![]() Click Here to Sign Up for our Free Bodybuilding Newsletter BODYBUILDING FOOD AND NUTRITION
Nutrition begins with food. The science of nutrition concerns everything that the body does with food in order to live, function, grow, and heal.
CALORIESThe body's most basic need is for energy. To get energy it needs food as a fuel and oxygen to burn it. The amount of energy foods can produce is measured in units called calories. A food calorie, or kilocalorie, is the amount of heat required to raise the temperature of 1 kilogram (2.2 pounds) of water 1 degree Celsius (1.8 degrees Fahrenheit). Energy NeedsThe body changes the calories in food into energy, which is necessary for every act from blinking an eye to running a race. Energy is also used for the growing process, for rebuilding damaged cells, and for regulating body systems.
Stored EnergyIf a person takes in more food than required to meet the body's needs, the excess calories are converted to fat a stored form of energy. That causes weight gain. Eating too little causes weight loss because the fat is used for energy. One pound (0.5 kilogram) of stored fat contains about 3,500 calories.
NUTRIENTSTo function, the human body must have nutrients. The nutrients known to be essential for human beings are proteins, carbohydrates, fats and oils, minerals, vitamins, and water. ProteinsProteins are made of amino acids, small units necessary for growth and tissue repair. Protein is the body's most plentiful substance except for water and, possibly, fat. Animal foods such as meat, fish, poultry, milk, and eggs are rich in protein. Good plant sources of protein are beans, peas, nuts, bread, and cereals.
CarbohydratesStarches and sugars are carbohydrates, the main source of the body's energy. Carbohydrates account for about half of the calorie intake for most Americans and up to four fifths of the calories in diets of African and Asian peoples. Carbohydrate-rich foods are also the main sources of protein for most of the world. Rice, wheat, corn, and potatoes are common rich sources of carbohydrates.
Fats and OilsFats and oils (which are liquid fats) are a concentrated source of energy. Fats in the diet are necessary for good health. They make certain vitamins available for use in the body, they cushion vital organs, they make up part of all body cells, and they help to maintain body temperature. Fats also delay pangs of hunger because a food mixture containing fat remains longer in the stomach.
MineralsMinerals are neither animal nor vegetable; they are inorganic. Almost all foods contribute to a varied intake of essential minerals. Most minerals are easy to obtain in quantities required by the body. A major exception is iron for children under age 4 and adolescent girls and women in the childbearing years. These groups need more iron than a normal diet may provide. Iron helps to build red blood cells. It also helps the blood carry oxygen from the lungs to each body cell. Rich sources of iron are meat, especially liver; egg yolks; and dark green vegetables.
VitaminsThe discovery of vitamins began early in the 20th century. It is likely that some still are undiscovered. Eating a wide variety of foods ensures getting enough vitamins whether or not they are identified. All living things need vitamins for growth and health. The body either cannot manufacture them at all or cannot normally manufacture them in sufficient amounts, and so must absorb them from food. Each vitamin has specific roles to play. Many reactions in the body require several vitamins, and the lack or excess of any one can interfere with the function of another. Fat-soluble vitamins.Four vitamins A, D, E, and K are known as the fat-soluble vitamins. They are digested and absorbed with the help of fats that are in the diet.
