Nutrition and Diet Therapy : The Relationship of Nutrition and Health

THE RELATIONSHIP OF NUTRITION AND HEALTH

The United States was historically referred to as the “melting pot” because it rep-resented people of many nationalities who immigrated to this country in hopes of finding a better life. The individuals in this country bring all their cultural diversi-ties with them, including their cuisine. Many choose to assimilate immediately by learning the language and trying the foods of their new country; others may favor the foods and customs of their country of origin. The diet that individuals follow will determine, to a large extent, their health, growth, and development. It has never been more imperative that active measures be taken to make our social, cultural, political, and economic environment in relation to diet a health-promoting one.

Taking care of one’s health is all about prevention. In the past, the focus was on treatment of diseases, with little, if any, attention to prevention. Preven-tion, however, can often be less costly than treatment and offer a better quality of life for an individual as well as the community. Nutrition and diet choice form a logical starting point for preventive health care measures and education to improve quality of life.

Achieving wellness that integrates body, mind, and spirit should be the main goal in life. This can be accomplished through lifestyle changes such as focusing on healthy food choices, not smoking, participating in regular physical activity, and maintaining a healthy weight. Expanding one’s mind through con-tinued education, in both nutrition and other areas, and finding a source of inner strength to deal with life changes will all contribute to one’s sense of wellness.

Living a long life without major health problems is possible. The younger one is when positive changes are made, the healthier one is throughout the life span.

NUTRIENTS AND THEIR FUNCTIONS

To maintain health and function properly, the body must be provided with nutrients. Nutrients are chemical substances that are necessary for life.They are divided into six classes:

 ·  Carbohydrates (CHO)

·  Fats (lipids)

·  Proteins

·  Vitamins

·  Minerals

·  Water

The body can make small amounts of some nutrients, but most must be obtained from food in order to meet the body’s needs. Those available only in food are called essential nutrients. There are about 40 of them, and they are found in all six nutrient classes.

The six nutrient classes are chemically divided into two categories: or-ganic and inorganic (Table 1-1). Organic nutrients contain hydrogen, oxygen, and carbon. (Carbon is an element found in all living things.) Before the body can use organic nutrients, it must break them down into their smallest compo-nents. Inorganic nutrients are already in their simplest forms when the body ingests them, except for water.

Each nutrient participates in at least one of the following functions:

 • Providing the body with energy

• Building and repairing body tissue

• Regulating body processes

Carbohydrates (CHO), proteins, and fats (lipids) furnish energy.Proteins are also used to build and repair body tissues with the help of vitamins and minerals. Vitamins, minerals, and water help regulate the various body processes such as circulation, respiration, digestion, and elimination.

Each nutrient is important, but none works alone. For example, carbohy-drates, proteins, and fats are necessary for energy, but to provide it, they need the help of vitamins, minerals, and water. Proteins are essential for building and repairing body tissue, but without vitamins, minerals, and water, they are ineffective. Foods that contain substantial amounts of nutrients are described as nutritious or nourishing.

Characteristics of Good Nutrition

Most people find pleasure in eating. Eating allows one to connect with family and friends in pleasant surroundings. This connection creates pleasant memo-ries. Unfortunately, in social situations it is easy for one to make food choices that may not be conducive to good health.

What determines when one needs to eat? Does one wait until the body signals hunger or eat when one sees food or when the clock says it is time? Hunger is the physiological need for food. Appetite is a psychological desire for food based on pleasant memories. When the body signals hunger, that is the indication that there is a decrease in blood glucose that supplies the body with energy. If one ignores the signal and hunger becomes intense, it is possible to make poor food choices. The choices one makes will determine one’s nutrition status. A person who habitually chooses to eat, or not to eat, as a way of coping with life’s emotional struggles may be suffering from an eating disorder.

Once foods have been eaten, the body must process it before it can be used. Nutrition is the result of the processes whereby the body takes in and uses food for growth, development, and the maintenance of health. These processes include digestion, absorption, and metabolism. One’s physical condition as determined by the diet is called nutritional status.

Nutrition helps determine the height and weight of an individual. Nutri-tion also can affect the body’s ability to resist disease, the length of one’s life, and the state of one’s physical and mental well-being Good nutrition enhances appearance and is commonly exemplified by shiny hair, clear skin, clear eyes, erect posture, alert expressions, and firm flesh on well-developed bone structures. Good nutrition aids emotional adjustments, provides stamina, and promotes a healthy appetite. It also helps establish regu-lar sleep and elimination habits.

