All About Macronutrients

Find out all about macronutrients in this fascinating article!
All About Macronutrients
Saúl Sánchez

Written and verified by el nutricionista Saúl Sánchez.

Last update: 12 June, 2023

Macronutrients are the substances found in the highest proportions in our food intake. They’re present in almost all foods and are the fuel for our bodies. In addition, they’re related to many physiological reactions that take place on a daily basis.

We can distinguish 3 types of macronutrients: carbohydrates, proteins and fats. Only with one of these – carbohydrates – can we limit their consumption and not harm our health if we aren’t suffering from a pathology. Reducing the intake of fat and protein below what’s recommended will cause problems.

The 3 macronutrients

We will explain below the functions of the 3 macronutrients and their importance in the diet.


Also known as carbohydrates, their main objective is to ensure the obtaining of energy. They’re the body’s priority fuel when high-intensity efforts are made, in which anaerobic metabolism is started. Besides, they’re involved in the formation of certain structures at a cellular level, although this is somewhat secondary.

They’re made up of glucose units that join each other through different links, creating networks of molecules of different conformation and impact in the body. Once digested, carbohydrates are broken down again into these basic molecules to pass into the bloodstream and enter the metabolic processes for energy.

We can distinguish two types of carbohydrates according to their speed of absorption: those with a low glycemic index, or complex, and those with a high glycemic index, or simple. The latter are related to a worse state of health, as long as they’re consumed outside of the sports context and on a recurring basis. This is confirmed by a study published in the Journal of Hepatology.

However, despite the fact that it’s possible to consider a diet very low in carbohydrates (in a way that doesn’t affect our health) it’s also possible to introduce a certain amount of complex carbohydrates in the daily diet and obtain a benefit from them.

Foods with a high content of them are usually characterized, at the same time, by presenting fiber in a representative dose. This substance has been shown to be beneficial for intestinal health, which affects the functioning of many other systems in the human body.

In any case, it’s important to choose whole-grain food with carbohydrates. This is how we make sure that they don’t cause pancreatic stress and contain plenty of fiber.

Some carbohydrates with macronutrients.
Carbohydrates usually provide fiber, but must be regulated in contexts of sedentary lifestyle.


Proteins are macronutrients made up of simple units called amino acids. They have various functions, including the construction of tissues. In addition, they catalyze physiological reactions and guarantee hormonal balance.

Its daily consumption is essential, otherwise, a dysfunction could be caused that would end in pathology. In fact, a high intake of them is related to better muscle mass health, according to research published in the journal Nutrients.

Although in previous times it was recommended not to exceed a dose of 0.8 grams of protein/kilogram of body weight/day. At present, it’s advisable to guarantee at least the contribution of 1.2 grams/kilogram of body weight/day.

Proteins are classified into two groups, based on their biological value. This denomination refers to its amino acid content and the digestibility of the nutrient. In this way, proteins of high biological value are those that come from foods of animal origin and are characterized by containing all the essential amino acids in their composition.

On the other hand, those of low biological value come from foods of plant origin and are usually deficient in at least one essential amino acid. This implies that in order to obtain a quality nutrient it is necessary to combine several different plant foods with a high protein content, thus seeking to overcome this limitation.


Lipids or fats are macronutrients that are considered part of our reserves, although in reality they perform many other functions in the body. One of them, for example, is to guarantee homeostatic balance. They’re also important because they’re a reservoir for fat-soluble vitamins, such as D and A.

It should be noted that, from an energy point of view, lipids are the nutrients that provide the most calories. Whereas carbohydrates and proteins contain about 4 kilocalories/gram, fats have 9 kilocalories/grams. For this reason, we shouldn’t spend too much on their intake, since otherwise we could unbalance the energy balance.

There are several different types of lipids, depending on the nature of their chemical bonds. We can classify them into two large groups: saturated and unsaturated fats. The former are characterized by presenting simple bonds and for being solid at room temperature, while the latter have complex bonds and remain in a liquid state.

Within unsaturated fats, we can continue making other classifications, although the important thing is to keep in mind that these macronutrients stand out for their ability to modulate inflammation in the body. There’s evidence that their regular intake is capable of preventing the development of certain complex pathologies, such as cardiovascular diseases.

There’s a last group of fats based on the spatial configuration of the molecules that compose them. Typically, lipids are oriented in the cis position. However, when subjected to high temperatures, they can change their disposition, becoming trans-type.

Although both saturated and unsaturated fats are considered beneficial for health, trans fats can increase inflammation and promote the development of complex pathologies.

The importance of a balanced diet

Many times we talk about a balanced diet to exemplify the concept of healthy eating. By this, we’re referring to a diet that contains the proportion of macronutrients recommended in a normocaloric situation, which doesn’t generate weight gain or loss.

In this sense, it’s worth noting the need to guarantee a regular and high intake of fats and proteins, since they’re the macronutrients that perform the most diverse functions within the body. Contrary to what was previously believed, it’s best to reduce or limit the intake of carbohydrates in sedentary people.

It’s true that the latter can appear more or less regularly in the diet, although it’s essential to monitor their origin. Optimally, they will be obtained from the consumption of whole grains with a low level of processing.

In this way, we avoid a lack of glycemic control that could produce subsequent pancreatic stress. This situation could increase the risk of metabolic pathologies in the medium term, such as type 2 diabetes.

On the other hand, it’s essential to limit the consumption of simple sugars. These nutrients can make sense within the framework of sports nutrition, as they provide fast and optimal energy for maximum effort.

However, in the context of sedentary people, they create an impact on the body that isn’t beneficial at all. In fact, the association of simple carbohydrates with obesity has been more than proven.

Foods with fatty acids.
Omega 3 fatty acids are linked to cardiovascular health protection.

Where macronutrients come from matters

Many current diets are based on calculating the macronutrients necessary for a given subject, neglecting the foods that provide them. Under this type of eating plan, the consumption of almost any product is allowed, as long as it’s framed in the corresponding mathematical calculation.

However, this model is dangerous, since the provenance of the nutrients matters and often determines their healthiness. We have a very clear example with fats.

We can make a more or less exact calculation of the optimal intake of these macronutrients. However, it isn’t the same to satisfy this demand through fresh foods than through processed products, in which the configuration of the lipids has changed to the trans type. In the latter case, we would be harming our health.

The same happens in the case of proteins. It isn’t the same to provide 70 grams of a nutrient of animal origin, of high biological value, than the same protein grammage coming from plant-based food, which is deficient in some essential amino acid and with low digestibility.

In the context of vegan diets, for example, it would be necessary to increase protein consumption, in addition to making a correct combination of foods that contain them.

Because of this, it’s very important to pay attention to the food we include in the diet, apart from its nutritional value. It’s best to choose fresh food, with minimal or no industrial processing. In this way, we also avoid the addition of chemical substances to increase the food’s conservation.

Macronutrients are a key part of the diet

Macronutrients are important elements in a person’s diet. Providing the necessary nutrients is a key point when it comes to ensuring the quality of food. In fact, a failure in this aspect can lead to the development of different illnesses related to the functioning of the body’s systems.

It isn’t only necessary to focus on this data, but also to assess the quality of the foods that provide the nutrients that are needed. In addition, within each group of macronutrients, there are different qualities and benefits.

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