Introduction to macronutrients

Updated on March 14th, 2024

Familiarize yourself with nutrition

Nutrients are all the compounds in food that are used directly, or indirectly with the help of bacteria, by your body to perform its amazing functions. Nutrients have various roles: to produce energy, create building blocks and help with special cellular functions.

There are many types, some are essential and cannot be produced by the body itself and some can be made from precursors within the body [1]. A good example of that is proteins. Your body is continuously breaking down and building up a wide variety of proteins, but to do that it needs amino acids and 9 are called essential amino acids because they can only be supplied by food.

Nutrients are classified into macronutrients and micronutrients, macros and micros in short. Macronutrients are required in large quantities and micronutrients in relatively small quantities. Macronutrients consist of fats, proteins, carbohydrates, and fibre. On the other hand, vitamins and minerals make up the micronutrients, tiny essential molecules that do a lot of good! [2] [3] [4] 

Introduction to macronutrients

Macronutrients are known as energy-providing nutrients and the building block of cell components [3] [4]. At the energy level, lipids give the most energy (9kcal per gram of lipid), followed by proteins and carbohydrates that give the same amount of energy (4kcal per gram) [3]. Keep reading to know the additional functions and roles that macronutrients fulfill.


The most controversial f-word in the world: fat. But no need to scream in despair and cut it out of your diet completely. This macronutrient is actually one of the body’s main energy sources. Fat is crucial for the maintenance of the cells in our body, our hormones, and for proper brain function. Still, some fats are better than others. [1] 

Saturated Fats

Saturated fats are known as ‘bad fats.’ They are mostly found in animal-derived products such as butter, meat, whole milk and tropical oils such as palm oil or coconut oil. They are solid at room temperature and are not susceptible to oxidation, or to turning rancid when exposed to air. Saturated fats have only single bonds in their atoms. [2] 

Risks of saturated fats

The role of saturated fats on health has been widely analyzed, where studies have shown that consuming excessive amounts of these fats may raise cholesterol levels, and in the long term, increase heart disease risk by promoting blood clotting. Therefore, it is important to limit the amounts consumed per day and opt for unsaturated forms of fat. Other fats associated with health risks are trans fats. 

Trans fats

Trans fats are primarily formed through hydrogenation, a process used by food manufacturers to convert liquid oils into solid fats, typically to increase their stability, shelf life and texture of processed foods. Studies have found that eating foods high in trans fats can raise LDL ("bad" cholesterol levels and lower HDL (“good”) cholesterol levels in our blood, as well as cause inflammation, which is linked to increased heart disease risk. [5, 6]

Unsaturated fats

Unsaturated fats are known as ‘good fats'. They are mostly found in plant-derived products such as sunflower oil, flaxseed oil, avocados, nuts, and whole grains. If they are not hidden inside a food, unsaturated fats are liquid at room temperature because of having both, single and double bonds in their structure. [2] 

Monounsaturated fats

This type of fat contains only one double bond in its structure. You can obtain them from olive oil, avocados, peanut oil, sunflower oil, and canola oil. They are recommended over saturated fats, as they are thought to reduce "bad" cholesterol. [7]

Polyunsaturated fats

This type of fat contains two or more double bonds between its carbons. The main food sources you can obtain them from are corn oil, flaxseed oil, soybean oil, sunflower oil and oily fish (such as salmon, mackerel and sardines.) The different types of polyunsaturated fats are Omega 3, 6 and 9. The first two are essential fats because they’re needed for the different body functions, but our body is not able to produce them on its own. Hence, you can only obtain them through food. On the other hand, Omega 9, while not essential, still provides various health benefits. [7] 

Omega-3 fatty acid

Omega-3 plays an active role in the maintenance and development of the retina (eyes), skin and brain. The 3 most important omega-3 are: alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). [8]

Alpha Linolenic acid (ALA)

Linolenic acid (ALA) is commonly found in seeds and plant oils, such as flaxseed, sunflower oil, and algae. The human body converts ALA to eicosapentaenoic acid (EPA). The absorption of direct EPA in the body is however much more efficient than when it’s obtained from ALA first. [8, 9]

Eicosapentaenoic acid (EPA)

Eicosapentaenoic acid (EPA) is commonly found in aquatic animals such as fatty fish. Your body can also naturally convert the ALA into EPA itself. Studies have shown that intake of large doses of EPA (more than 2.0 to 4.0 g/day) can lower inflammation in the body. [8, 9]

