Nutrients that can not synthesize the organism and must therefore gain from the diet are called essential. These include:
The nutritional sciences deal with the food and its relationship to health. Nutrients are chemical components of food, the body uses for growth, the maintenance of vital functions and energy production. Nutrients that can not synthesize the organism and must therefore gain from the diet are called essential. These include: Vitamins Minerals Some amino acids Some fatty acids nutrients that can build up from food components of the body, are not essential, although its production is made possible by the food. Macronutrients needed by the body in relatively large amounts, micronutrients to a minimal extent. The lack of nutrients can lead to malnutrition, the lack syndromes (such. As kwashiorkor, pellagra) can cause. An excessive supply of macronutrients leads to obesity and related diseases; the excessive intake of micronutrients can be toxic. Also the balance of different types of nutrients, such as the proportion of unsaturated vs. saturated fat, can affect the development of diseases. Macronutrients macronutrients make up the largest part of the food components and provide both energy and many essential nutrients. Carbohydrates, proteins, including essential amino acids, fats, including essential fatty acids, macro minerals and water are among the macronutrients. Carbohydrates, fats and proteins are interchangeable energy sources; thereby provide fats 9 kcal / g (37.8 kJ / g), proteins and carbohydrates each of 4 kcal / g (16.8 kJ / g). Carbohydrates dietary carbohydrates are broken down into glucose and other monosaccharides. Carbohydrates raise blood sugar levels and provide energy. Simple carbohydrates are made up of small molecules such as monosaccharides or disaccharides together that raise blood sugar levels quickly. Complex carbohydrates are composed of several molecules. They are split into monosaccharides. They raise blood sugar levels more slowly, but for a longer period. Glucose and sucrose are simple, starches and fiber complex carbohydrates. The glycemic index indicates how fast the carbohydrate intake increases plasma glucose levels. Values ??range from 1, the slowest increase, to 100, the fastest increase, corresponding to the supply of pure glucose (see table: Glycemic Index of some foods). However, the increase in blood glucose levels also depends on what foods are added to the carbohydrates. Glycemic Index of some foods category Food Index * Beans kidney beans 33 27 Red lentils soybean 14 Pumpernickel bread 49 69 white bread wholemeal bread cereals 72 Various brans cornflakes 54 83 53 Rolled oats Puffed 90 Weizenschrot 70 dairy milk, ice cream, yogurt 34-38 fruits apple banana 38 61 Orange 43 Orange 49 Strawberry 32 grain barley 22 Brown rice 66 White rice noodles 72 – 38 potatoes Instant mashed potatoes (white) 86 Mashed potatoes (white) 72 50 sweet potatoes snacks corn flakes 72 oatcakes 57 potato chips 56 fructose sugar 22 Glucose 100 Honey 91 Refined sugar 64 * Values ??may vary. The intake of carbohydrates with high glycemic index increases the plasma glucose levels rapidly to a considerable level. It is believed that increases as a result of insulin, causing hypoglycemia and hunger. As a result many calories are added frequently excessive, which can lead to weight gain. with a low glycemic index, plasma glucose levels increase slowly carbohydrates, the postprandial insulin levels remain low, and the feeling of hunger is less pronounced. Thus the consumption of unnecessary calories is less likely to develop lipid levels ultimately advantageous, and the risk for obesity, diabetes and complications of pre-existing diabetes decreases. Proteins Proteins are split from the food into peptides and amino acids. They are necessary for the maintenance, replacement, function and growth of body tissue. However, the body does not get enough calories from food sources or tissue depots, consisting mainly of fat, such protein is used for energy production. Since the body uses dietary protein for the production of body tissue, there is a net gain of protein, thus a positive nitrogen balance. Catabolic body states as such. As present in hunger, infections or burns usually require more protein than is absorbed because the body breaks down tissue. Therefore, a net loss in these cases arises nitrogen balance is negative. Nitrogen balance can be determined best when the excreted in the urine or stool nitrogen is withdrawn from the consumed amount of nitrogen. Nine of the 20 amino acids are essential, d. h., a person can not synthesize them, but must be taken in with food. All people need eight essential amino acids, infants and young children also need histidine. The related to body weight Protein requirements equivalent to the rate of growth that continues into adulthood steadily decreases