Proteins contain carbon, hydrogen, oxygen and nitrogen and are made up of smaller units called amino acids. Some, a total of nine, such as histidine or tryptophan, are essential for our body. What does this mean? That the body does not obtain them on its own but has to look for them in food.
A protein can be made up of 300 or more amino acids, the sequence and number of which are specific for each one of them. They work in a similar way to how the letters of the alphabet do: depending on how the amino acids are organized, different types of proteins are created.
The composition of amino acids, therefore, is the key to correctly selecting the foods that a healthy diet must have. If the protein has all the essential amino acids it is considered quality or of high biological value and, on the other hand, if it only has small amounts of each of them, the biological value of the protein is lower.
Those of high biological value are made up mainly of foods of animal origin, while those of plant origin tend to have a limited amount of certain essential amino acids.
Why do we need proteins?
The main function of proteins is, according to the Spanish Nutrition Foundation (FEN), to form and repair the body’s structures since they constitute the main component of the body’s cells.
Proteins are, along with fats and carbohydrates, an essential macronutrient since they provide numerous benefits: not only do they help us strengthen our immune system but they also give us a good boost to strengthen bones and muscles, as well as cartilage and skin and They support muscle contraction and movement.
In addition, they play a fundamental role in other bodily processes such as blood coagulation and fluid balance by allowing essential molecules to move around the body.
A study published in Frontiers in Endocrinology demonstrates that high-protein diets are linked to benefits such as helping to control blood sugar, promoting weight control, and increasing the body’s ability to absorb calcium.
Protein is, along with fats and carbohydrates, one of the three macronutrients without which our body would stop functioning. Its consumption, therefore, is not debatable.
How to get the proteins we need from food
Proteins can come from both animal and plant sources:
Proteins of animal origin
Why are some foods of animal origin said to be important sources of protein? As we have mentioned before, all the essential amino acids are found in foods such as eggs, meat, dairy products or fish, therefore, proteins are of high biological value.
Meat is one of the foods with the highest amount of protein. We must pay attention to red meat such as beef or lamb because, in addition to containing protein (a 100-gram beef fillet, for example, contains 21 grams of protein), they also contain saturated fats, which raise our cholesterol levels. White foods like chicken and turkey, in addition to protein, have less saturated fat, therefore, we can consume more.
Fish such as salmon or tuna will also help us meet our daily protein needs and also contain omega 3 acids. White fish such as cod, hake or monkfish, in addition to providing us with protein, are less fatty than sardines, salmon or tuna.
Dairy products are also a good source of protein, such as cheeses, with an average of 30 grams of protein per 100 grams; milk and yogurts, three to four grams per 100 grams. Dairy products can be high in saturated fat, so it is best to opt for low-fat dairy options.
According to the Food and Agriculture Organization of the United Nations (FAO), eggs are another of the foods with the highest quality protein. On average, a whole egg contains 13 grams of protein, which is mostly contained in the white, while the yolk also contains fat.
Plant foods with protein content
Not only meat provides us with proteins. Although plant-based foods have less of some of the essential nutrients, we can also use them. And we can do it with legumes, an interesting protein option that also provides us with iron and fiber. Here we include lentils and peas.
In addition to protein, legumes provide us with carbohydrates, vitamins and minerals.
Quinoa also provides us with an interesting amount of protein. Although we usually cook it as if it were a grain, it is actually a seed of a green vegetable that is related to chard and spinach. One of its peculiarities is that it contains all the essential amino acids of animal proteins.
Nuts such as walnuts also provide us with a good dose of protein and are also rich in fiber, minerals and unsaturated fats. They therefore provide healthy fats, although they should be consumed in moderation due to their high calorie content.
Whole soy foods, such as tofu or tempeh, are another excellent source of lean protein. Unlike other plant sources of protein, this time we are talking about a complete protein that provides all the essential amino acids. The best way to obtain them is in the full version.
Well combined, these ‘incomplete’ proteins result in others of comparable value to those of meat or fish. For example, the vegetable proteins in legumes improve if we combine them with cereals such as rice or bread, which contain amino acids that complement each other. Other combinations can be legumes plus a nut or a nut plus a cereal, or a legume, cereal or nut with animal protein.
How much protein do we need
The amount of protein varies depending on the person and factors such as weight, sex, activity or age. In fact, according to the Spanish Society of Dietetics and Nutrition (SEDCA), protein is the macronutrient whose requirements vary the most depending on different physiological situations such as pregnancy.
Despite everything, the European Food Safety Authority (EFSA) recommends a consumption of 0.8 grams of protein per kilo of body weight. That is, an adult weighing about 75 kilos will need about 60 grams of protein per day.
This is an approximate amount since, in certain circumstances, for example, if we are athletes, this amount is a little higher (around 1.2-1.8 grams per kilo of body weight).
The Ministry of Health also places a total recommended daily protein intake at 0.81-1 grams per kilo of weight, which translates into a consumption of between 48 and 60 grams of protein per day for a person weighing about 60 kilos.
Incorporating a variety of foods into our diet, both of plant and animal origin, guarantees sufficient consumption of total protein. Protein deficiency among European consumers is not common.