MALNUTRITION

Malnutrition can be caused by overnutrition (excess energy or nutrient in-take) or undernutrition (deficient energy or nutrient intake). We usually think of malnutrition as a condition that results when the cells do not receive an 

adequate supply of the essential nutrients because of poor diet or poor utiliza-tion of food.

Sometimes it occurs because people do not or cannot eat enough of the foods that provide the essential nutrients to satisfy body needs. At other times people may eat well-balanced diets but suffer from dis-eases that prevent normal usage of the nutrients.

Overnutrition has become a larger problem in the United States than undernutrition. Overeating and the ingestion of megadoses of various vitamins and minerals (without prescription) are two major causes of overnutrition in the United States.

Nutrient Deficiency

A nutrient deficiency occurs when a person lacks one or more nutrients over a period of time. Nutrient deficiencies are classified as primary or secondary. Primary deficiencies are caused by inadequate dietary intake. Secondary defi-ciencies are caused by something other than diet, such as a disease condition that may cause malabsorption, accelerated excretion, or destruction of the nutrients. Nutrient deficiencies can result in malnutrition.

INDIVIDUALS AT RISK FROM POORNUTRITIONAL INTAKE

Teenagers may eat often but at unusual hours. They may miss regularly sched-uled meals, become hungry, and satisfy their hunger with foods that have low nutrient density such as potato chips, cakes, soda, and candy. Foods with low nutrient density provide an abundance of calories, but the nutrients areprimarily carbohydrates and fats and, except for sodium, very limited amounts of proteins, vitamins, and minerals. Teenagers are subject to peer pressure; that is, they are easily influenced by the opinions of their friends. If friends favor foods with low nutrient density, it is difficult for a teenager to differ with them. Crash diets, which unfortunately are common among teens, sometimes result in a form of malnutrition. This condition occurs because some nutrients are eliminated from the diet when the types of foods eaten are severely restricted.

Pregnancy increases a woman’s hunger and the need for certain nutrients, especially proteins, minerals, and vitamins. Pregnancy during adolescence requires extreme care in food selection. The young mother-to-be requires a diet that provides sufficient nutrients for the developing fetus as well as for her own still-growing body.

Many factors influence nutrition in the elderly. Depression, loneliness, lack of income, inability to shop, inability to prepare meals, and the state of overall health can all lead to malnutrition.

INDIVIDUALS AT RISK FROM POORNUTRITIONAL INTAKE

Teenagers may eat often but at unusual hours. They may miss regularly sched-uled meals, become hungry, and satisfy their hunger with foods that have low nutrient density such as potato chips, cakes, soda, and candy. Foods with low nutrient density provide an abundance of calories, but the nutrients areprimarily carbohydrates and fats and, except for sodium, very limited amounts of proteins, vitamins, and minerals. Teenagers are subject to peer pressure; that is, they are easily influenced by the opinions of their friends. If friends favor foods with low nutrient density, it is difficult for a teenager to differ with them. Crash diets, which unfortunately are common among teens, sometimes result in a form of malnutrition. This condition occurs because some nutrients are eliminated from the diet when the types of foods eaten are severely restricted.

Pregnancy increases a woman’s hunger and the need for certain nutrients, especially proteins, minerals, and vitamins. Pregnancy during adolescence requires extreme care in food selection. The young mother-to-be requires a diet that provides sufficient nutrients for the developing fetus as well as for her own still-growing body.

Many factors influence nutrition in the elderly. Depression, loneliness, lack of income, inability to shop, inability to prepare meals, and the state of overall health can all lead to malnutrition.

NUTRITION ASSESSMENT

That old saying, “You are what you eat,” is true, indeed; but one could change it a bit to read, “You are and will be what you eat.” Good nutrition is essential for the attainment and maintenance of good health. Determining whether a person is at risk requires completion of a nutrition assessment, which should, in fact, become part of a routine exam done by a registered dietitian or other health care professional specifically trained in thediagnosis of at-risk individuals. A proper nutrition assessment includes anthropometric measurements, clinical examination, biochemical tests, and dietary-social history.

Anthropometric measurements include height and weight and measure-ments of the head (for children), upper arm, and skinfold (Figure 1-3). The skinfold measurements are done with a caliper. They are used to determine the percentage of adipose and muscle tissue in the body. Measurements out of line with expectations may reveal failure to thrive in children, wasting (catabo-lism), edema, or obesity, all of which reflect nutrient deficiencies or excesses.

