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Nutrition is a very broad term, encompassing all the processes by which a living being acquires the necessary elements to maintain life, with the exception of oxygen and water. While food is the act of taking food.
Thus, nutrition consists of transforming food into nutrients. That is, we take food that after digesting them, absorb them and metabolize them become nutrients, which through the bloodstream reach all the cells of our body.
In higher animals, nutrition comprises several steps, ingestion, chewing, swallowing, digestion, absorption, metabolism and excretion. Stages consisting of physical processes (chewing, swallowing, advancing of the alimentary bolus through the digestive tract), as well as bio-chemicals (which comprise the whole set of chemical transformations that food undergoes until it becomes a useful nutrient for the organism). The chemical transformations are produced by hydrochloric acid and digestive enzymes, such as ptyalin, pancreatic amylase, lipases, proteases, peptidases, intestinal enzymes and the emulsifying effect of bile.
The digestion begins in the mouth with the processes of chewing and salivation. Chewing is essential for grinding food and promoting chemical and enzymatic digestion. The latter begins in the mouth with the salivary amylases (ptyalin), responsible for the first degradation of carbohydrates, particularly starch.
Digestion reduces food to release nutrients, which by the process called absorption will pass to the hepatic portal vein that will lead to the liver; Where they can undergo chemical transformations. In this way, nutrients can be transformed into others to make better use of resources, and ensure the satisfaction of the needs of the body. And finally, the nutrients, carried by the blood, are distributed throughout the body, to meet the needs of all our cells.
The digestive system comprises: mouth, epiglottis, salivary glands, esophagus, stomach, small and large intestine, liver, gallbladder, pancreas.
In short, and in summary, nutrition consists of obtaining from the food we eat the useful substances that our body needs.
But, proper nutrition depends not only on the proper functioning of the digestive system but also on the nervous system. Or perhaps better, we should say of the neuroendocrine system. We can not forget that the autonomic or vegetative nervous system regulates all the functions that are vital. And this is done directly by the innervation of sympathetic and parasympathetic nerves or by combining the autonomic nervous system with the endocrine system. An example of this is the regulatory function of the hypothalamus through the axes: hypothalamus-pituitary-ovarian; Hypothalamus-pituitary-thyroid, hypothalamus-pituitary-adrenal, hypothalamus-pituitary-growth hormone. Axes that regulate the processes of nutrition from the control of the will to eat, to the control of the energy metabolism.
The aroma and color of food stimulate the secretion of saliva, gastric juices and peristalsis, through the parasympathetic system. Emotions such as fear, worry or anger stimulate the hypothalamus that activates the sympathetic nervous system, which in turn depresses secretions and inhibits peristalsis.
And the circle closes as follows: The nervous system regulates the functioning of the digestive system, and in turn the digestive system provides the necessary nutrients for the proper functioning of the nervous system, which is the material basis of our soul and mood .
The nutritional requirements of each individual are different and depend on age, sex, type of activity, whether healthy or suffering from illness …. Therefore, there is no universal diet but must be adapted to the needs of each case.
After giving a brushstroke to the physiological and biochemical aspects of nutrition, I would like to delve into the object of nutrition: nutrients. According to its chemical quality it distinguishes between organic and inorganic nutrients.
The organic nutrients are the macronutrients: carbohydrates, lipids and proteins. While inorganic nutrients are minerals, which depending on the quantities the organism needs are classified into macrominerals (calcium, phosphorus, magnesium, sulfur) and trace elements (iron, zinc, copper, iodine, fluorine, chromium, cobalt, Selenium, manganese, molybdenum).
Our body has the great capacity to transform some organic nutrients into others (action performed mainly by the liver), except for a set of so-called essential nutrients, which are indispensable for life and must necessarily be taken in the diet You have to be careful about restrictive diets). These essential nutrients are: certain amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine), vitamins (A, C, D, E, K, B1, B2, B3, B6, B12, Pantothenic acid, biotin and folic acid), some fatty acids (α-linolenic (18: 3ω-3) and linoleic (18: 2ω-6)). While inorganic nutrients must all be taken in the diet, because our body can not transform one into another.
Yes, indeed, nutrition is the set of physical and biochemical processes necessary to transform food into nutrients. However, to achieve good nutrition is not enough to understand and care for our digestive system; But we must know what and how to eat at each stage of our life. To provide our body with the elements it requires to maintain good health and provide energy to maintain good activity and animosity. Now you can understand the importance of a correct diet to achieve good health.
