Need for essential amino acids

«Essential amino acids: introduction

Essential amino acids and their main sources of plant origin Amino acid Vegetable origin Phenylalanine Wheat germ Isoleucine Scarce sources available Histidine Wheat germ Leucine Wheat germ Lysine Various legumes Methionine Seeds in general, sunflower seeds, nuts Threonine Legumes, only marginally cereals Tryptophan Almonds, low in legumes and cereals Valina Wheat germ

The daily requirement of essential amino acids is expressed in mg / kg / day and varies according to the age of the subject and his state of health.
To meet this requirement it is almost always sufficient to take one gram of protein per kg of body weight per day (corresponding to about 10% of the total energy). Specific deficiencies can arise only in the presence of certain pathological conditions, eating disorders or habits improper dietetics (vegan, fruitist, raw food diet, etc.) continued for long periods of time.

Another limiting factor, often underestimated, is the total caloric intake: if the diet is highly hypocaloric, most of the amino acids are in fact used to produce energy and the nitrogen balance can become negative.
Children and athletes need more protein than the rest of the population. However, the increased need can be met simply by increasing the overall caloric intake.
The same can be said for nurses or pregnant women where proteins, given their plastic function, are of fundamental importance.

To get adequate amounts of essential amino acids, most nutritionists recommend consuming an amount of protein equal to:

10-20% of the daily caloric intake (one gram of protein equals 4 Kcal or 17 Kjoule) or 1-1.5 grams per kg of body weight *

* when calculating the daily protein requirement, the desired body weight (ideal weight) is considered and not the actual body weight. In the newborn this requirement rises up to 2.2 grams per kg. In athletes and in the growth phase, a protein intake close to the upper limit (1.5 g / kg) is more suitable, while for sedentary patients a "intake" may be sufficient. of 0.8-1 grams of protein per kg.

An integration of essential amino acids can possibly be justified for:

marathon runners
body Builders
vegetarians
subjects who follow a "diet poor in meat, eggs and fish
subjects who for work reasons or professional sporting activities are unable to support complete main meals adequate to the daily protein requirement

Requirements for essential amino acids in adults (FAO Committee 1973): values ​​in mg / kg / day Histidine (8-12)* Isoleucine 10 Leucine 14 Lysine 12 Methionine + cystine 13 Phenylalanine + tyrosine 14 threonine 7 tryptophan 3,5 valine 10 total essential amino acids 84 * The FAO Committee report did not indicate values ​​for histidine. Currently, there is evidence that this amino acid is essential not only for the newborn, but also for the adult. The values ​​of the requirement are estimated between 8 and 12 mg / kg / day.