A nutrient is a substance essential to the body for the maintenance of life, its growth and the renewal of its structures. We can distinguish the nutrient family into two main groups: macronutrients and micronutrients.
Macronutrients vs Micronutrients
The former are those that are supplied to the body in greater quantities, while the latter are introduced in small quantities. Macronutrients are divided into carbohydrates, proteins, fats, fibers and water. Micronutrients are divided into vitamins and minerals.
In most food, there are tons of nutrients present in different proportions; therefore, it is useful to remember that in a balanced diet it is necessary to take into account not only the number of calories contained in food but above all the presence of the nutrients found in it.
Carbs are used by the body as fuel, they make about 4 kcal per gram and we find them mostly in starches, cereals, bread, legumes, fruits, potatoes, honey, flour, dried fruit and jams. Carbs are divided into two main categories:
- Sugars or simple carbohydrates (monosaccharides and disaccharides)
- Starches or complex carbohydrates (oligosaccharides and polysaccharides)
Simple carbohydrates are composed of hydrogen, carbon, and oxygen which make sugar molecules, hence the term monosaccharides, or the bond of two monosaccharides, which gives them the term disaccharides. They are simple carbohydrates, for example: fructose, glucose and galactose.
Carbohydrates made up of a union of 3 to 10 units of simple sugars are called oligosaccharides. The more complex carbohydrates, those composed of a large number of monosaccharide units, which can be several thousand, are called polysaccharides.
They are complex carbohydrates, belonging to the group of oligosaccharides:
- maltodextrins, which are made up of short chains of glucose molecules, which makes them easily digestible but not as quickly as simple sugars; thanks to this characteristic, maltodextrins ensure a slow and long-lasting release of energy, and are therefore very suitable as a supplement to be taken during workouts.
- fructooligosaccharides (FOS) and galactooligosaccharides (GOS), which are composed of fructose and galactose molecules; not being completely digestible, these nutrients arrive intact in the final part of the intestine (colon), where they are useful for the selection of beneficial bacteria, useful for the body.
We can find polysaccharides in foods rich in starches (cereals, potatoes and many other types of vegetables). Both carbohydrates provide energy to the body but, while the former tend to create sudden fluctuations in the level of glucose in the blood (with the effect of causing energy levels to rise dramatically over a period of limited time, only to drastically lower them) complex carbohydrates, during the digestive processes are broken down into simple units in order to be absorbed.
Thanks to this mechanism, complex carbohydrates provide energy more slowly, but for longer periods, avoiding the aforementioned fluctuations in blood sugar. Carbohydrates generally represent the largest portion of the food ration, varying on average from 50% to 80% of the daily total, based on individual needs and requirements.
Proteins And Amino Acids
Proteins are organic substances made up of four main elements: Carbon, nitrogen, oxygen and hydrogen. They also provide about 4 kcal per gram and cover a large number of vital functions for the body, such as:
- plastic processes: that is, building all the tissues that are subject to continuous demolition and synthesis, this is helpful in your muscles.
- regulatory processes: proteins being precursors of hormones, neurotransmitters, enzymes and other molecules of biological importance, proteins regulate their production and functioning in the organism.
- energetic processes: the body can transform proteins into energy by splitting them into amino acids and removing the nitrogenous part, resulting in their conversion into glucose (see glucogenic amino acids).
Although there are many amino acids present in living organisms, only some of them (about 20) are responsible for the formation of proteins. We can distinguish these amino acids into two main groups: essential and non-essential, although the latter category adds a minor subgroup, called semi-essential.
Essential amino acids: phenylalanine, isoleucine, lysine, leucine, methionine, threonine, tryptophan and valine; they are vital because they cannot be synthesized by the organism, they must appear in sufficient quantities in your daily dietary ration.
The non-essential: arginine, histidine, alanine, L-aspartic acid, L-glutamic acid, glycine, proline, serine, asparagine, glutamine; if they are not present, they can be synthesized through the transformation of other amino acids.
The essential seeds: taurine, tyrosine and cysteine; these nutrients can be synthesized by the body from phenylalanine and methionine, a condition that these precursor amino acids are supplied appropriately.
Also called lipids, they are organic molecules present in nature and grouped by their common characteristics of solubility: they are insoluble in water, while they are soluble in non-polar organic solvents, such as ether and acetone. Lipids are often and unfairly demonized for their high caloric content (9 kcal per gram).
However, their contribution is of vital importance and they must still be present in your daily food ratio. Even if in moderate quantities , since they perform multiple functions, such as:
- convey fat-soluble vitamins
- promote the regulation of different hormones in the body
- provide for thermal insulation and protection of the various internal organs, tendons and joints
- synthesize steroid molecules, such as some hormones
Lipids also play an important role in the immune system and metabolism, and have anti-inflammatory and anti-allergic functions.
Fats can be, as for proteins, of animal and vegetable origin. Generally, animal fats are solid at room temperature, while vegetable fats are liquid.
They cannot be synthesized by the human body except in minimal quantities, they perform many functions in the body, regulate many metabolic reactions and play a key role in the immune system. They are classified into two main groups:
- Water-soluble vitamins (B vitamins, including folic acid, vitamin H, PP and vitamin C)
- Fat-soluble vitamins (vitamins A-D-E-K-F).
Water-soluble vitamins cannot be accumulated by our body and need to be introduced through food intake.
The fat-soluble ones are instead absorbed together with dietary fats and accumulated in the liver. Their possible shortage is manifested following a lack of intake for a long time.
Minerals perform both a catalytic action in metabolic processes and a structural action in some tissues, such as those of bones, teeth and hair.
They are mainly divided into macro constituents: calcium, phosphorus, sodium, potassium, chlorine, magnesium, sulfur and micro constituents: iron, zinc, copper, iodine, selenium and cobalt.