Consumed foods fulfill their role in the body through two specific actions. is about:
Consumed foods fulfill their role in the body through two specific actions. is about:
1. the calorific power, which is given by the quality of the food to produce chemical, mechanical and caloric energy by burning them in the body;
2. the specific action of each chemical, for one or more functions of the body.
Proteins, carbohydrates, lipids, vitamins, mineral salts and water are the specific chemicals by which foods perform their functions.
Only proteins, carbohydrates and lipids have calorific power while vitamins and mineral salts act as biocatalysts, contributing to or taking part in the chemical reactions required for metabolism. Water is the dispersion medium in which all these reactions take place.
Proteins, carbohydrates and lipids
The main source of carbohydrates is food of vegetable origin, represented by cereal flour, potato starch, fruit and vegetable sugars. Carbohydrates of animal origin are represented by lactose from milk and glycogen from the liver.
Carbohydrates help in protein synthesis and complete fat burning.
They are very complex organic substances, made up of a variable number of amino acids.
Proteins of high quality, containing all the amino acids necessary for the body we find in foods from the animal kingdom: eggs, meat, fish.
Foods from the vegetable kingdom that contain amino acids are: dried legumes (peas, beans), soy, wheat, corn, some fruits.
The role of proteins is to provide the body with the material needed for recovery and growth.
Fats or fats are both animal origin (pork, butter, lard, sole) as well as vegetable (oils, margarine). The main role of lipids in the body is that of energy source.
Animal fats contain especially vitamins A, D, E and vegetable fats contain mostly unsaturated fatty acids, indispensable to the body.
For a good use of fats, the body must have a balance between fat and carbohydrates (the latter helps to burn fat). The optimum proportion is one part fat for two carbohydrates.
The body can store large amounts of lipids in adipose tissue, from excess carbohydrates and dietary fats.
Vitamins play an indispensable role in the proper functioning of the body, helping to achieve the most enzymatic and oxidative reduction reactions. Their lack or insufficiency can cause specific disorders related to certain functions of the body, such as signs of rickets (in case of insufficiency or lack of vitamin D) or of xerophthalmia - drying of the cornea - and disorders of skin trophicity (in case of vitamin A). . Their categorization into lipid-soluble and water-soluble has the advantage of indicating the sources in which they are found. Due to the versatility and variety of their effects, they were assigned alphabet letters and even became used as therapeutic factors (medicines) in the treatment of many diseases. The need for vitamins is proportionally higher in children, although a balanced and rational diet under normal environmental conditions can ensure the necessary functioning of the body. It has been shown that drug abuse of vitamins is dangerous and can lead to toxic conditions in the event of administration of large doses of vitamins or polyvitamins. Therefore, it is preferable that their transfer to the body is done through the foods that contain them, which contributes to a more efficient assimilation.
Sources of vitamins
Although the human body can synthesize a number of vitamins, such as vitamin D (in the skin, under the action of ultraviolet rays), vitamin K and some of the B complex (in the intestine), the amount it synthesizes is extremely low. Thus, the main source of vitamins is food.
An important role in the growth and development of children is played by fat-soluble vitamins (vitamin A, vitamin D and vitamin K) and water-soluble vitamins (complex B, vitamin C).
Vitamin A plays an anti-infectious role, protecting the mucous membranes and skin, increasing and retinal purple formation. Its lack or insufficiency can lead to xerophthalmia (drying of the cornea), hemeralopia (difficulty in accommodating the vision in the twilight) or to diminish the appetite and the growth rate. Vitamin A needs must be provided, in equal parts, from the animal kingdom as well as from the vegetable kingdom. Foods of animal origin contain a very high level of vitamin A (butter, liver, meat, eggs, fish lard, etc.), while in foods of vegetable origin it is found in the form of provitamin (carotene) in carrots, tomatoes , cabbage, cauliflower, parsley, green beans, etc.
Do not use medicinal preparations based on vitamin A unless prescribed, as there is a risk of acute chronic poisoning.
