To be taken in quantities of about 1ml for each calorie of energy consumed in the diet.
Usually, between that contained in food and drinks, it is better to reach about 2 liters / day. The meals of the day should be at least 5, to correctly distribute the total energy (breakfast, snack, lunch, snack and dinner).
Energy It is the result of cellular processes that use carbohydrates, lipids and to a lesser extent amino acids. The sum of the contribution of the individual three must guarantee the maintenance of all functions and normal body weight.
An average adult man needs about 2000kcal / day.
- Carbohydrates These are the most abundant energetic macronutrients. Their share must fluctuate between about 40-60% of the total energy.
- The simple and discretionary ones (table sugar and foods containing them) should be as moderate as possible and never exceed 12% of the total energy
Lipids Some are energetic and some are non-energetic
The former are mainly fatty acids, the latter sterols, phospholipids, etc. The energy ones must remain between 25-30% of the total energy; having a variable metabolic function, to ensure the state of health, most of these must be unsaturated in nature.
Cholesterol should not be introduced in excess of 300mg / dayProteins
They have many metabolic functions, but the body requires only what is necessary to compensate for the losses (the requirement increases especially with the growth of tissues).
There are some recommended percentages, but they are quite variable according to the research institutes; the same applies to the coefficient of g / kg of body weight which, on average, for adults, is estimated between 0.8 and 1.2g / kg.
Vitamins It is such a heterogeneous group that it cannot be summarized effectively
It is sufficient to keep in mind that, to introduce them all in useful quantities, the diet must be very varied and not exclude any food group. Recall that those most prone to deficiency are folic acid and vitamin D. B1 is very present in foods but the liver is unable to accumulate it.
- Mineral salts The same applies to vitamins, specifying that the elements most easily subject to deficiency are: iodine, iron and calcium; according to some also selenium.
- Sodium, contained in large quantities in table salt, may also not be used in a discretionary manner, since it is already present in foods in sufficient quantities
- Dietary fiber To be introduced for about 30g / day, it is essential for intestinal health and to modulate nutritional absorption