Docosahexaenoic acid (DHA)

Docosahexaenoic acid (DHA) is also found in aquatic animals such as fatty fish but also in seaweed. It’s the most common omega-3 fatty acid present in the brain and retina. DHA also gets transmitted through breast milk. Some studies claim that this makes it an important nutrient during pregnancy and lactation. [8, 9]

Omega-6 fatty acid

Linoleic acid (LA) is the main omega-6. These fatty acids are much more common than omega-3 fatty acids and are found in the vast majority of the foods we eat: whole-grain bread, wheat, most vegetable oils, and cereals. [9, 10]

Omega-9 fatty acid

Omega-9 is a nonessential fatty acid. Also known as oleic acid, our body can create this fatty acid from other sources, for instance, from the unsaturated fats we eat. This fatty acid boosts our energy levels and brain function. Nevertheless, further research is still needed to understand the roles of this fatty acid more precisely. [9, 11]


Protein is one of the main building blocks of the human body. It’s necessary for the growth, restoration, and maintenance of body cells tissues, bones, skin, and muscles. 

No wonder it’s called protein, meaning: of prime importance. Most people associate protein with muscle building, but did you know your muscles work non-stop, even when you sleep? That is why your body needs a steady supply of protein. Proteins are made up of amino acids. But what are they exactly? [1, 9]

Amino acid

Amino acids (AA) are the main components of proteins. One protein can have less than 100 to over 30.000 amino acids, and they all have the same structure: a central carbon atom with a hydrogen atom, an amino group, an acid group and a side group that can vary. The variation in the side group determines the type of amino acid. Depending on several factors, they’re categorised as essential, conditionally essential or nonessential. [1, 9] 

Essential AA

Essential amino acids are the ones that the human body is either incapable of producing, or can’t make sufficient amounts of it. It’s, therefore, crucial to include these in your diet. Foods high in essential amino acids are: eggs, soy protein, buckwheat, whitefish, chicken, meat, and seeds (hemp, pumpkin, chia, sesame.) There are nine essential amino acids: Histidine, Isoleucine, Leucine, Valine, Lysine, Methionine, Phenylalanine, Threonine and Tryptophan. [9] 


Histidine provides structure to haemoglobin. Haemoglobin is the blood protein in charge of transporting oxygen to the majority of our cells and tissues. It also controls the immune response in your skin. [9]

Isoleucine, Leucine, and Valine

This trio is called ‘branched chain amino acids’ (BCAA). They are directly and strongly involved in muscle growth by enhancing the genetic signalling sequence called mTOR. Additionally, these AAs also participate in the absorption of glutamine, alanine, and important elements such as nitrogen and carbon. [9, 12, 13]


Lysine controls the production of nitric oxide. Nitric oxide is a molecule that causes our blood vessels to widen, which supports the transport of nutrients and other important molecules through our body. [9]


Methionine contains sulfur, which is a molecule that protects your tissues, modifies DNA and maintains the proper functioning of your cells. It also balances out the production of nitric oxide and substances that protect your cells from environmental stress situations, such as the risk of infections, and lack of food, water or oxygen. Methionine is involved in the creation of the nonessential amino acid cysteine, which is another sulfur-containing AA important for your body to have. [14, 15] 


Phenylalanine is key for the activation of nitric oxide (the molecule that causes blood vessels to widen) the production of tyrosine (which improves attention and focus) and the neurological development of brain cells. [9]


Threonine produces important proteins that help your immune system stay strong and benefit your gut health. This AA is also needed for the development of the nonessential amino acid named glycine. [9]


Tryptophan limits the production of the inflammatory cells called cytokines. They put the body in flight-mode, which is an undesired effect when you don’t actually have to run away from a pack of wolves. It also has antioxidant properties, which means it protects our cells from the effects of free radicals. These free radicals cause ageing, damage your tissue, and likely cause some diseases [9, 16]

Nonessential AA

Nonessential amino acids are AA that the body is capable of producing itself. It creates them from carbs, fat and nitrogen-containing foods. The 11 nonessential amino acids are Alanine, Arginine, Aspargine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine, and Tyrosine. [9]


Alanine provides energy for both our muscles and brain. It acts as a buffer in our muscles, which makes them perform better. This buffering activity consists of regulating the acidity level (pH) in the muscles that get influenced by the different cycles our body works on throughout the day. Alanine also helps with the creation of simple sugar in our liver. [17, 18] 


