What are Macronutrients?

Nutrients. Many of us think about them regularly. Either because you try to be mindful of what you eat or maybe because you are even trying to avoid eating specific nutrients. However, it is also very possible that you have only heard of nutrients but aren’t sure what they are. Whichever is the case, you have come to the right place!

Nutrients are the organic and inorganic substances found in food. They are essential for the human body’s growth, development, and maintenance, providing the raw materials and energy required for physiological processes. The macronutrients are proteins, carbohydrates, lipids, and water. Each plays a distinct and vital role in both our food and our physiology.

Atoms and Molecules

Molecules consist of atoms, and there are an incredible amount of different combinations of atoms possible. All these combinations are responsible for the enormous variety of different food items you encounter in the supermarket.

Would you like to learn more about atoms and molecules, or do you need a brief refresher? Please check out my course on ”Biochem Basics for Food Science and Nutrition”. Here, you will find a comprehensive explanation of atoms and molecules, along with detailed information on the chemical foundation for carbohydrates, proteins, and fats. You can also take a look at the articles on molecules and atoms. You will find those under the ”Articles” section in the category ”Chemistry”.

Carbohydrates

For most people, carbohydrates are the primary source of energy. Carbohydrates can be small or large molecules, and depending on the type of carbohydrate, they serve different functions in your body.

Monosaccharides

To better understand the differences between carbohydrates, you can compare them to LEGO bricks. In this analogy, individual LEGO bricks represent the smallest carbohydrates, the monosaccharides.

Similar to LEGO bricks existing in various sizes and colours, the basic building blocks for carbohydrates can also vary. Examples of different monosaccharides include glucose, fructose (fruit sugar), and galactose. These monosaccharides are used and processed differently in the body, and they can serve various functions during physical activity. You will learn more about this in Module 2.

Disaccharides

As the name suggests, disaccharides consist of two monosaccharides. In the LEGO analogy, this would be two LEGO bricks clicked together. These can be two identical LEGO bricks or two bricks with different colours and sizes.

The same applies to disaccharides. Depending on which two monosaccharides are bonded together, disaccharides have different properties. The combination of monosaccharides in disaccharides determines aspects such as taste and how your metabolism processes the molecules. Examples of disaccharides include lactose (milk sugar), sucrose (table sugar), and maltose (malt sugar).

Oligosaccharides and Polysaccharides

Carbohydrates can be very large, easily consisting of thousands of monosaccharides. To continue with the LEGO analogy, this means that more than one brick can be attached to the first brick, and to the second brick, and to the third brick, and so on.

Carbohydrates composed of 2 to 10 monosaccharides are called oligosaccharides, and those made up of more than ten monosaccharides are called polysaccharides. Examples of larger carbohydrates include starch, pectin, and xanthan gum.

The sweetness of a carbohydrate is strongly influenced by its structure. The sweetness of carbohydrates can be relatively described. In this case, sweetness is compared to the sweetness of a sugar cube, which is assigned a value of 100. The table below provides an overview of the relative sweetness of different carbohydrates.

UPDATE Table NEEDED

Carbohydrate	Type	Sweetness
Sucrose	Monosaccharide	150
Lactose	Disaccharide	100
Fructose	Monosaccharide	70
Glucose	Disaccharide	40
Starch	Polysaccharide	0
Cellulose	Polysaccharide	0

Dietary Fibers

Undigestible carbohydrates, also known as dietary fibres, are also oligosaccharides and polysaccharides. Dietary fibres cannot be broken down by your body, but some can be digested by bacteria in the colon. The right amount of dietary fibre promotes a healthy digestive system.

How Much Carbohydrate Do You Need?

Carbohydrates are crucial for providing energy, with one gram of carbohydrates yielding approximately 4 kilocalories. The amount of carbohydrates you need depends on various factors such as your activity level, gender, age, and the amount of fats and proteins you consume alongside carbohydrates.

Would you like to learn more about how many carbohydrates you should consume? Please check out my course on ”The Basics of Food and Nutrition‘ and ”Sports Nutrition’‘. You can also take a look at the articles on food and nutrition, You will find those under the ”Articles” section in the category ”Nutrition”.