Vitamin D, also called antirheitic, is vital in the metabolism of calcium and phosphorus and in the process of bone formation in growth (osteogenesis). It is synthesized by the body by transforming the provitamin D (ergosterol) in the skin under the influence of ultraviolet, solar or artificial rays, but it cannot be counted too much on this contribution given the climatic and environmental conditions (pollution, dust, smoke, fog, etc.). The source of vitamin D in the diet is low, being found in small quantities in butter, milk, egg yolk. Fish liver oil contains large quantities, but it is not used as food, but rather as a medicine. Because the newborn cannot accumulate reserves of vitamin D due to the almost non-existent exposure to the sun, it is necessary to prophylaxis rickets from the first two weeks of life. This should continue during the first year of life, either in the form of drops administered daily (1000 µl / day), the number of drops depending on the concentration of the preparation, or in the injectable form (200,000 µl) at 7-14 days after birth, the dose which will continue to repeat from 2 to 2 months, until the age of one year. After the first year, the prophylactic treatment of rickets will be done as needed, at the doctor's suggestion.
Vitamin D is the only recommended vitamin in the form of medication right from birth. The correct and obvious administration of this fact are very useful, because an overdose of vitamin D can prove dangerous, especially in the case of administration in high doses, by injection.
Vitamin K is also called anti-hemorrhagic vitamin, indicating its role in blood coagulation. Foods of vegetable origin (cereals, roots, carrots, beets, potatoes, tomatoes, cabbage, cauliflower, spinach, etc.) represent a more predominant source of vitamin K than those of animal origin (egg, beef and pork liver). It can also form in the intestine, being synthesized by the microorganisms existing here (by colibacilli in particular). Food intake plus synthesis in the intestine generally covers the need for vitamin K in the body.
Vitamins belonging to group B include very different chemicals: vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B6 (pyridoxine), vitamin B12 (cobalamin), folic acid, vitamin PP (nicotinic acid), acid paraaminobenzoic (vitamin H1). These vitamins participate in the activity of some enzymes, without which some synthesis and processes at the cellular level could not take place. Each of them has certain peculiarities, which makes the deficiency signs have specific characteristics. Under normal feeding and care conditions these deficiencies are rarely encountered. Medication supplementation is done only at the doctor's suggestion. Some B vitamins play an important role in hematopoiesis (red blood cell formation), especially folic acid and vitamin B12. Vitamin B sources are found in both animal foods (milk and milk derivatives, especially yogurt and health, meat, liver and eggs), as well as those of vegetable origin (cereals, yeast). Vitamin C (ascorbic acid) is the most widespread vitamin in nature, especially in foods of vegetable origin - fruits (lemons, oranges, apples, peaches, apricots, macaroni, currants) and vegetables (tomatoes, carrots, peppers). Almost all vegetables contain this vitamin. In foods of animal origin are found in liver, meat, egg yolk, milk, etc. Because it is sensitive to the action of heat and oxidation, the preservation and technical processing of foods leads to high losses of vitamin C. The role of this vitamin in the body is to regulate the cellular metabolism, to strengthen the defense capacity of the cells against infections, to prevent bleeding. Vitamin C requirement varies with age and general condition, but on average, it is estimated to be 50-100 mg / day.
In the human body almost all the chemical elements of nature are found, only that they are degraded during the metabolic processes and eliminated as waste through the urine, by digestive or cutaneous route. To replace them, they must be brought through food. The main minerals necessary for a good functioning of the body are: sodium, potassium, chlorine, calcium, phosphorus, magnesium, iron, iodine, fluorine, copper, sulfur, cobalt, lithium. Some are needed in very small quantities, "traces", such as: iodine, fluorine, magnesium, and others in measurable quantities in grams: chlorine, sodium, calcium, phosphorus. Mineral substances are found both in foods of vegetable origin (sodium, chlorine, potassium, iron), as well as those of animal origin (calcium and phosphorus - in milk and milk derivatives, iron - in liver and meat, fluorine - in fish ). In the body, mineral substances are, in well-defined proportions, in certain tissues and moods (intercellular fluid, lymph and blood). Maintaining these proportions is one of the most important premises of the good functioning of the body. Some mineral substances also take part in the structure of the body, so calcium and phosphorus take part in the formation of bone tissue, iron enters the constitution of red blood cells.
The need for mineral substances is proportionally higher in children than in adults, given their use in the growth process. Thus, for every gram of synthesized protein substance, a quantity of mineral substance is required. The need for mineral substances, even in children, under proper health and nutrition, is provided through food. It is not necessary to choose foods rich in certain minerals, but to ensure, through the food ratio, a stable balance between all the nutritional principles. The absorption and use of mineral substances by the body depends on their proportion to vitamins and other nutritional principles (proteins, fats, carbohydrates).
Water is the most important source of iodine, fluorine, lithium, cobalt.