from infancy. The daily protein requirement is reduced from 2.2 g / kg in infants aged 3 months to 1.2 g / kg for 5-year-olds and 0.8 g / kg in adults. The protein requirements meet the needs of essential amino acids (see table need for essential amino acids in mg / kg body weight). Adults who want to increase their muscle mass, need also very little additional protein beyond the requirements in the table. The composition of the proteins from the individual amino acids is very different. The biological value (biological value, BV) reflects the similarity in composition of the amino acids of the protein to the resist of animal tissues; so shows the biological value, what percentage of a dietary protein provides essential amino acids to the body. With a value of 100, the protein of chicken eggs perfectly matches with the human protein. Animal proteins in milk and meat have a high BV (~ 90). Proteins in cereals and vegetables have a lower BV (~ 40) Some derived proteins (such as gelatin), a BV of 0. The degree to provide in the food proteins, the missing amino acids of another protein, and thus are complementary with this determined total of the biological value of food. Values ??for the recommended nutrient intake (Recommended Daily Allowances, RDA) of protein based on the assumption that the average food supply has a biological value of 70th Need for essential amino acids in mg / kg body weight requirements Infant (4-6 months) children (10-12 years old) adult histidine 29 – – Isoleucine 88 28 10 Leucine 44 14 150 Lysine 99 49 12 methionine and cystine 72 24 13 phenylalanine and tyrosine 120 24 14 threonine 74 30 tryptophan 7 19 4 3 93 28 13 valine required total (without histidine) 715 231 86 Fats Fats are split into fatty acids and glycerol. They are used for the growth of body tissue and hormone production needed. Saturated fatty acids found in animal fats, are more solid at room temperature. With the exception of palm and coconut oil vegetable fats are at room temperature usually a liquid consistency; it abundantly simply contain unsaturated or polyunsaturated fatty acids. The partial hydrogenation of unsaturated fatty acids (such as food production usual) produces trans fatty acids that are solid at room temperature or semi-solid. The main dietary source of trans fats in the US are partially hydrogenated vegetable oils, such as in the production of certain foods (eg. As cookies, crackers, chips) are used to extend the shelf life. Trans fatty acids increase LDL cholesterol and lower HDL levels. Regardless, they also increase the risk of coronary heart disease. Essential fatty acids (EFAs) are linoleic acid, an omega-6 (n-6) fatty acid linoleic acid, an omega-3 (n-3) fatty acid The body requires more omega-6 fatty acids such. As arachidonic acid and omega-3 fatty acids such. As eicosapentaenoic acid and docosahexaenoic acid, which he synthesized from the essential fatty acids. Essential fatty acids (lack of essential fatty acids) are used for the production of eicosanoids (biologically active lipids), for example. As prostaglandins, thromboxanes, prostacyclins and leukotrienes needed. The intake of omega-3 fatty acids reduced according to the current state of knowledge, the risk for coronary artery occlusion. The need for essential fatty acids depends on the age of a person. Adults should take linoleic acid in an amount of min. 2% of the total calorie intake, linolenic acid in amounts of at least 0.5% of the caloric needs. Vegetable oils contain linoleic and linolenic acid. Oils derived from thistles, sunflowers, corn, soy, primrose, pumpkin seeds and wheat germ provide plenty of linoleic acid. Marine fish oil and flaxseed, pumpkin seed oil, soybean oil and rapeseed oil contain a lot of linolenic acid. Oil from marine fish also provides Omega-3 fatty acids available. Macro minerals sodium, chloride, potassium, calcium, phosphate and magnesium are required (see table in larger quantities per day: macro minerals, reference values ??for the supply * of some macronutrients, “Food and Nutrition Board, Institute of Medicine of the National Academies” and recommendations for daily mineral intake). Macro minerals nutrient main sources functions calcium milk and dairy products, meat, fish, eggs, grains, beans, fruits, vegetables bone and tooth formation, blood clotting, nerve transmission, muscle contraction, cardiac conduction chloride Many foods, especially animal products, but also some vegetables; similar to sodium acid-base balance intracellular and blood, osmotic pressure, renal potassium Many foods, including whole and skimmed milk, bananas, prunes, raisins and meat muscle contraction, nerve transmission, intracellular acid-base balance, water retention magnesium leafy vegetables, nuts, cereals, grains, seafood bone and tooth formation, nerve conduction, muscle contraction, enzyme activation sodium Many foods, including