Nutrition Guidelines

Eat a balanced diet. The key to good nutrition is a varied diet that includes every kind of nutrient. To simplify the planning of a varied diet, nutritionists have devised systems that group foods according to nutrient content. One such system divides foods into five groups: (1) vegetables, (2) fruit, (3) bread, cereals, rice and pasta, (4) milk, yog­hurt and cheese, (5) meat, poultry, fish, dried beans and peas, eggs and nuts.

Additional guidelines, called Recommended Dietary Allowances (RDAs), are provided in the United States by the Food and Nutritio Board of the National Academy of Sciences. In other countries, simi lar groups provide national nutrition guidelines. The RDAs give healt' experts estimates of the amounts of essential nutrients needed daily t maintain good nutrition in healthy people. This article includes a tabl of RDAs.

The RDA for a particular nutrient may vary depending on person' sex and age.

The RDA for iron, for example, is 12 milligrams for males age 1 to 18 and 15 milligrams for females age 11 to 50. The RDA for cal cium ranges from 400 milligrams for infants under the age of 6 month to 1.200 milligrams for males and females age 11 to 24 and for preg nant women.

People also vary in their needs for energy. A person who play sports daily, for example, needs more calories than someone who doe little physical work. Children need more calories than their size woul indicate because they are growing. Pregnant women also need extr calories to provide enough nutrients for a healthy baby.

Include fibre. Dietary fibre consists of cellulose and other complex carbohydrates that cannot be absorbed by the body. It passes out of the body as waste. Fibre moves food along through the stomach and intestines, thus helping to prevent constipation. Many experts believe that it also helps reduce the risk of such rectal and intestinal disorders as haemorrhoids, diverticulitis, cancers of the colon and rectum. Good sources of fibre include wholegrain breads and cereals, beans and peas, vegetables, and fruit.

Limit your intake of saturated fats and cholesterol. Health experts recommend a diet that is low in saturated fats and cholesterol, a waxy substance found in many animal foods. A high level of blood choles­terol increases the risk of heart disease. Animal products are the source of most saturated fats and all dietary cholesterol. To reduce the intake of saturated fats and cholesterol, health experts suggest choosing lean meats, fish, low-fat dairy products. They also advise using fats and oils sparingly.

Limit your intake of sodium and sugar. A diet that includes a great deal of sodium may increase the risk of high blood pressure, Sodium is found in many foods, including canned vegetables, pick­les, processed cheeses, table salt, and such snack foods as pretzels, potato chips, and nuts. One way to reduce sodium intake is to use herbs and other seasoning instead of salt in cooking and at the table Another way is to select fresh foods rather than canned or frozer foods.

Foods that contain a lot of sugar are often high in calories and fat but low in minerals, proteins, and vitamins. Nutritionists sometimes call them "empty calorie" foods, because they may make a person feel full but provide few nutrients. In addition, sugar that remains in and around the teeth contributes to tooth decay. Foods that have a large amount of sugar include candies, pastries, many breakfast cereals, and sweetened canned fruits. In place of sugary foods, nutritionists advise people to snack on such foods as fresh fruits and vegetables. They also recommended that people drink unsweetened fruit and vegetable juice instead of soft drinks.

Beware of alcohol. Alcoholic beverages supply calories, but they provide almost no nutrients. In addition, alcohol is a powerful drug, and habitual drinking can lead to many health problems. Health ex­perts recommend that if people choose to drink alcoholic beverages, they consume only small amounts. They suggest that certain people avoid alcohol altogether: children and adolescents, pregnant women, people who are about to drive, anyone who is taking medicine, and those who are unable to limit their drinking.

Дата добавления: 2015-08-13