For thousands of years man is aware of the importance of proper nutrition to achieve proper nutrition. Over time, food has gone from being an instinctive concern (to quench hunger and appetite) to being a conscious concern, in understanding its importance for health. Thus, so many and many schools and doctrines on nutrition have been emerging, from ancient Egypt and ancient China to today. Some of them are intuitive, others philosophical, others religious, others are based on experience and others are based on scientific bases. And while they all share the same goal: to maintain good health; There are serious contradictions between all of them.
SOME OF THE SCHOOLS AND NUTRIENT STREAMS
• Vegetarian vs Omnivorous
• According to Blood Group
• According to the pH
• Diets without:
• without gluten
• Without cow’s milk
• without salt
• Quantum mechanics
• Weight Loss Diets
A comparative analysis of all the nutritional theories and schools that have appeared throughout history and those that still exist today is not possible in this article. But the basic lines of proper nutrition can be indicated.
NUTRITION IN HEALTH:
• Listen to us
• Avoid extreme breaks
The foods we eat make up our diet. What characteristics should a healthy diet meet?
1. The diet chosen should provide the body with all the nutrients it needs for its proper functioning.
2. The choice of food we eat should be made in such a way that we give the least possible amount of toxins. That is to say, it is advisable to choose fresh and natural foods, avoiding to the maximum the industrially produced products, the molds, the refritos and the smoked ones. I recommend going back to the kitchen, and I encourage you to prepare the food from natural products.
3. It is advisable to choose seasonal foods, as they are most suitable to the needs at each season.
4. And I always advise you to flee extreme diets, because in equilibrium you find virtue. Take special care with both restrictive diets and with supplements or fortified foods.
And, choosing the right diet is not enough. Also, pay attention to how to prepare food. It is not the same to take raw foods, boiled, roasted or fried. This apparently so obvious, is not always and is not always taken into account. In general, basic rules are to be followed:
1. Raw and cold foods will be avoided in the fall and winter seasons. And they will not be abused in summer.
2. Fried foods should be taken gently. Avoid frying too much of the temperature so that the oil will not burn. The reuse of the oil must be done prior filtration. The oil will never be reused if it has darkened.
3. Food prepared on the grill and baked are advisable in winter. Well, warm, warm and dry.
Listen to our body. Our body alerts us when we take an unbalanced diet, and sets in motion mechanisms to regain its harmony. So, in the face of excess intake of minerals or vitamins (usually due to the intake of supplements or fortified foods) our body will ask us to eat more protein, fat, carbohydrates and drink more water. While if it is exceeded in proteins, fats and refined sugar our body responds with appetite for salt and other minerals like calcium. If we do not bring it, it will be extracted from another site, causing demineralization. Refined sugars require a higher intake of fats and proteins. And conversely, an excess of protein and fat calls for refined sugars and water. And not only this, but also our mental and physical state as our physical and mental activities may be demanding certain nutrients, which are translated as appetite. Apetencias that should recognize and satisfy, always paying attention so that it does not become an excess or addiction.
In addition to everything said, the environment that surrounds us during the meal affects the digestion process. Let us not forget the direct relationship between the digestive and nervous systems. The atmosphere during the meal has to be quiet and friendly. Tension must be avoided during the meal. To prevent the sympathetic nervous system block or slow down digestive processes.
Also, we must be aware that we are eating. If you eat watching TV or reading our attention you withdraw from the act of eating. We are not aware of what we are eating and in this way our autonomic nervous system does not have the reinforcement of the senses, sight and smell, which activate the functioning of the digestive system by the parasympathetic stimulation. In this way our digestive system is less prepared to perform the digestion. And, to make matters worse, we also lose a basic pleasure of survival: the pleasure of eating, which is one of the basic instinctive pleasures that anchor us to life.
And finally, the schedule. Our body prefers frequency to quantity. That is to say, it prefers that the daily intake is divided in many takes to eat almost all the intake in one or two main meals, leaving long time of fast between them. And, thanks to an hourly routine, since our body has an internal clock that regulates all the vegetative functions, to accommodate the vital functions to both the needs and the contributions.
Just as balanced nutrition is indispensable for good health; In situations of illness, it is necessary to adapt the diet so that the nutrition is appropriate so that it contributes in the healing In this consists the nutritional therapy.
The correct nutrition is indispensable to enjoy good physical and mental health. The basic rules for good nutrition are few and simple, and therefore easy to follow. It is not necessary to lose oneself or to be distressed among so many diets and recommendations that circulate on all sides.
If it is intended to achieve a goal with food, it is advisable to seek the advice of an expert, whether nutritionist, dietitian or bromatologist, to explain the virtues and contraindications of each diet.