Arginine is involved in wound healing and in the production of hormones. It also participates in the detoxification of ammonia. Ammonia is a waste product generated after the digestion of proteins. [9, 13] 


Asparagine is involved in the control of cell functions in the brain. It’s also responsible for the detoxification of ammonia. Additionally, it regulates the gene signals that make our immune and nervous systems function properly. [9]

Aspartic acid

Aspartic acid plays a role in the normal functioning of the nervous system. It also assists in the production and release of hormones. [9] 


Cysteine contains sulfur and is involved in various physiological processes. Sulfur-containing compounds are synthesized from cysteine as needed for different functions. Sulfur helps with wound healing and the breakdown of substances external to the body (such as food and medicine.) Cysteine also has an active function as an antioxidant. [19] 


Glutamine is the most abundant AA in the body and the main one involved in muscle growth. It's like fuel for certain cells in your immune system, which might get depleted when you do a lot of really intense exercise. Also, it might help your muscles store energy (glycogen) better, and some research suggests it could make your muscles stronger. Additionally, this amino acid enhances gene expression, immune function and provides energy to the absorptive cells in your small intestine. [13, 20]

Glutamic acid

Glutamic acid will become glutamate in the body. Glutamate is one of the main neurotransmitters in the brain. It is also essential for protein repair, regeneration and growth. As you can tell by its name, it takes part in the production of Glutamine as well. Together with glutamine, it also sustains the nitrogen balance in our body. [20]


Glycine improves the entrance of calcium into our cells, it acts as neurotransmitter in central nervous system. It also participates in the production of DNA units. Furthermore, it regulates the development of both signaling molecules and heme-proteins (which are involved in oxygen transport in our tissues and organs). It also acts as an antioxidant and anti-inflammatory. [9, 31]


Proline contributes to the formation of collagen. This is the main structural unit of the tissues that connects, supports or separates our organs. Proline also helps to kill pathogens (bacteria and viruses) by strengthening the immune system. [21]


Serine contributes to protein synthesis, and the production of essential DNA units. It also activates important receptors in our brain, thereby improving the signaling of neurotransmitters that keep up the communication within the brain. [9]


Tyrosine has most of the functions the other amino acids have: it promotes protein-production, is anti-inflammatory and it has antioxidant capacities. [9, 13]

Conditionally essential AA

Sometimes, a nonessential amino acid can become conditionally essential. For instance when the diet doesn’t supply enough amounts of the nutrients needed to form them, or when you are under a certain disease and the conversion of one amino acid to another can’t be fully done. This is especially true during times like growth, illness, or pregnancy.

In other words, when the need for the AA exceeds the body’s ability to produce it. But it's important to note that all 20 amino acids, along with their byproducts, are necessary for normal cell function and health. [1, 22]


Carbohydrate is the collective name for the sugars, starches, and fibres that can be found in fruits, grains, vegetables, and dairy products. Carbohydrates are your body’s main energy provider. They also keep your metabolism running and your blood sugar levels stable. Carbohydrates are divided between simple carbs (monosaccharides and disaccharides) and complex carbs (polysaccharides). [1, 23] 

Monosaccharides (simple carbs)

Monosaccharides are the most basic form of carbohydrates and the simplest form of sugar. They contain only one sugar unit. Generally speaking, the body absorbs quickly this type of carbs because of having such a simple structure. The three different monosaccharides are glucose, fructose, and galactose. They all have the same kind and numbers of atoms (carbon, hydrogen, and oxygen) but differ in their arrangement. This gives each of them a different level of sweetness. [1, 24]


Glucose, meaning ‘sweet’ in Greek, is the most common monosaccharide. Our body breaks down some of the carbohydrates we eat into glucose, which serves as our body’s essential energy source. When it travels through our bloodstream to our cells, it’s called blood sugar, and the hormone insulin is the one in charge of moving the blood sugar into our cells. People that have diabetes have excessive amounts of glucose in their blood because their insulin balance is not working properly. [25]


Fructose occurs naturally in fruits and vegetables. Thanks to its structure, it is known to be the sweetest sugar of them all. Fructose has the ability to stimulate our taste buds twice as much as glucose. Therefore, you would need less of it for sweetening purposes. [1, 9, 32] 