Water-soluble vitamins.The vitamin B group of several vitamins helps to maintain healthy skin and a well-functioning nervous system. B vitamins also help to convert carbohydrates into energy. Vitamin C, or ascorbic acid, is needed for building the connective tissue that holds body cells together. Vitamin C is essential for healthy teeth, gums, and blood vessels. It also helps the body to absorb iron. These water-soluble vitamins are not stored in the body for long. Good sources should be eaten every day. WaterIn order to live, every cell in the body must be bathed in water. Water takes an active part in many chemical reactions and is needed to carry other nutrients, to regulate body temperature, and to help eliminate wastes. Water makes up about 60 percent of an adult's body weight. Requirements for water are met in many ways. Most fruits are more than 90 percent water. FOOD GUIDE PYRAMIDIn the early 1990s the long-standing, traditional basic four food groups, consisting of meat, dairy products, grains, and fruits and vegetables, were reworked into the more balanced and healthy food guide pyramid. This pyramid has as its base the grain group; on the second level are the fruit and vegetable groups; on the third level are the meat and dairy groups; and at the top is the fats, oils, and sweets group. Grain GroupAt the base of the food guide pyramid are breads, cereals, rice, pasta, and other foods made from grain. Human beings need more daily servings of these foods than any others because grain-based foods provide B vitamins, iron, carbohydrates, and some protein. Six or more daily servings are recommended. A serving, for example, is one slice of bread, one ounce (28 grams) of dry cereal, or one half cup of cooked pasta. Fruit Group and Vegetable GroupThe sources of most vitamins and minerals belong to these two groups. They also provide fiber, which contains no nutrients but aids in moving food through the digestive system. Three to five servings of vegetables and two to four servings of fruit should be eaten every day. One half cup of any fruit or vegetable counts as one serving. Dairy Group and Meat GroupOn this level are two groups of foods, such as milk, cheese, poultry, fish, and eggs, that come mostly from animals; notable exceptions are nuts and dried beans. These groups are quite high in protein, calcium, iron, phosphorus, the B vitamins, and zinc. Two to three servings from each group are recommended daily. Eight ounces (227 grams) of milk or 3 ounces (85 grams) of meat, for example, count as a serving. Fats, Oils, and Sweets GroupThe top of the pyramid includes foods that may add pleasure to eating but provide only calories and little nutritional benefit to one's diet. These foods include salad dressings, cream, butter, margarine, sugars, soft drinks, and candies. They should be eaten only sparingly. The American Heart Association recommends that no more than 30 percent of one's daily calories be derived from fat. DIETThe word diet comes from the Greek diaita, meaning "manner of living." Dietetics applies nutritional knowledge to the feeding of humans. Nutritional RequirementsFoods from the food guide pyramid may be part of any meal. A grilled cheese sandwich or a bowl of whole-grain cereal is just as nutritious in the morning as it is at noon. A good breakfast consists of any foods that supply about one fourth of the necessary nutrients for the day.
Fast Foods and Convenience FoodsFast foods and convenience foods are major parts of many people's diets. Convenience foods, such as TV dinners and cake mixes, are those prepared at home from foods already cooked or otherwise processed before reaching the retail store. Fast foods are prepared in quick-order restaurants (see Fast Food).
Special DietsSpecial diets for people with health problems should be prescribed by a physician. Many doctors refer patients to a dietitian, who draws up an individual diet plan.
MalnutritionMalnutrition is the imbalance between the body's demand for nutrients and the available supply of nutrients. Malnutrition can result from an unsatisfactory diet or from a disorder that interferes with the body's use of food.
Comptons Encyclopedia BIBLIOGRAPHY FOR FOOD AND NUTRITION Anderson, K.N., and Anderson, L.E. The International Dictionary of Food and Nutrition (Wiley, 1993). Barnard, Neal. Food for Life (Harmony, 1993). Camp, Charles. American Foodways: What, When, Why, and How We Eat in America (August House, 1989). Eastwood, Martin, and others. Human Nutrition: A Continuing Debate (Chapman and Hall, 1992). Epstein, Rachel. Eating Habits and Disorders (Chelsea House, 1990). Gebo, Sue. What's Left to Eat? (McGraw, 1992). Jacobson, M.F., and others. Safe Food (Berkeley Books, 1993). Lee, Sally. New Theories on Diet and Nutrition (Watts, 1990). Newhouse, Sonia. Complete Natural Food Facts (Thorsons, 1991). Salter, C.A. The Vegetarian Teen (Millbrook Press, 1991). Take some time and navigate around our site and do a little more research. And also don't forget to Sign Up for our Free Bodybuilding Newsletter
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