Nutrition(1,3-f,4,6-bc,7)

Water

As the major body constituent present in every body cell, water accounts for between 50% and 60% of the adult's total weight. Infants have proportionately more water accounting for body weight. About two thirds of the body's water is contained within the cells (intracellular fluid [ICF]); the remainder is called extracellular fluid (ECF), which includes all other body fluids, such as plasma and interstitial fluid. Total body water and ECF decrease with age; ICF increases with an increase in body mass. Water is more vital to life than food because it provides the fluid medium necessary for all chemical reactions, it participates in many reactions, and it is not stored in the body. Water acts as a solvent that dissolves many solutes, thereby aiding digestion, absorption, circulation, and excretion. Through evaporation from the skin, water helps to regulate body temperature. As a lubricant, water is needed both for mucous secretions and for movement between joints. Sources of water in the diet include not only beverages but also solid foods, which contain between 10% and 98% water. Water is also produced through the metabolism of carbohydrates, protein, and fat. It leaves the body through urine, feces, expired air, and perspiration. Water intake (an average of 2,200 to 3,000 mL/day for adults) usually equals water output. Water balance may be seriously affected when intake (such as in older adults or people in comatose states) or output (such as in patients with altered renal function, profuse perspiration, diarrhea, vomiting, fistulas, drainage tubes, hemorrhage, severe burns) is altered.

Barriers to eating and risk to eating

Assess for barriers to eating. Dysphagia (difficulty swallowing or the inability to swallow) can be the result of poor dental health, cancer, or a neurologic disease, such as stroke, Parkinson's disease, or dementia, and may reduce the patient's nutritional intake. Dysphagia also is associated with an increased risk for aspiration, the misdirection of oropharyngeal secretions or gastric contents into the larynx and lower respiratory tract. Dental problems are associated with impaired chewing and avoidance of foods that may be difficult to chew, such as meat, fruit, and vegetables. Patients who experience weakness and fatigue may find eating to be a chore to avoid. Diminished sensor abilities, such as sight, taste, smell, and hearing, may also impact a patient's nutritional intake.

Carbohydrates (4)

Carbohydrates, commonly known as sugars and starches, are organic compounds composed of carbon, hydrogen, and oxygen. They serve as the structural framework of plants. The only animal source of carbohydrate in the diet is lactose, or "milk sugar." The significance of carbohydrates cannot be overstated. They are relatively easy to produce and store, making them the most abundant and least expensive source of calories in the diet worldwide. In countries where grains are the dietary staple, carbohydrates may contribute as much as 90% of total calories. Carbohydrate intake is often correlated to income. As income increases, carbohydrate intake decreases and protein intake, a more expensive form of energy, increases. CLASSIFICATION AND METABOLISM The number of molecules within the structure determines the classification of carbohydrates. They are classified as simple (monosaccharide and disaccharide) or complex (polysaccharide) sugars. Carbohydrates are more easily and quickly digested than protein and fat. Ninety percent of carbohydrate intake is digested. This percentage decreases as fiber intake increases. All carbohydrates are converted to glucose for transport through the blood or for use as energy. Glucose is an efficient fuel that certain tissues, particularly the central nervous system, rely on almost exclusively for energy. Glucose is transported from the GI tract, through the portal vein, to the liver. The liver stores glucose and regulates its entry into the blood. Hormones, especially insulin and glucagon, are responsible for keeping serum glucose levels fairly constant during both feasting and fasting. Through a series of steps, cells oxidize (burn) glucose to provide energy, carbon dioxide, and water. Depending on a person's state of energy balance, the period between when carbohydrate is consumed and when it is used for energy may vary from minutes to months or longer. Unlike protein and fat, glucose is burned efficiently and completely and does not leave a toxic product for the kidneys to excrete. When the supply of glucose exceeds what is needed for energy and for maintaining serum levels, it is stored. If muscle or liver glycogen stores are deficient, glucose is converted to glycogen and stored (glycogenesis). Conversely, glycogen is broken down in time of need to supply a ready source of glucose (glycogenolysis). When glycogen stores are adequate, the body converts excess glucose to fat and stores it as triglycerides in adipose tissue. FUNCTIONS AND RECOMMENDED DIETARY ALLOWANCE The primary function of carbohydrates is to supply energy. Except for indigestible fiber, all carbohydrates provide 4 calories per gram, regardless of the source. Recommended dietary allowance (RDA) of essential nutrients refers to recommendations for average daily amounts that healthy population groups should consume over time. Although an exact requirement for carbohydrates has not been established, at least 50 to 100 g are needed daily to prevent ketosis (an abnormal accumulation of ketone bodies that is frequently associated with acidosis). The Dietary Guidelines for Americans 2010 (U.S. Department of Agriculture [USDA] & Department of Health and Human Services [DHHS], 2010) recommends that carbohydrates provide 45% to 65% of total calories for adults, mostly in the form of complex carbohydrates. Sugars added to foods supply calories but few or no nutrients.