Proteins

When discussing nutrition, especially when talking about muscle development, you often hear someone mention proteins. But what exactly do proteins do, and how much protein do you need?

Amino Acids

Proteins are composed of amino acids. Similar to carbohydrates, proteins consist of chains of smaller building blocks, in this case, amino acids. Amino acids are classified by the presence of an acid group (COO-), a base group (NH3+), and a unique side chain for each amino acid.

There are over twenty different amino acids known to be relevant to humans. These can be categorized into subgroups based on different properties and their molecular structure. One criterion for grouping amino acids is whether the human body can synthesize them or if they need to be obtained from your diet.

The difference between these amino acids can be described as essential amino acids (those that must be part of your diet because the body cannot produce them), non-essential amino acids (those the body can synthesize by breaking down other substances like carbohydrates and fats), and semi-essential amino acids (those that can be produced in the body but require a limited number of different amino acids).

The table below shows the three groups of amino acids that are essential, non-essential, and semi-essential for humans.

UPDATE Table NEEDED

Essential Amino Acids	Non-essential Amino Acids	Semi-essential Amino Acids
Histidine	Alanine	Arginine
Isoleucine	Asparaginezuur	Asparagine
Leucine	Cysteïne	Glutamine
Lysine	Glutaminezuur	Serine
Methionine	Glycine	Threonine
Phenylalanine	Proline	Hydroxyproline
Threonine	Serine	Cystine
Tryptophan	Tyrosine	Valine

Just like with carbohydrates, amino acids can be linked together. The connection between amino acids is called a peptide bond. When a molecule is formed from a small number of linked amino acids, is called a peptide.

The Importance of Proteins in Your Body

Proteins serve various functions in the body. While they are used as building blocks for muscles, tendons, blood vessels, and skin, proteins play a crucial role in physiological processes such as hormone regulation and the immune system.

When exploring the importance of protein intake in relation to exercise and muscle development, it’s crucial to know that proteins can also serve as an energy source. The amount of energy provided by one gram of protein is 4 kilocalories, equivalent to the energy provided by 1 gram of carbohydrates.

How Much Protein Do You Need?

The amount of protein you need depends on whether you are considering essential or non-essential proteins. The minimum amount of protein is less critical for non-essential proteins since the body can synthesise them from other nutrients. For essential proteins, there are guidelines for the minimum daily intake. The table below provides an overview of recommended amounts established by the Food and Agriculture Organization of the United Nations.

UPDATE Table NEEDED: Overview of amino acid requirements in milligrams per kilogram of body weight per day based on age.

Source: FAO.

The amount of essential amino acids needed daily is influenced, among other factors, by how much you exercise. When the body requires many amino acids, such as for muscle building, deficiencies can occur. A shortage of one amino acid can turn a semi-essential amino acid into an essential amino acid. As the need for different amino acids can vary, it is essential to ensure an adequate total intake.

To ensure you consume enough proteins, a usual recommendation is an intake of 0.8 grams per kilogram per day. This amount is sufficient to build new muscle mass, maintain existing muscle mass, and support other bodily processes requiring proteins. Excess proteins, like excess fats or carbohydrates, are converted into reserve energy by the body.

To ensure an adequate intake of essential and semi-essential proteins, it’s important to know which foods contain which type of protein. Some protein-rich foods naturally contain all essential proteins, while others may lack one or more essential proteins.

The table below shows various foods and the amino acid that is limiting for the respective protein source.

UPDATE Table NEEDED: Protein source and limiting amino acid.

Protein Source	Limiting Amino Acid
Eggs	None
Meat	None
Fish	None
Dairy	None
Soy	Methionine
Corn	Lysine and tryptophan
Legumes	Tryptophan, methionine, and cysteine

As you can see, animal products contain all essential amino acids, while some amino acids are lacking in plant-based foods. This doesn’t have to be a problem for people who consume an all-plant diet, as long as someone consumes complementary products. Complementary products are items that, when eaten together, provide all essential amino acids.

