pdf?_ga=2.174873826.1592573937.1533305663-499315850.1533305663
  3. Albahrani, A. A., & Greaves, R. F. (2016). Fat-Soluble Vitamins: Clinical Indications and Current Challenges for Chromatographic Measurement. Clin Biochem Rev.,37(1), 27-47. Retrieved from http://vr2pk9sx9w.search.serialssolutions.com.proxy1.lib.uwo.ca/?sid=Entrez:PubMed&id=pmid:27057076
  4. The Facts on Fat. (2018). Retrieved from http://www.cci.health.wa.gov.au/docs/The Facts on Fat 25-01-18.pdf
  5. Making Sense of Serving Sizes. (2018). Retrieved from http://www.cci.health.wa.gov.au/docs/Making Sense of Serving Sizes 25-01-18.pdf
  6. Introduction To Protein And High Protein Foods. (2017). Retrieved from http://www.unlockfood.ca/en/Articles/Protein/Introduction-To-Protein-And-High-Protein-Foods.aspx

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