The pyramid of health

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In this pyramid level are complex carbohydrates. Carbohydrates arederived mainly from plants, including foods such as fruits, vegetables,pasta, rice, legumes (beans), and other grains fall in this category.Carbohydrates are very important to the body since they are the primarysource of energy. Some body tissues, such as red blood cells and most partsof the brain, can only use carbohydrate (glucose) for energy. You shouldeat 6-11 servings of carbohydrates each day, comprising 55-65% of yourdiet. Carbohydrates are broken down by the body into glucose, which is aform of sugar that is carried in the blood and transferred to cells forenergy. Some carbohydrates, such as pasta and bread, have been labeledfattening. This, however, can be said of all foods, no matter theirnutritional makeup. When a person consumes too many calories, the excesswill be stored as body fat, whether the foods were carbohydrates, proteins,or fats. Complex carbohydrates are long chains of glucose molecules. They areusually comprised of starches, which is the product of carbohydrate storagein plants. The major source of complex carbohydrates are whole grainproducts, such as whole wheat bread, brown rice, pasta, and beans.

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In fruits and vegetables are a lot of vitamins. The chemicalstructures of the vitamins are all known, and all of them have beensynthesized; the vitamins in foods are identical to the synthetic ones. Awell-balanced diet usually satisfies the minimum vitamin requirements ofhuman beings. The Recommended Dietary Allowance (RDA) of each vitamin isthe standard guideline put forward by the Food and Nutrition Board,National Academy of Sciences-National Research Council. It is based on thenutritional needs of an average, healthy person. Different amounts may berecommended for children, older people, lactating mothers, or peopledealing with an ongoing disease process.

   Vitamins were originally classified according to their solubility inwater or fats, and as more and more were discovered they were alsoclassified alphabetically. The fat-soluble vitamins are A, D, E, and K; theB complex and C vitamins are water soluble. A group of substances thatdecrease blood capillary fragility, called the vitamin P group, are nolonger considered to be vitamins.

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What does it do? Vitamin A is a fat-soluble vitamin with four majorfunctions in the body: (1) It helps cells reproduce normally—a processcalled differentiation (cells that have not properly differentiated aremore likely to undergo pre-cancerous changes). (2) It is required forvision; vitamin A maintains healthy cells in various structures of the eyeand is required for the transduction of light into nerve signals in theretina. (3) It is required for normal growth and development of the embryoand fetus, influencing genes that determine the sequential development oforgans in embryonic development. (4) It may be required for normalreproductive function, with influences on the function and development ofsperm, ovaries and placenta. [pic]

What does it do? Vitamin C is a water-soluble vitamin that has a number ofbiological functions. Acting as an antioxidant, one of vitamin C’simportant functions is to protect LDL cholesterol from oxidative damage.(Only when LDL is damaged does cholesterol appear to lead to heart disease,and vitamin C may be one of the most important antioxidant protectors ofLDL.) Vitamin C may also protect against heart disease by reducing thestiffness of arteries and the tendency of platelets to clump together.Vitamin C is needed to make collagen, the “glue” that strengthens manyparts of the body, such as muscles and blood vessels. Vitamin C also playsimportant roles in wound healing and as a natural antihistamine. This

vitamin also aids in the formation of liver bile and helps to fight virusesand to detoxify alcohol and other substances. [pic] Vitamin E (tocopherol) occurs in at least seven molecular forms,designated alpha-, beta-, gamma-, delta-, epsilon-, zeta-, and eta-tocopherol; all exist as light yellow, viscous oils. The best source isvegetable oils. Other sources include green leafy vegetables, wheat germ,and eggs. Tocopherol is necessary for the maintenance of cell membranes. Itis a potent antioxidant ; numerous studies have pointed to a protectiveeffect against arterial plaque buildup and cancer. It is helpful in therelief of intermittent claudication (calf pain) and in preventing problemspeculiar to premature infants. In large doses, it has an anticoagulanteffect.[pic] In this level are a lot of calcium. Calcium is the mineral in yourbody that makes up your bones and keeps them strong. Ninety-nine percent ofthe calcium in your body is stored in your bones and teeth. The remaining1% is in your blood and soft tissues and is essential for life and health.Without this tiny 1% of calcium, your muscles wouldn’t contract correctly,your blood wouldn’t clot and your nerves wouldn’t carry messages. It is mainly the calcium in your diet that spares, or protects, thecalcium in your bones. In addition to their structural role, your bones areyour emergency supply of calcium. Your body actually tears down and buildsbone all of the time in order to make its calcium available for your body’sfunctions. If you don’t get enough calcium from the food you eat, your bodyautomatically takes the calcium you need from your bones. If your bodycontinues to tear down more bone than it replaces over a period of years toget calcium, your bones become weak and break easily. This leads to the
crippling bone disease called “osteoporosis.”

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Protein molecule that consists of but a single polypeptide chain issaid to be monomeric; proteins made up of more than one polypeptide chain,as many of the large ones are, are called oligomeric. Based upon chemicalcomposition, proteins are divided into two major classes: simple proteins,which are composed of only amino acids, and conjugated proteins, which arecomposed of amino acids and additional organic and inorganic groupings,certain of which are called prosthetic groups . Conjugated proteins includeglycoproteins , which contain carbohydrates; lipoproteins, which containlipids; and nucleoproteins, which contain nucleic acids.

    Classified by biological function, proteins include the enzymes,which are responsible for catalyzing the thousands of chemical reactions ofthe living cell; keratin, elastin, and collagen, which are important typesof structural, or support, proteins; hemoglobin and other gas transportproteins; ovalbumin, casein, and other nutrient molecules; antibodies,which are molecules of the immune system (see immunity ); protein hormones,which regulate metabolism; and proteins that perform mechanical work, suchas actin and myosin, the contractile muscle proteins. [pic]

Fats and cholesterol have important functions in the body. Fats andoils are also called lipids. Fats are the most concentrated source of foodenergy. Per gram, fats have over twice as many calories as protein orcarbohydrates. Fats supply nine calories per gram, whereas carbohydrates(sugars and starches) and protein supply four calories per gram. Our bodiesstore excess dietary fats in fat cells to meet later energy needs. Excessdietary carbohydrates and protein also are converted into fat by our bodiesand stored for later use. In addition to supplying energy, fats have several importantfunctions. Fats give foods their characteristic flavors. Fats help providea feeling of satiety, or fullness. Dietary fats carry the fat-solublevitamins A, D, E, and K. Fats are also a source of the essential fatty

acids, linoleic acid and linolenic acid. Because the body cannot make theseessential fatty acids, they must be provided in the diet. Cholesterol is often confused with fat. Cholesterol is not atriglyceride, but a sterol. Sterols are fat-like compounds, made in thebody and found in foods. Cholesterol is part of the protective layer aroundnerve fibers and is a building block for cell walls. Cholesterol is alsoneeded for the production of certain hormones, vitamin D, and bile. Often fat and cholesterol are present together in food. However, thefat content of a food does not necessarily parallel cholesterol content.For example, vegetable oils that contain no cholesterol are still 100% fat.Further, chicken and fish may contain less fat than some cuts of beef, butthe cholesterol content is similar. Cholesterol is present in muscle tissueas well as fat.