The waterOne of the indispensable elements of life is water. It is the main support of all cellular exchanges and is found in the body in the form of complex hydroelectrolytic solutions. The water requirement differs greatly depending on the age. Thus, per kilogram of body weight, in 24 hours, it is necessary to:
- baby, 150-200 ml of water
- the child from 1 to 3 years, from 100-200 ml
- the child from 3 to 6 years, from 90-100 ml
- the child from 6 to 12 years, 70-80 ml
- the child, from 12 to 15 years, 50-60 ml
- adult, 35-40 ml.
Water needs increase in the case of disease, especially fever, as it is lost through accelerated breathing and sweating. In children, water metabolism is especially labile, especially in the sense of water loss, in which case dehydration occurs. Water sources are food and, of course, drinking water. In the case of drinking water, you must pay greater attention to the hygienic conditions of the sources from which it comes (for example, fountains in the rural area). There is the possibility of waterborne transmission of pathogenic microbes (typhoid fever microbes, salmonellosis, epidemic hepatitis virus, viruses of other diseases) as well as chemical poisoning with nitrites (decomposition products of organic substances found in water). This intoxication usually occurs in infants and is manifested by cyanosis (aging of the whole body) and altered general condition. The first measure is to stop the use of contaminated water and to present the child to the doctor.
Classification of foods by product categories
Category I: Milk and cheese
This group includes all forms of dairy products (liquid milk, powdered milk, sour milk, whipped milk, yogurt, ketchup, simple and fermented cheeses), with the exception of cream and butter which, from a nutritional point of view, falls into the fat category. . We will focus more on this group, because milk and its derivatives occupy a prime place in the feeding of the infant and a significant place for the other age groups ((30-35% of the caloric value of the ratio of children up to 4). -5 years, 18-20% over this age).
The most commonly used, in milk-based nutrition, is cow's milk and, more rarely, sheep's, goat's or buffalo's milk. The content in nutritional principles varies according to the species from which it comes, and in the same species it varies in relation to the lactation period, the feeding of the cattle, climate, etc. The most important variations exist in terms of fat. Milk contains, in varying proportions, all the nutritional principles, so it is a balanced food, which makes it possible to feed the baby up to 4 months with milk only. Milk proteins are high quality proteins, containing all the essential amino acids in optimal proportions. They are easily digestible and have a great power of forming new tissues during the growth period.
Except for protein intake, milk and cheese are the most important source of calcium. The amount of calcium in cow's milk varies around 125 mg%, and that of cheese can vary from 150-160 mg% in cow cheese, up to 900-1200 mg% in hard cheeses from sheep's milk. In acidification precipitation (how to prepare cow cheese) most of the calcium passes into whey in the form of milk. That is why it is good for whey to be used in broths, or drink as such. In coagulation, through the labferment (clot) casein retains all the calcium with which it is combined. The calcium / phosphorus ratio (125 mg% / 91 mg%) in cow's milk is superunitary (1.4), approaching the one existing in the bones; in breast milk the ratio is 1.9-2, being optimal for good mineralization. These elements are found next to the natural vitamin D (calciferol) which, although found in small quantities (3-4 ounces in milk, 20-40 ounces in fatty or very fatty cheeses), is the most active form and, being dispersed, it has great mineralizing effect. Milk is rich in vitamin A (retinol) containing 150 µi%. This vitamin, being fat-soluble, is removed by scavenging (degreasing). It contains about 2 mg% of vitamin C, which is lost through boiling and prolonged storage. The vitamins in group B (B1, B2, B6, B12) are present in small quantities. Naturally acidified dairy products, through the action of bacteria and acidophilic yeasts, increase the milk content in these vitamins. The caloric value for whole milk is 65-70 cal / 100 g and for cow cheese it is 100 cal / 100 g. Fat and very fat cheeses can reach 300-400 cal / 100 g. By removing the cream, the caloric value is shrinks, so it is recommended that the milk be mixed during boiling.
Digestion of milk
Because it is the element with the least digestive effort, milk is the ideal food for children, for pregnant women, for the majority of patients and for those who work in toxic environments. In a proper diet, the milk and cheese group should be at 25-30% of the caloric value of the ratio of children between 1 and 6 years old, at about 20% of the caloric value for women during the maternity period (pregnancy and lactation), between 12-16% of the ratio for adolescents and adults working in toxic environment and 5-10% of the ratio for the other categories of the population. The use of acidified preparations is even more advantageous (whipped milk, acidophilus, yogurt), because it increases the amount of vitamins in group B and the possibilities of absorption of calcium salts. No other natural element has such a wide range of uses and possibilities of association. Maintaining an extended lactopain diet, such as milk grains in children, causes the appearance of iron deficiency anemia (due to iron deficiency). The milk is low in iron, copper, magnesium and has a low calorific value. The cheeses are practically devoid of vitamin C and carbohydrates, however they are rich in sodium (especially the salty ones) and poor in potassium. Salted cheeses are contraindicated in conditions with a tendency to sodium and water retention (edema).
