disorders of nutrition
Overview of Nutrition
Components of the Diet
Generally, nutrients are divided into two classes: Macronutrients are required daily in large quantities. They include Proteins , Micronutrients:Micronutrients are required daily in small quantities—in milligrams (one thousandth of a gram) to micrograms (one millionth of a gram). They include vitamins and certain minerals that enable the body to use macronutrients. These minerals are called trace minerals because the body needs only very small amounts. Water is required in amounts of 1 milliliter for each calorie of energy expended or about 2.7 liters (2.8 quarts) for women and 3.7 liters (3.9 quarts) for men a day. The requirement for water can be met by the water naturally contained in many foods and by drinking fruit or vegetable juices andcaffeine-free coffee or tea as well as water. Alcoholic beverages and caffeinated coffee, tea, and sodas may make people urinate more, so they are less useful. Foods consumed in the daily diet contain as many as 100,000 substances. But only 300 are classified as nutrients, and only 45 are classified as essential nutrients: Overview of Vitamins None Overview of Minerals None Some amino acids (components of protein) Some fatty acids (components of fats) Essential nutrients cannot be synthesized by the body and must be consumed in the diet. Nutrients that the body can make from other compounds are called nonessential. However, under certain conditions, such as illness or stress, the body may not make enough of these nonessential nutrients. Then, they need to be consumed in the diet, making themconditionally essential nutrients. Foods contain many other useful components, including Fiber (such as cellulose, pectins, and gums). Foods also contain Food Additives and Contaminants (such as preservatives, emulsifiers, antioxidants, and stabilizers), which improve the production, processing, storage, and packaging of foods. A diet is whatever a person eats, regardless of the goal. The best diet for older people has not been determined. However, people may benefit from changing some aspects of their diet as they age, based on the way the body changes as it ages. No changes are required for some nutrients such as carbohydrates and fats. Calories : Proteins : Fiber : Vitamins and Minerals and Water:As people age, they are more likely to become dehydrated because their ability to sense thirst decreases. Thus, older people need to make a conscious effort to drink enough fluids rather than wait until they feel thirsty. However, older people do not need to drink more water in general than younger people. Older people are more likely to have disorders or take drugs that can change the body’s nutritional needs or the body’s ability to meet those needs. Disorders and drugs can decrease appetite or interfere with the absorption of nutrients. When older people see their doctor, they should ask their doctor whether the disorders they have or the drugs they take affect nutrition in any way. 