Nutrients, the fundamental basis of any diet
Nutrient is any substance in food and that we needed to live and stay in health. Essential nutrients are those that the body can not synthesize (from others) and therefore completely dependent on food intake. Human nutrition as a science is very recent and, indeed, the discovery of 40 or 50 essential nutrients occurs in the last decades of the nineteenth and first third of the twentieth century.
The nutrients that provide energy are called macronutrients and consist of: 1) proteins 2) the fat and 3) carbohydrates.
1) Protein is our structure and are therefore essential for growth, renewal thereof and for the synthesis of many substances related to our immunity and cellular enzymatic reactions.
2) The fat is the quintessential energy nutrient (1 gram of fat provides 9 kcal, compared with 4 Kcal of proteins and carbohydrates) also supply essential fatty acids provide the body with fat soluble vitamins A, D, E and K. Its intake is essential, although the excess of their contribution, especially saturated fat (as in the normal diet of developed countries) is detrimental to health.
3) Carbohydrates have a fundamental role is energy: the energy is more user friendly. Their input has a protein sparing action and avoidant of ketogenesis. The recommended daily intake and sedentary healthy adult is 3 to 5 g / kg / day, or about 200-300 g / day.
Vitamins and minerals have no energy function but are essential to life because they are involved in many cellular processes.
There are two types of vitamins in our diet:
· Soluble: 8 B vitamins and vitamin C.
· Soluble: vitamins A, E, D and K.
We need about 18-20 minerals are: Calcium, Phosphorus, Magnesium, Iron, Manganese, Zinc, Copper, Cobalt, Chromium, Molybdenum, Iodine, Fluorine, Sodium, Potassium, Chlorine, Sulfur, Selenium, Nickel, Tin and Silicon .