Category a: Meat and fish
This category contains all food of animal origin, regardless of species and how they are obtained (cutting, hunting, fishing). Due to the great diversity of species and the varied range of industrially processed products, the content in nutritional principles, the degree of digestibility and use in the body are different. Foods in this category are closer to the composition of the human body and have a very high nutritional value. They are rich in high quality proteins (essential amino acids). The caloric value depends mainly on the fat content, which is variable in relation to the species from which they come, with the anatomical parts, and depending on how weak or fat the animal was at the time of slaughter. Meat, but especially viscera, is the most important source of iron (3-5 mg% in meat, 10-14 mg% in liver) and phosphorus (200-350 mg%). Significant quantities of B vitamins are found in meat and fish. Fish is the richest food in iodine and fluoride. In contrast to the uniformity of the composition of meat in amino acids, the content of vitamins is variable, depending on the species and nature of the meat, the fat being poorer in vitamins. Pork is rich in vitamin Bi (thiamine). Viscers and especially the liver are the richest in vitamins and mineral salts. Vitamins A and D are found mainly in fatty fish. By preparation, the meat keeps vitamins A and D (sausages, smoked meat.).
The meat and its derivatives cause a very abundant digestive secretion (gastric and pancreatic). Due to its sensory properties, meat is a food that likes, with great saturation power, the digestive secretion of psychic nature being a very good one. The use of meat proteins is very good, and for lipids it varies with the species from which they come and is absorbed the harder they are, the more abundant they are.
The meat enters the child's diet from the second half of the first year of life, through the soup and the meat puree (10-20 g beef or boiled poultry along with the vegetables). At the end of the first year you can reach 30-50 g of boiled beef, beef or poultry, added to various preparations. One day a week it is good to replace the meat with the liver from the menu. Frozen meat retains its nutritional properties and vitamins.
Meat ratio by age groups:
- between 1 and 6 years, 60-80g ((4-5% of the caloric value of the ratio)
- between 7 and 12 years, 120-140 g (6-7% of the caloric value of the ratio)
- adults 150-250 g (6-7% of the caloric value of the ratio)
- pregnant women 150-200 g (6% of the caloric value of the ratio)
Category a lll-a: Ouale
Egg contains the proteins with the highest nutritional value, especially its yolk. The yolk is 20-30 times richer in vitamins and minerals than blue. It is rich in vitamins A, D, K, vitamins in group B (B1, B2, folic acid and B12) and minerals: phosphorus 200-250. mg%, iron 3-5 mg%, calcium 60 mg%. The digestion of the egg depends largely on how it was prepared. The yolk is easier to digest than the blue, having a reduced excretory effect. Because it is completely absorbed, it is a food that can be given to children from the age of 5 months. The disadvantage of the egg is that it can produce allergic phenomena. It is advisable to give infants only the yolk, because the albino is most often responsible for allergic reactions. Only chicken eggs are recommended for children.
Category IV: Vegetables and fruits
Of this category belong almost all foods of vegetable origin rich in water. The edible part, in the composition of the plant, varies according to the species from which it comes. Thus, the roots, bulb, stem, leaves, flowers, seeds or the whole plant can be consumed. Vegetables and fruits are divided, according to the structure, into different species, but through the common characteristics of the composition in nutritional principles they can be replaced with each other:
- fruits with seeds: apples, pears, peas, citrus fruits, oranges, lemons
- fruits with seeds: plums, cherries, cherries, apricots, etc
- berries: grapes, citrus fruits, currants, blackberries, figs.
Despite these varieties of form and content, all are rich in water (72-95%) and contain indigestible material (cellulose, pectin). Apart from these macro-elements, in the composition of vegetables and fruits, numerous mineral elements and vitamins, flavors, ethereal oils, pigments are included.
