Proteins (composed of amino acids), carbohydrates (sugars) and lipids (fatty acids) constitute the 3 main families of macronutrients or organic molecules in the body. On the other hand, as as we recently remindedminerals, trace elements and vitamins are considered micronutrients. Micronutrients and macronutrients are all essential to the metabolism and must be obtained from outside the body through the diet or through food supplements since most of them cannot be synthesized (manufactured) by the body.
Proteins are recognized as acidifying elements
The proteins that make up most of the supporting and protective tissues of the human body are found in muscles, tendons, cartilage, collagen, skin, hair and nails. It is also found in enzymes that accelerate many essential biochemical reactions. They are involved in the processes of muscle contraction and body defense (immune system), in some blood exchanges and transport (hemoglobin) or they are included in a large number of essential hormones. The very complex structures of these macromolecules are composed of acidic amino acids. From a dietary point of view, proteins are mainly present in meat and fish, but also in dairy products. There are vegetable proteins in legumes and cereals. If you are interested in nutrition, you know that proteins are known to be acidifying elements for the body. Indeed, their digestion and fragmentation lead to the production of urea and ammonia because of the Nitrogen (N), Sulfur (S) and Hydrogen (H) they contain. These acidic elements are aggressive to the body.
Carbohydrate, the most accessible source of energy
Among the carbohydrates, there are different types of sugars such as glucose, sucrose or fructose. All these sugars are composed of small units called "bones". The chains of bones can be more or less long. Glucose, for example, consists of six basic units. Fructose is formed from the same six basic units, but they are arranged differently. It is therefore the organization of their chemical structures that distinguish these two sugars of the same family. Carbohydrates are the most readily available source of energy for all basic metabolic functions. They are vital because they keep the human body alive. In the past, they were called carbohydrates because they necessarily contain carbon atoms. The best sugars are of course natural sugars such as fructose found in fruits, honey and some vegetables. The "table sugar" is composed of a glucose attached to a fructose. Together, they form sucrose or sucrose. In this form, fructose loses the benefits it has when taken directly from fruit. Carbohydrates with simple small molecules (fructose, glucose) provided by plants (fruits, vegetables) are very bioavailable and easily used by the body. That's why they are also called fast sugars. Sugars with more complex chemical structures (notably starch, glycogen, cellulose) are provided by cereals and oilseeds. Their digestive process is longer and more expensive for the body. That's why they are called slow sugars.
Unsaturated fatty acids are beneficial to the body
Explanations of lipids or fatty acids are often more difficult because there are several families of lipids or fatty acids, which makes them more difficult to understand. The more or less long chains of lipids are composed of a glycerol coupled to one or more fatty acids. Thus coupled, they form an ester. You have probably already heard of the two main groups of fats, namely Saturated Fatty Acids (SFA) and Unsaturated Fatty Acids (UFA). The former are generally presented as bad for health and the latter as beneficial. Globally, SFAs are provided by meat and dairy products, in short, by animal products except fish. For their part, the AGI are rather found in vegetable oils and in the dry fruits and oleaginous from which they are extracted. There are also animal sources of AGI, these are fish (especially salmon, tuna, herring, sardines, mackerel, halibut).
Let's explain the distinction between the two main categories of AGI
On the one hand, there are monounsaturated fatty acids [leader = oleic acid or omega-9 (Ω9) among others in olive oil] and on the other hand polyunsaturated fatty acids. Polyunsaturated fatty acids include omega-6 fatty acids (Ω6 = linoleic acid = leader present in many vegetable oils) and omega-3 fatty acids (Ω3) including α-linolenic acid (in some vegetable oils camelina, flax, hemp...), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
In our body, α-linolenic acid (omega-3) will only be transformed into EPA and then into DHA if the intake of omega-6 (linoleic acid) is not too high. In fact, the same enzymes are responsible for the conversion of omega-6 into gamma-linolenic acid and omega-3 into DHA. The optimal balance of fatty acids should be 4 omega-6 for 1 omega-3. Paradoxically, Ω-3 are very little present in our modern diet. The ratios are frequently 15 to 20 Ω-6 to 1 Ω-3. Due to these excess Ω-6, enzymatic competition is tough and in our body Ω-3 are very difficult to convert into DHA. However, nutritionists recommend a daily dietary intake of at least 200 mg, which is far from being the case. Some fatty fish especially those from cold seas contain Ω-3 of the DHA type. Their contributions are to be privileged since it saves a costly and often deficient conversion to our body. We can also get this type of Ω-3 thanks to certain vegetable oils such as hemp, camelina, flax or in a lesser proportion that of colza or walnut.
Most vegetable oils contain fatty acids belonging to the different categories mentioned above in varying proportions. In order to benefit from these different contributions, it is therefore recommended to vary the lipidic food sources. We can see here all the complexity of foods that are a clever mix of several macronutrients and many micronutrients.