beef, pork, S ardinen, cheese, green olives, corn bread, potato chips and sauerkraut acid-base balance intracellular and blood, osmotic pressure, muscle contraction, nerve transmission, maintaining Zellmembrangradienten phosphorus milk, cheese, meat, poultry, fish, grains, nuts, legumes bone and tooth formation, acid-base balance of the blood and intracellularly, energy reference values ??for the supply * of some macronutrients, “Food and Nutrition Board, Institute of Medicine of the National Academies’ category Age or period of time (years) Protein (g / kg) Energy (kcal / kg) Calcium (mg / kg) of phosphorus (mg / kg) magnesium (mg / kg) Infants 0.0-0.5 2.2 108.3 50.0 6.7 1.6 94.4 0.5-1.0 66.7 66.7 55.6 6.7 Children 1-3 1.2 100.0 61.5 61.5 6.2 4-6 1.2 90.0 40.0 40.0 6.0 7-10 1.0 71.4 28 6 28.6 6.1 Men 11-14 1.0 55.6 26.7 26.7 6.0 15-18 0.9 45.5 18.2 18.2 6.1 19-24 0.8 40.3 16 , 7 16.7 4.9 25-50 0.8 36.7 10.1 10.1 4.4 51+ 0.8 29.9 10.4 10.4 4.5 1.0 Women 11-14 47 8 26.1 26.1 6.1 15-18 0.8 40.0 21.8 21.8 5.5 19-24 0.8 37.9 20.7 20.7 4.8 25-50 0.8 34, 9 12.7 12.7 4.4 51+ 0.8 29.2 12.3 12.3 4.3 Pregnant – 0.9 4.6 18.5 18.5 4.9 1.0 7.9 lactating 1 year 19.0 19.0 5.4 * These values ??expressed as average daily intake over time, stand for individual variations in most healthy people who live in the US under the usual environmental impacts. Water is considered macronutrient because it is required in amounts of 1 ml / kcal (0.24 mL / kJ) of energy consumed or about 2500 ml / day. Requirements vary with fever, physical activity and changes in terms of climate and humidity. Micronutrients Vitamins and minerals that need to be supplied to the body in minute amounts (trace elements), are micro-nutrients. Water-soluble vitamins are vitamin C (ascorbic acid) and eight representative of the Vitamin B complex: biotin, folic acid, niacin, pantothenic acid, riboflavin (Vitamin B2), Thiamine (vitamin B1), vitamin B6 (pyridoxine) and vitamin B12 (cobalamin). Fat-soluble vitamins are vitamin A (retinol), vitamin D (cholecalciferol and ergocalciferol), vitamin E (alpha-tocopherol) and vitamin K (phylloquinone and menaquinone). Only vitamins A, E and B12 are stored to any significant extent in the body, the other vitamins must be supplied periodically to maintain tissue health. Essential trace elements include chromium, copper, iodine, iron, manganese, molybdenum, selenium and zinc. With the exception of chromium, all of these minerals form blocks of enzymes or hormones, which are needed for metabolism. With the exception of iron and zinc, a lack of micro minerals in developed countries occurs very rarely. so far there is no evidence of other minerals such as aluminum, arsenic, boron, cobalt, fluoride, nickel, silicon and vanadium that they could apply to humans as essential. Fluoride acts, although it is not essential, preventing against dental caries by combining and with calcium to calcium fluoride (CaF2), thereby stabilizing the mineralized matrix of teeth. All trace minerals are toxic in large quantities, some such as arsenic, nickel and chromium cause cancer. Other food components The human diet contains about 100,000 chemical substances (eg. As it contains coffee 1000). Of these substances can be 300 described as nutrients, of which again only a few are essential. Many food substances benefit the people, even though they are not among the nutrients. For example, improving additives such as preservatives, emulsifiers, antioxidants or stabilizers, the production and shelf life of food. Trace constituents present such as spices, flavors, smell, dyes, additives and other phytochemical natural ingredients make food more appealing and palatable. Dietary fiber Dietary fiber occur in various forms (eg., Cellulose, hemicellulose, pectin, gums). It increases GI motility, prevents constipation and helps in controlling diverticulosis. It is believed that fiber accelerate the elimination of carcinogenic substances produced by bacteria in the colon. Epidemiological studies suggest an association between colon cancer and low fiber intake as well as the beneficial effect of dietary fiber in patients with functional bowel disease, Crohn’s disease, obesity or hemorrhoids. Wasserlösliche Ballaststoffe, die in Obst, Gemüse, Hafer, Gerste und Hülsenfrüchten vorkommen, verringern den postprandialen Anstieg des Blutzucker- und Insulinspiegels und reduzieren den Cholesterinspiegel. Die typische Ernährungsweise der westlichen US-Bevölkerung gilt mit etwa 12 g/Tag als ballaststoffarm, da dort reichlich intensiv aufbereitetes Weizenmehl und wenig Obst und Gemüse verzehrt werden. Dementsprechend lauten Empfehlungen, die Ballaststoffzufuhr auf etwa 30 g/Tag zu erhöhen und mehr Gemüse, Obst und ballaststoffreiche Getreideprodukte und Körner zu verwenden. Eine sehr hohe Zufuhr von Ballaststoffen kann jedoch die Absorption bestimmter Mineralien verringern.