Fruits and vegetables are the most important source of carbohydrates. Except for potatoes, in which the carbohydrates are in the form of starch, in all the others they are represented by sugars (fructose, glucose, sucrose). They contain a small amount of proteins, which are found mainly in beans, peas, onions, but they are incomplete proteins. Fruits and vegetables are rich in vitamins and mineral salts, vitamin C found in all fruits and vegetables. It is lost through storage and processing, but fruits and vegetables, being foods that are consumed raw, remain the most important source of vitamin C. In fruits and vegetables, vitamin C is lost through storage and dressing. The acidity increases the resistance of the ascorbic acid to the action of oxygen, which is why vitamin C is better stored in acidic fruits. On average, 90-95% of the needs for this vitamin are covered by foods in this group.
Vitamin A, in the form of provitamin, is found in both green leafy vegetables and red vegetables (carrots, carrots, beets, tomatoes, asparagus, radishes). It is not lost through storage and processing.
Vitamins from group B (B1, B2, B6), vitamins PP and P are also present in fruits and vegetables, with 20% of the body's needs being covered in this way. Through cellulose and pectin content, vegetables and fruits play a role in normalizing intestinal transit, fighting constipation and diarrhea. This represents the dietary basis of the use of carrot soup and apple paste in diarrhea and combating constipation through a diet of vegetables and fruits rich in cellulose.
Category V: The derivatives of cereals, dried vegetables and oleaginous fruits
This category includes cereals (wheat, rice, rye, oats, corn, millet), legumes (through beans, peas, lentils, soy, peanuts) and oily fruits (nuts and nuts). This category, represented especially by seeds (nutritional reserve necessary for germination of the plant embryo), can provide, in small volume, large quantities of nutritional principles. Unlike legumes - beans and lentils, which can be found on the food market as such, requiring only thermal processing - cereals are subjected to industrial processing consisting of husking, grinding, baking. The results of these industrial processes come into our kitchens: husked rice, rice or wheat, rice, wheat flour, rye, rice, malai or corn flour, corn flakes, rice, oats, bread.
The basic nutritional principle of cereals is carbohydrates, through starch, which appears in proportion of 42-46% in whole grain bread and 80% in gray. The protein content is low, 7-16% in cereal foods, 20-26% in those of dried legumes, and the nutritional value of the vegetable proteins is less balanced (they do not contain all the amino acids necessary for the body).
Soybean is the element with the highest protein content, having the most balanced and most assimilable form.
Bread is the main exponent of this group, representing, on average, 20-50% of the adult caloric ratio and 80% of the carbohydrate consumption. In children, the bread enters the diet from the second semester of life, at 5-6 months, in the form of bread crumbs boiled in milk or mixed with juice and fruit pulp. The dietary ratio of bread to children is 25-30 g per year from 1-3 years, during a day, the rest of carbohydrates being represented by grays, flour, rice, 150-200 g per day between 3 and 6 years, 200-300 g between 7 and 14 years, 300-450 g over 14 years. White bread is easier to digest, but contains fewer nutritional principles, protein substances, vitamins and salts that are lost through husking and refining.
Mamaliga, a food that is part of our national tradition, contains little nutritional protein and is completely devoid of vitamins. Associated with products of animal origin, such as milk, cheese, eggs, it becomes a nutritious food.
Category VI: Sugar products
This category contains industrial products, with a high calorific value in a small volume, represented by small molecule carbohydrates. Sugar is the most important element of this category. When consumed alone, in moderate quantities, sugary products are easily digestible, with minimal digestive secretion. It is recommended to those who practice sports, during periods of physical exertion. The excess of sweets, especially in children, leads to unhealthy eating habits, tooth decay and obesity. That is why, in the case of children, dry cakes are recommended at home. Due to the feeling of satiety it is preferable that they be served as dessert at the end of meals.
Category Vll-a: Lipids
They are found both in foods of plant origin and in those of animal origin. Vegetable fats are represented by plant oils, sunflower, olive, pumpkin, soy, corn germ, coconut. Animal fats are: butter, lard, poultry lard, sole, fish lard. Margarines are mixed fats (vegetables and animals), industrially prepared with added flavors and vitamins. Fats have a caloric value of between 700 and 925 calories per 100 g, so in a small volume contain a high caloric value. They represent 30-35% of the caloric value of the food ratio. They are recommended for those with intense activities that require high energy consumption.
Although most fats do not include other nutritional principles, butter contains vitamin A (tretinol) and vitamin D (tcalciferol). Vegetable fats contain unsaturated fatty acids (linoleic, linolenic, arachidonic), necessary for the proper functioning of the body. The influence of food fats on blood lipemia and cholesterol depends on the presence of the fatty acids they contain. Fats are used in most culinary preparations due in particular to their quality to form emulsions. This does not impair its nutritional qualities if the boiling point does not exceed the fat melting point.