Galactose is the main carbohydrate component in milk and dairy products. It’s less sweet than glucose and fructose, but it’s still quite close to glucose in structure and taste. It‘s an important component in the central nervous system development in infants, hence its nickname ‘brain sugar.’ [9]


Disaccharides are a slightly more complex form of carbohydrates, but still easy to digest. They contain two sugar units, as they are made when two monosaccharides are paired up. For example, if you combine glucose with galactose, you get the milk sugar lactose. As you can tell, the structure of disaccharides is a bit more complicated than monosaccharides. Therefore, it takes longer for our body to digest and absorb them. [1, 24] 


Maltose consists of two glucose units bound together. It is commonly found in grains such as barley and is produced during the digestion of starches. Maltose is less sweet than glucose by itself so it is a less common sweetener in foods. [9] 


Sucrose, also known as table sugar, is formed when combining fructose and glucose. Since it contains fructose (which is already really sweet) you can imagine this is the sweetest disaccharide out there. Sucralose, a non-caloric sweetener is produced out of sucrose to be used as sugar substitutes. This is 600 times sweeter than normal sucrose. Several studies claim that sucralose is poorly absorbed in the body, and therefore the majority of it will be disposed of without influencing your blood sugar levels. [26]


Lactose is the main sugar found in human breast milk. It's made up of two smaller sugars, glucose and galactose. The female body produces it in the mammary glands, regardless of what the person eats. Besides providing energy, lactose is essential for making important molecules in the body, like certain types of sugars, proteins, and fats. It also helps the infants body absorb and hold onto calcium, magnesium, and zinc. Lactose is broken down by an enzyme called lactase in the small intestine and then absorbed into the body. However, some people have trouble digesting lactose due to a deficiency in lactase. This can cause symptoms like stomach pain, bloating, gas, and diarrhea. [33]

Polysaccharides (complex carbs)

Polysaccharides are the most complex form of saccharides and take the longest to be broken down by the body. They are formed when a lot of saccharides are combined. For example, when many glucose molecules are connected together, you get glycogen, a polysaccharide that stores energy in your muscles and liver for future use. In food, there are other non-digestible polysaccharides with different structures and we put them all together as dietary fibres. [1, 24] 


Dietary fibres come in different types, including cellulose, hemicellulose, chitosan, pectin, β-glucan, gum, and lignin. These fibres can't be broken down by digestive enzymes in humans. This enables it to reach our intestines, where it turns into dinner for our hungry gut bacteria. Fibre slows down the rate in which sugar is absorbed into the bloodstream, reducing the risk of heart disease and diabetes. They can also enhance the movement of food through our digestive system depending on if they are soluble or insoluble. These fibres are found in foods like whole grains, fruits, vegetables, and seaweed. [27, 28, 34] 

Soluble Fibre

Soluble fibres are able to dissolve in water and turn into a gel during digestion. This will slow down digestion and the emptying of the stomach and the absorption of nutrients, including glucose, in the small intestine, leading to a more gradual increase in blood sugar levels after a meal. Also, this gel formation will make our stools firmer and more regular. Furthermore, soluble fibre is prebiotic, meaning it boosts the population of good bacteria in our intestines. Soluble fibres slow down the digestion process and can increase the bulk of food in the digestive tract, which can lead to a sensation of fullness and help regulate appetite. Therefore, fighting hunger is easier with foods high in soluble fibre such as oats, black beans, lentils, barley, avocados, apples, and strawberries. [9, 29, 30]

Insoluble Fibre

Insoluble fibres don’t dissolve in water, which means that they can’t form gels. They enhance the movement of material through our digestive system and increase the amount of stool. This has a relieving effect for those who suffer from constipation or irregular stools. Foods high in insoluble fibres are wheat bran, whole-wheat bread, brown rice, carrots, broccoli, and green beans. [9, 29, 30]

In conclusion, understanding macronutrients is essential for maintaining a balanced and healthy diet. Macronutrients, including fats, proteins, carbohydrates, and fibre, play vital roles in providing energy, building cellular structures, and supporting various physiological functions. It is important to consume macronutrients in appropriate quantities to meet the body's needs and promote overall well-being. By incorporating a diverse range of nutrient-rich foods into our diet, we can ensure that we obtain the necessary macronutrients to support optimal health and functioning of the body. Additionally, being aware of the different types of fats, proteins, and carbohydrates can help make informed dietary choices and contribute to long-term health and vitality.


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