CHAPTER 3 DIET THERAPY
This chapter is concerned with the nutritional requirements for the healthy and for the sick, wounded, and convalescing patient. Research has proved that good health in part depends upon the availability of essential elements that the body needs throughout life. The well-nourished in- dividual is usually mentally alert, is at a maximum of physical capability, and has a high resistance to disease. The daily basic minimum nutritional requirements must also be met and often times supplemented during periods of illness to meet changing needs of the body and its ability to use foods. Therefore, the diet is an important factor of the therapeutic plan for each patient.
FOOD CLASSIFICATION
Foods are substances from the animal, plant, and mineral kingdoms that, when taken into the body, yield heat and energy, build and renew tissues, and regulate the body processes. Nutrients are classified as proteins, fats, carbohydrates, minerals, vitamins, and water.
PROTEINS
Proteins are important nutritive elements re- quired by man. They are found in both the animal and plant kingdoms. All proteins are composed of amino acids, some of which are absolutely essential to maintain life and are necessary for repair, growth, and body development. Proteins, which promote tissue growth and renewal, have long been recognized as the main structural unit of all living cells. Each gram (g) of protein yields 4 calories in the process of metabolism, (If sufficient carbohydrate is not supplied, the body will use protein for energy requirements. This protein may be obtained from muscle tissue to produce a “wasting effect” in some diseases or long term starvation. ) Although proteins also yield energy, they are an expensive source. A constant protein source is required in the daily diet. The normal daily protein intake for adults should be .08 gram per kilogram (g/kg) (2.2 lbs) of body weight, or 12 percent of the total caloric intake, as indicated in the 1980 revision of the Recommended Daily Allowances, prepared by the Food and Nutrition Board, National Academy of Sciences, National Research Council. Pregnant women require 1.2 g of protein per kg of body weight.
Proteins play an important role in recovering from injuries of all kinds, such as fractures, burns, and infections. They are also important in healing wounds and recovering from surgical procedures. Protein intake should be increased in accordance with the severity of the above conditions. Calories must be sufficiently high in order to spare protein for tissue repair. Carbo- hydrates and fats can be added liberally. Ideally, the patient should receive protein by mouth; however, it is sometimes necessary to meet the minimum requirements through the parenteral route. Glucose parenteral solution, given during the acute emergency period, will prevent some loss of protein. Protein deficiency may stunt growth, promote a secondary anemia, or induce nutri- tional edema. Dietary sources of protein are milk, yogurt, eggs, meats, fish, cheese, poultry, peanut butter, legumes, and nuts. (Protein from plant sources is best used combined with animal protein, such as milk plus peanut butter, or if legumes are combined with grains, such as Navy beans plus rice.)
FATS
The chief functions of fats are to supply energy and transport fat-soluble vitamins. Each g of fat yields 9 calories. Fats provide the most concentrated source of calories (thus energy) of all the food nutrients. They are found in both the animal and vegetable kingdoms. Fatty acids and glycerol are the end products of the diges- tion of fats. In the normal diet, fats should