The A B C of a health alimentation

They are the main component of every cell. They are complex and very different molecules, even though they are composed by only 22 simple units, called aminoacids, linked in different ways. Some od the aminoacids are directly synthesised by opur organism, meanwhile 8, judged as essential, are not produced by our body and must therefore be introduced trough the alimentation. These are: lysine, tryptophan, phenylalanine, threonine, valine, methionine, leucine and isoleucine. There's a distinction between high biological value proteins - those which contain every aminoacid and particularly a consisten quantity of the essential ones -, middle and low value proteins and others.
The first commonly have an animal origin, but also those which are derviated from legumes have a good biological value. Proteins mainly have a plastic role, i.e. a supporting or filling role (they represents about the 15% of a man's weight), but also a controlling role (enzymes, hormones) and a defense role (antibodies). A good amount of proteins, especially those with essentials aminoacids, is fundamental for a good health; however, exaggeration can cause damages, because our organism, by using aminoacids in a replacing role, frees substances like urea and uric acid that must be expelled with a renal tiring work.
In the opposite side, if our alimentation lacks energetic substances (carbohydrates and lipides too), our body must use part of the proteins in order to product energy, causing a proteinic impoverishment.

CARBOHYDRAT

Most of them has a vegetal origin and is divided into simplex sugars (e.g. saccharose, i.d. ordinary sugar) and complex ones (amid and glycogen); another substance that belongs to this group is cellulose, that is not a nutriment properly becaused it cannot be absorbed by our intestine.
The most common simplex vegetal sugars are: fructose (taken from fruit) and saccharose (obtained from beet and sugar cane). In animal realm we found: glycogen, that is the glucidic reserve of muscles and liver in animal ormganisms, including man, and lactose, present in milk and its by-products.
Sugars are used as a quick and easy fuel.
Starch, mainly present in cereals, potatoes and legumes, constitues a precious source of brief eneretic reserve. Every sugar we eat is absorbed as glucose. If we assume too much sugar (simplex or complex one), a part of glucose is stored as fat.
Fibre, cosntitued mainly by cellulose, which is present in vegeatl aliment only, cannot be digested by man (differently from herbivorous animals); it has a very importante function, because by absorbing water gives volume and consistency to faeces, helping and accelerating excretion, so helping the purification of organism.

LIPIDES or FATS

It's possible to divide them in real fats, if they appear as solid, and oils, if they are liquid.
We must distinct, among alimental fats, between satured and unsatured fats (monounsatured and polyunsatured); the most part od alimental fats contains both satured and unsatured fat acids, even though the first are mainly found in animal lipides.
However, the distinction is quite important because satured fats can increase the level of "bad" cholesterol in blood and help it stick to the artery walls, meanwhile the unsatured ones have a protective effect against arteriosclerosisi (that's why they are called "artery sweepers").

CHOLESTEROL

It is the main casue of arteriosclerosis, but play useful functions too: it is indispensable for the formation of cellular membranes and helps the formation of biliary salts and of some hormones and vitamins. That's why, even in the worst case of cholesterolemy, the American Heart Association, even advising not to adsume more than 200 mg. a day, don't prescribe its elimination.
We must say that the main part of cholesterol is synthesised by sliver that, if in health, is able to correct its temporarily unbalance; obviously an exaggerated assumption of cholesterol can break this frail action-reaction balance.
Blood contains two kinds of cholesterol: the LDL (low-density, called "bad") that sticks to the artery walls obstructing them, and the HDL (high-density, called "good"), that sweeps and destroy the LDL.
The best fat levels in blood are:

Total cholesterol: less than 200 mg / dI
LDL: less than 130 mg / dI
HDL: more than 40 mg / dI
Threeglucides: less than 200 mg / dI

Among the unsatured fats, there are two very important kinds because our organism is unable to product them and must therefore be assumed through alimentation: linoleic acid and a-linolenic one.
Lipides's function are mainly energetic (they have more than twice the kcal amount of carbohydrates and proteins!); in addiction, they help thermic isolation and make possible the absorption of vitamins, so-called liposoluble (A, D, E, K) because can be transported by fats only.
Finally, they rule the hunger center, giving the sensation of satiety and making food more appetizing.
We think it's not necessary to explain the plastic (supporting and filling) function of fats, that is so evident!
Regarding the demonizing of lipides, we would like to say that the 35% of our nervous system (including brain) is composed by lipides.

VITAMINS

They are a group of substances that rule biological process, bacuse they are necessary for starting particular reactions. We need very small quantity of vitamins, but their assumption is indispensable because the most of them are not synthesised by our body.

MINERALS

They are inorganic substances, necessary in very small quantity, but indispensable. In addiction to a plastic role, especially for building bones, teeth and cartilages, they can turn on particular chemical reactions.

A well balanced must contain a right proportion of this nutritive substances:

• 10- 15% of proteins
• 30-35% of lipides
• 50-55% of carbohydrates (10% of simplex sugars assumed trough tah maximum variety of fodds, because the perfect food does not exist, but every food can bring particular substances).

A hypocaloric diet, instead, suitable to lose wight, should be:

• 20% of proteins
• 25% of lipides
• 50-55% di carbohydrates, leaving simplex sugars out.

If we want to establish how many calories should be introduced each day, the situation becomes complex.
A suitable medium amount should be, approximatively 2500 - 2700 kcal a day for men, anche 2000 - 2150 for women.
However, we must consider many variables: first of all, the physiological conditions (e.g. during pregnancy and nursing, alimental needs - especially proteinic need - increase), physical structure (the daily energetic requirements increase with muscular mass), the age (during growth the need for plastic aliments is higher: a child require about 20 gr. of proteins a day, meanwhile a teen-ager 72 gr. and an adulto 62 gr.; in the old age, instead, the energetic need drops of 1/3), the sex (men have a higher proteinic need, due to the more developped muscular mass), the weather (in winter we can assume more lipides for thermic needs, but without exaggering!) and above all the knid of work (hand-workers require much more energy: if we suppose that our energetic consumption per hour relaxing is 100, the consumption rises to 500 if we spend that hour sawing wood).

If we want to establish how many calories we introduce through alimenation, the operation is quite simple, as the energetic content per gram is:

• Glucides: 4 kcal
• Proteins: 4 kcal
• Lipides: 9 kcal
• Alcohol:7 kcal

Now let's see the composition of the main grown mushrooms, in order to understand if they can become part of a health alimentation.