Nutrition is the science that studies the effect of food in the body

The word «nutrition» refers, in its most traditional sense, to the process through which the body separates food to obtain substances (named «nutrients») that it will use for numerous functions. That process consists principally of three phases: digestion (separation of food into nutrients), absorption (passage of nutrients from the digestive tract into the blood) and transport (move of nutrients, through blood, to the place where they will have an effect).

But the word «nutrition» refers, in its most correct sense, to the science that studies that process more broadly (from food outside the body, to its last effect in it after ingesting it) and everything that has a certain relationship with it. Nutrition is an extremely complex science, that interacts with other sciences and numerous factors. It can be considered a new science (because it began to be investigated more thoroughly, relatively recently) about which there is still much to investigate, and about which population (in general) has much ignorance.

The effect of food in the body, depends on a lot of causes, and can be positive or negative. Those consequences tend to be multifactorial and noticeable in the long term, so (added to the ignorance of population, in general) it is not usually given (to nutrition) the importance that it deserves. Due to the different effect depending on what is ingested, how it is ingested, when it is ingested,… feeding should not be random, but systematic and personalized.

El cuerpo es un sistema eficiente y adaptable

Debido a la dificultad para la supervivencia, sobre todo en el pasado, y a numerosos años de evolución, el cuerpo humano es una “máquina” casi perfecta, capaz de utilizar pocos recursos para conseguir grandes resultados, para adaptarse a las circunstancias con el principal objetivo de sobrevivir:

a) Aprovecha la energía al máximo: gasta la mínima y guarda la que sobra como tejido adiposo (grasa corporal). La energía es el principal recurso para la supervivencia, por lo que perder grasa es muy difícil.

b) No crea ni mantiene tejidos, sino los elimina, si no son necesarios. El tejido muscular es muy costoso energéticamente, por lo que ganar músculo es muy difícil también.

c) Se adapta a las circunstancias: a la edad, composición corporal, ingesta, actividad física, radiación solar, temperatura ambiental, cantidad de oxígeno en el aire, etc.

d) Metaboliza (transforma) o excreta (expulsa por la orina) sustancias perjudiciales, innecesarias,… o nutrientes que en exceso lo son.

e) Repara o mejora órganos, tejidos, etc.

f) Produce señales como hambre, dolor, sueño, frío, calor, miedo, ira,… para dar lugar a una acción que lo proteja.

g) Se defiende de infecciones u otras enfermedades: el sistema inmunológico (las defensas del cuerpo) ataca a los agentes perjudiciales (por ejemplo, microorganismos como bacterias o virus), la fiebre los mata al aumentar la temperatura corporal,… la mucosidad, el estornudo o la tos los expulsan de las vías respiratorias, la diarrea los expulsa del intestino, etc.

The body is an efficient and adaptable system

Due to the difficulty for survival, especially in the past, and numerous years of evolution, the human body is an almost perfect “machine”, able to use few resources to get great results, to adapt to the circumstances with the main objective of survive:

a) It takes advantage of energy to the maximum: it spends the minimum and saves the excess as adipose tissue (body fat). Energy is the main resource for survival, so losing fat is very difficult.

b) It does not create nor maintain tissues, but eliminate them, if they are not necessary. Muscle tissue is very expensive energetically, so gaining muscle is very difficult too.

c) It adapts to the circumstances: to the age, body composition, intake, physical activity, solar radiation, environmental temperature, amount of oxygen in the air, etc.

d) It metabolizes (transforms) or excretes (eliminates by the urine) harmful, unnecessary,… substances, or nutrients that are in excess.

e) It repairs or improves organs, tissues, etc.

f) It produces signs such as hunger, pain, sleep, cold, heat, fear, anger,… to give rise to an action that protects it.

g) It defends itself from infections or other diseases: the immune system (the body’s defenses) attacks harmful agents (for example, microorganisms such as bacteria or viruses), fever kills them by increasing the body temperature,… mucus, sneezing or coughing expel them from the respiratory tract, diarrhea expels them from the intestine, etc.

Categorías

/