Nutrient Requirements

Nutrient Requirements
Approximately 40 nutrients through the human body needs. Nutrients are essential if they are not synthesized by the body and if a defect to detect anomalies that, if the deficit has been corrected disappear causes. Nutrients are essential amino acids, water-soluble vitamins, fat soluble vitamins, minerals and essential fatty acids. The organization also requires an adequate energy substrate, a small amount of metabolizable carbohydrate, indigestible carbohydrates (dietary fiber), nitrogen and water. The nutrient requirements were expressed most frequently by the Recommended Dietary Allowance (RDA). Edited and at regular intervals by the Food and Nutrition Board of the National Academy of Sciences of the GDR were checked originally designed to meet the nutritional requirements of almost all well known in good health. RDA have for carbohydrates and protein, water-soluble vitamins thiamin, riboflavin, niacin, vitamin B6, folic acid, vitamin B12 and vitamin C, fat-soluble vitamins A, C and E proved, minerals and copper, phosphorus, magnesium, iron, zinc, iodine, selenium and molybdenum.
Energy
The body needs energy to support normal function and physical activity, growth and repair of damaged tissue. Power is supplied by the oxidation of dietary proteins, fats, carbohydrates and alcohol. The oxidation of 1 g of the respective provides 4 kcal of energy from protein and carbohydrate, 9 kcal kcal from fat and alcohol 7th In healthy adults, the energy expenditure mainly by three factors: basal energy expenditure (BEE), the thermal effect of food (TEF) and physical activity is determined. The bee is the amount of energy needed to maintain basic physiological functions upright. It is measured while the subject at rest in a warm room that is not eaten for 12 hours. In healthy people, BEE (in kcal/24 h) may be replaced by the Harris-Benedict equation to predict correctly BEE measured in 90% ± 10% of healthy subjects (see below Nutritional support are appreciated). In clinical practice, patients rarely meet the stringent criteria for the measurement of BEE. Instead, energy expenditure in subjects at rest without food is measured for two hours. This measure, the basal metabolic rate (REE), is about 10% higher than BEE. EFT, the energy expended during and after eating, on average, about 10% of the bee. Physical activity has a major impact on energy expenditure.
Carbohydrates
A small amount of carbohydrate 100 g / d, is necessary to prevent ketosis. In practice, however, a significant proportion of food energy are supplied by carbohydrates. The average American consumes 45% of calories as carbohydrates. Dietary carbohydrates include simple sugars, complex carbohydrates (starch) and indigestible carbohydrates (dietary fiber). The bulk of food carbohydrates from starch must be whole-grain and sugar in fruit and vegetable derived found found. Sucrose and other forms of added sugar such as corn syrup, high fructose are a concentrated source of calories, with no other sources of nutrients and contribute to the consumption of excess calories. Consumption of sucrose is also an important factor in the development of caries. Strengths, as a raw material supply of calories from carbohydrates, vitamins, minerals and fiber. Fiber is the part of the plant, which can not be digested by the human intestine. Fiber increases stool bulk and facilitates excretion. Diets high in fiber with a reduced incidence of cardiovascular and gastrointestinal diseases associated. The insoluble fibers, like those found in wheat bran, have the greatest effect on large bowel function. Soluble fiber, as found in beans, oats, fruit and lead to lower blood sugar levels in diabetics and lower cholesterol.
Fat
Dietary fat is a concentrated source of energy in the diet. As the energy of food carbohydrate, energy from fat supports the protein synthesis. Dietary fat also provides essential fatty acid linoleic acid. Other than the need for a sufficient amount of linoleic acid, there are no special requirements for dietary fat, as long as the diet provides enough nutrients oxidizable energy. Although the average American consumes 35-40% of calories from fat, the current recommendations on dietary fat to 20-35% of the calories are limited. to diets with less than 5-10% of calories as fat appear to be safe and well tolerated. The fats are composed mainly of fatty acids and cholesterol. The fatty acids contain either no double bonds (saturated), a double bond (single) or more unsaturated double bonds (multiple times). Saturated fats are associated with increased serum cholesterol, while polyunsaturated and monounsaturated fatty acids lower serum cholesterol. Trans-fatty acids, a special form of content of unsaturated fatty acids in partially hydrogenated vegetable oils, also raise serum cholesterol. Saturated fats are solid at room temperature and are usually derived from animal products, unsaturated fats are liquid at room temperature and are derived mainly from plant foods. The polyunsaturated fatty acid linoleic acid is an essential nutrient that the body needs for the synthesis of arachidonic acid, the main precursor of prostaglandins. A deficiency of linoleic acid leads to dermatitis, hair loss and healing wounds. to cover for people with an average energy, about 5 g linoleic acid per day is necessary for 1-2% of total calories to prevent essential fatty acid deficiency.
Cholesterol
is an important component of cell membranes. It is synthesized by the body and is not an essential nutrient. Diets that contain large amounts of cholesterol partially inhibit endogenous cholesterol synthesis, but also a net increase in serum cholesterol concentrations due to the suppression of the synthesis of low density lipoprotein receptors. Average American diets contain about 450 mg / day of cholesterol, but 300 mg or less per day is recommended. Vitamins
Vitamins are a heterogeneous group of organic molecules necessary for the organization of a variety of basic metabolic functions. They are grouped into water-soluble vitamins: Thiamin, Riboflavin, Niacin, Vitamin B6 (pyridoxine), Vitamin B12 (cobalamin), folic acid, pantothenic acid, biotin and vitamin C (ascorbic) and fat-soluble vitamins A, D, E and K.