During the clinical examination, signs of nutrient deficiencies are noted. Some nutrient deficiency diseases, such as scurvy, rickets, iron deficiency, and kwashiorkor, are obvious; other forms of nutrient deficiency can be far more subtle.

Biochemical tests include various blood, urine, and stool tests. A defi-ciency or toxicity can be determined by laboratory analysis of the samples. The tests allow detection of malnutrition before signs appear. The following are some of the most commonly used tests for nutritional evaluation.

·  Serum albumin level measures the main protein in the blood and isused to determine protein status.

·  Serum transferrin level indicates iron-carrying protein in the blood.The level will be above normal if iron stores are low and below normal if the body lacks protein.

·  Blood urea nitrogen (BUN) may indicate renal failure, insufficient re-nal blood supply, or blockage of the urinary tract.

·  Creatinine excretion indicates the amount of creatinine excreted inthe urine over a 24-hour period and can be used in estimating body muscle mass. If the muscle mass has been depleted, as in malnutrition, the level will be low.

·  Serum creatinine indicates the amount of creatinine in the blood andis used for evaluating renal function.

Examples of other blood tests are hemoglobin (Hgb), hematocrit (Hct), red blood cells (RBCs), and white blood cells (WBCs). A low Hgb and Hct can indicate anemia. Not a routine test, but ordered on many clients with heart conditions, is the lipid profile, which includes total serum cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and serum triglycerides. Urinalysis also can detect protein and sugar in the urine, which can indicate kidney disease and diabetes.

The dietary-social history involves evaluation of food habits and is very im-portant in the nutritional assessment of any client. It can be difficult to obtain an accurate dietary assessment. The most common method is the 24-hour recall. In this method, the client is usually interviewed by the dietitian and is asked to give the types of, amounts of, and preparation used for all food eaten in the 24 hours prior to admission (PTA). Another method is the food diary. The client is asked to list all food eaten in a 3–4-day period. Neither method is totally accurate because clients forget or are not always totally truthful. They are sometimes inclined to say they have eaten certain foods because they know they should have done so. Computer analysis of the diet is the best way to determine if nutrient intake is ap-propriate. It will reveal any nutrient deficiencies or toxicities.

The dietary-social history is important to determine whether the client has the financial resources to obtain the needed food and the ability to properly store and cook food once home. After completing the dietary-social history, the dietitian can assess for risk of food–drug interactions that can lead to malnutri-tion (see Appendix E). Clients need to be instructed by a dietitian on possible interactions, if any.

When the preceding steps are evaluated together, and in the context of the client’s medical condition, the dietitian has the best opportunity of making an accurate nutrition assessment of the client. This assessment can then be used by the entire health care team. The doctor will find it helpful in evaluating the client’s condition and treatment. The dietitian can use the information to plan the client’s dietary treatment and counseling, and other health care pro-fessionals will be able to use it in assisting and counseling the client.

CONSIDERATIONS FOR THE HEALTHCARE PROFESSIONAL

The practice of good nutrition habits would help eliminate many health prob-lems caused by malnutrition (Figure 1-4). The health professional is obligated to have a sound knowledge of nutrition. One’s personal health, as well as that of one’s family, depends on it. Parents must have a good, basic knowledge of nutrition for the sake of their personal health and that of their children. Chil-dren learn by imitating their parents. Family members and friends who know that the health professional has studied nutrition will ask questions. Anyone, in fact, who plans and prepares meals should value, have knowledge of, and be able to apply the principles of sound nutrition practice.

Clients will have questions and complaints about their diets. Their anxi-eties can be relieved by clear and simple explanations provided by the health professional. Sometimes clients must undergo diet therapy, prescribed by their physicians, which becomes part of their medical treatment in the hospital. The health professional must be able to check the client’s tray quickly to see that it contains the correct foods for the diet prescribed. In many cases, diet therapy will have to be a lifelong practice for the client. In such cases, eating habits will have to be changed, and the client will need advice or instructions from a registered dietitian and support from other health professionals.

Nutrition is currently a popular subject. It is important to recognize that some books and articles concerning nutrition may not be scientifically correct. Also, food ads can be misleading. People with knowledge of sound nutrition practices will be less likely to be misled. They will recognize fad and distinguish it from fact.