What are proteins and what do they do?
They are the nutrients that perform a greater number of functions in the cells of all living things. They are part of the structure of the tissues and on the other hand, they have a metabolic and regulatory function.
In the diet, one can distinguish between proteins of vegetable origin or animal origin.
- Vegetable proteins are found in nuts, soybeans, legumes, mushrooms, and cereals.
- Proteins of animal origin are found in meat, fish, poultry, eggs and dairy products.
The main cause of resting energy consumption (basal metabolism) is motivated by the degradation and subsequent formation of new proteins.
Dietary proteins are used primarily for the formation of new tissues or for the replacement of proteins present in the body. However, when the proteins consumed exceed the body’s needs, its constituent amino acids can be used to obtain energy from them. However, the combustion of amino acids has a serious drawback: the elimination of ammonia and the amines that are released in these chemical reactions. These compounds are highly toxic to the body, so they are transformed into urea in the liver and eliminated in the urine when filtered into the kidneys.
Essential amino acids
The human being needs a total of twenty amino acids, of which, nine is not able to synthesize by itself and must be contributed by the diet.
These nine are called essential amino acids, and if only one of them is missing, it will not be possible to synthesize any of the proteins in which said amino acid is required. This can lead to different types of malnutrition, depending on the limiting amino acid.
The most problematic essential amino acids are tryptophan, lysine, and methionine. Its lack is typical in populations where cereals or tubers form the basis of food.
Essential amino acid deficits affect children much more than adults.
Daily protein needs
The amount of protein that is needed in the daily diet depends on many factors, on the age (during the growth the needs double or triple), the state of our intestine and kidney, on which the absorption capacity will depend and also on the biological value of the proteins we consume.
- In general, about 40 to 60 g of protein per day is recommended for an adult.
- During pregnancy, breastfeeding and growth need increase.
Proteins consumed in excess, which the body does not need for growth or for protein turnover, are burned in the cells to produce energy. Although they have an energy efficiency equal to that of carbohydrates, their combustion is more complex and leaves metabolic residues, such as ammonia, which are toxic to the body.
Proteins of animal origin are much more complex and large molecules, their biological value is much higher than those of plant origin although they are more difficult to digest.
Meat contains all the basic amino acids in proportions similar to those needed by the human body, it also has many vitamins and minerals. However, meat also has saturated fats that increase the risk of cardiovascular disease.
To obtain a balanced diet you need daily 100 to 150 gr. of meat.
When taking animal proteins from meat, poultry or fish, we also ingest all the cellular metabolism wastes present in these tissues (ammonia, uric acid, etc.), which the animal could not eliminate before being slaughtered. These compounds act as poisons in our bodies. The metabolism of vegetables is different and these nitrogen derivatives are not present. Meat toxins can be avoided by consuming animal proteins from eggs, milk and their derivatives. In any case, eggs and dairy products are always preferable to meat, fish, and poultry. In this sense, fish is also preferred to poultry and poultry to red or pork meats.
If we combine the vegetable proteins we can obtain a balanced diet.
In general, it is recommended that one-third of the proteins we eat are of animal origin, but it is perfectly possible to be well-nourished only with vegetable proteins. Of course, taking the precaution of combining these foods based on their limiting amino acids.
The problem of vegetarian diets in the West is usually rather in the deficit of some vitamins, such as B12, or minerals, such as iron.
When cooking food it is necessary to also follow a series of rules. In the kitchen of the athlete must take into account:
- Maintain the nutritional value of food
- Prepare food just before consumption
- Wash food before cooking
- Steam food, whenever possible
- Observe the appropriate cooking times and temperature
- Keep food, both raw and prepared, in good condition.
- Season properly
- To sweeten cinnamon, vanilla, anise, nutmeg …
- To salt and pepper: garlic, parsley, basil, dill, tarragon, bay leaf, thyme …
- Use the right culinary technique
- For meats, fish, and potatoes: fried
- Pasta, rice, potatoes, vegetables and soft meat: boil
- Potatoes, vegetables, and fish: steaming
FOODS RECOMMENDED NOT RECOMMENDED Drinks of different types Mineral water, tea, fruit juices, tomato or carrot juice, electrolytic drinks Sweet refreshing drinks, alcohol and stimulant drinks. Broths Fish or vegetable broths items Fatty broths, lentil soups, beans. Meat and meat products Lean meat, lean meats, poultry and game Fatty sausages Breaded, bacon, smoked. Pasta, rice and cereals Wholegrain flakes, pasta, brown rice and wheat germ High fat and spicy preparations fruit Fresh fruit, fruit compote Unripe fruit and dried fruits, especially before sport Eggs Boiled eggs, French omelette, eggs on the plate, broth with an egg yolk Raw eggs, egg salad, mayonnaise Milk and derived products Milk to drink, lean cheeses, cottage cheese. All fatty cheeses. It is not recommended to drink milk after a sports test Butter Butter, vegetable margarine Pork butter, cocoa butter Bread and pastry products Wholemeal bread, whole grain biscuits, mixed bread, biscuits, simple cakes, whole-grain cookies Fresh bread, puff pastries, empanadas, cream cakes, churros, fritters, pork products Fish Boiled, fried or grilled little fatty fish. Fatty fish, canned, breaded, breaded or fried forms. Potatoes Mashed potatoes, potatoes cooked with skin All those that have fat: tortilla, sauteed, fried, etc. Vegetables Fresh and multiple pureed vegetables All flatulent: cauliflower, Brussels sprouts, cabbage, etc.