Fats

Fat is the nutrient that can provide the most energy. One gram of fat can supply you with as much as 9 kilocalories. It is, therefore, not surprising that fat is an efficient way to store excess energy in the body.

The term “fat” is often used to describe various substances. Not all fats are relevant for sports nutrition. The fats that are primarily important are triglycerides, and we will now briefly examine them.

Triglycerides

Triglycerides serve many functions in the human body and are one of the most discussed aspects of the role that fats play in nutrition. When we talk about saturated, unsaturated, and trans fats, we are referring to the molecular structure of fatty acids. But what exactly is that?

Triglycerides are molecules composed of a glycerol molecule and three fatty acid molecules. In the image below, you can see how these molecules form a whole, with three places (indicated by R1, R2, and R3) where fatty acids can be attached.

The fatty acids, in turn, are composed of chains of atoms and can vary. These differences determine the properties of a fat, such as whether it is saturated or not and whether a fat is liquid at room temperature like oil or solid like butter.

Sterols

Sterols are fat-like molecules essential for properly functioning many physiological processes in the human body.

One of the most well-known sterols is cholesterol. Although most people are familiar with the negative impact cholesterol can have on health, it is not entirely fair.

There are different types of cholesterol, including LDL cholesterol and HDL cholesterol. LDL cholesterol is the “bad” cholesterol that can build up in your blood vessels and cause problems. On the other hand, HDL cholesterol removes LDL cholesterol and ensures it can be broken down in the liver. You could say that HDL cholesterol is the “good” cholesterol.

How much fat do you need?

As mentioned, fat provides a lot of energy, which is the primary function most fat serves in a diet. To fulfil other vital functions, such as providing fat-soluble vitamins and essential fatty acids, it is not necessary to consume a large amount of fat.

As a rule of thumb, you can say that a maximum of 35% to 40% and a minimum of 20% of daily calories can come from fat. It is important that as little fat as possible is saturated fat. In the table below, you can see an overview of the types of fat most commonly found in food and the recommended percentage in your daily diet.

Type of Fat	Recommended Percentage in Energy
Total Fat	20% to 40%, with overweight tendency: 20% to 35%
Saturated Fat	Less than 10%
Trans Fat	Less than 1%
Linoleic Acid	2%
Alpha-Linolenic Acid (ALA)	1%
Omega-3 Fatty Acids from Fish (EPA/DHA)	From 19 years: 200 milligrams per day
Polyunsaturated Fat	3% to 12%

Source: Nutrition Center

Water

The majority of the human body consists of water. Although the amount of water can vary greatly from person to person, the percentage of water in different types of cells is the same for everyone. For example, fat consists of 10% water, and muscle mass consists of 76% water. This also means that someone with a high percentage of fat relative to their weight has less water in their body than someone with the same weight but less fat and more muscle mass.

How much water should you drink?

Under normal circumstances (no strenuous activities, an environment that causes excessive sweating, etc.) an adult needs between 2 and 3 liters of water a day.

When someone hasn’t consumed enough water during exercise, there is a shortage of available water. This shifts the water balance in the body. Depending on the severity of the deficit, it can have serious negative consequences on the body’s functioning.

Because everyone is different, there are already differences in how much water someone needs without engaging in sports. For adults, it is usually recommended to drink 1.5 to 2 litres of water per day.

Target population	Age	Gender	AI
Infants	7-11 months	Both genders	0.8-1.0 L/day
Children	1 year	Both genders	1.1-1.2 L/day
Children	2-3 years	Both genders	1.3 L/day
Children	4-8 years	Both genders	1.6 L/day
Children	9-13 years	Male	2.1 L/day
Children	9-13 years	Female	1.9 L/day
Children	14-17 years	Male	2.5 L/day
Children	14-17 years	Female	2 L/day
Adults	≥ 18 years	Male	2.5 L/day
Adults	≥ 18 years	Female	2 L/day
Pregnant women	≥ 18 years	Female	2.3 L/day
Lactating women	≥ 18 years	Female	2.7 L/day

Would you like to learn more about micronutrients? Check out my article What are micronutrients?

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