Dementia-BOX 35-7 Special Considerations and Interventions for Feeding Patients with Dementia or other Alterations in Cognition

Change the environment in which meals occur. Assess the area where meals are served. Create a home-like environment by preparing food close to the place where it will be served to stimulate senses. Observe as many former rituals as possible, such as handwashing and saying a blessing. Avoid clutter and distractions. Maintain a pleasant, well-lighted room. Play calming music. Keep food as close to its original form as possible. Serve meals in the same place at the same time. Closely supervise mealtime. Check food temperatures to prevent accidental mouth burns. Assist as needed. Be alert for cues from the patient. Turning away may signal that the patient has had enough to eat or that the patient needs to slow down. Leaning forward with an open mouth usually means the patient is ready for more food. Stroking the underside of the chin may help promote swallowing. Provide one food item at a time. Offer small, frequent eating opportunities. A whole tray of food may be overwhelming. Ensure that the patient's glasses and hearing aid are working properly. Demonstrate what you want the patient to do. State the goal clearly, and then mimic the action with exaggerated motions. Provide between-meal snacks that are easy to consume using the hands. Use adaptive feeding equipment as needed such as weighted utensils, large-handled cups, and larger or smaller silverware than standard. Promote family involvement to encourage eating.

NURSING CONSIDERATIONS FOR ENTERAL FEEDING

Facility and agency protocols may differ and should be followed, but nursing actions that contribute to successful tube feedings focus on patient safety, monitoring for complications, comfort, and education. Promoting Patient Safety. To promote patient safety when administering a tube feeding, be sure to include the following interventions as part of patient care: Check tube placement before administering any fluids, medications, or feeding, using multiple techniques: x-ray, pH testing, aspirate characteristics, external length marking, and carbon dioxide monitoring. Check gastric residual (feeding remaining in the stomach) before each feeding or every 4 to 6 hours during a continuous feeding (according to institution policy). High gastric residual volumes (200 to 250 mL or greater) can be associated with high risk for aspiration and aspiration-related pneumonia. Record residuals on flow sheet or in progress notes. Follow the clinician's order or facility policy for withholding feedings based on the residual. Some experts now recommend that the patient's pattern of residual is more important than the amount. Hold feedings if residual volumes exceed 200 mL on two successive assessments. It is important to note that it is important to flush the feeding tube with water after checking gastric residual, to help prevent tube occlusions. Assess the abdomen for abnormalities. Assess for bowel sounds at least once per shift to check for the presence of peristalsis and a functional intestinal tract. Experts, however, have recently concluded that it is common for acutely ill patients to have delayed gastric emptying; therefore, delaying enteral feedings based on hypoactive bowel sounds may place a patient at risk for malnutrition. Gastric distention, abdominal girth, nausea, vomiting, bloating, or pain are better indicators of how well a patient is tolerating a tube feeding. Make sure the patient is as upright as possible during feeding. If the patient is in bed during feedings, elevate the head of the bed at least 30 degrees during feeding and for 1 hour afterward to prevent reflux and aspiration. Pause the feeding if the patient has to be repositioned or temporarily laid flat. Resume the feeding only after the patient's head is returned to at least a 30-degree elevation. • Prevent contamination during enteral feedings by maintaining the integrity of the feeding system and using proper technique. Closed systems, consisting of a sterile, prefilled, ready-to-hang container, reduce the opportunity for bacterial contamination of the feeding formula. An open system exists when formula from a can or bottle is added to a feeding setup. Always check the expiration date of formula. Perform hand hygiene and put on nonsterile gloves before preparing, assembling, and handling any part of the feeding system. Disinfect the opening and rim of any cans to be opened before opening. Label all equipment with the patient's name, date, and time the feeding was hung, and cap or cover any disconnected tubing. Clean a reusable feeding system with soap and hot water every 24 hours; replace a disposable feeding apparatus for open systems every 24 hours. Closed systems can be used up to 48 hours; check manufacturer's guidelines and facility policy. Medications may be administered through a feeding tube, but never give them while a feeding is being infused. Administer liquid forms of medications whenever possible. Never add medications directly to the formula; some drugs become ineffective when mixed with feeding formulas; medications mixed in feeding formulas may cause clogging of the feeding tube. It is very important to flush the tube with water before, between, and after the administration of medications. Monitoring for Complications. Patients receiving tube feedings are at risk for several complications. In addition, prevent the tube from becoming clogged or obstructed. Common causes of clogged enteral tubes include aspirated stomach contents, residue from medications, slow feeding flow rate, infrequent or inadequate addition of water to the system, and using a tube with a small lumen. After checking placement, flush tube with 30 to 50 mL of water before and after each feeding or introduction of medications, at least every 4 hours during a continuous feeding, and after aspirating a tube for gastric contents. After flushing the tube, be sure to document the amount on the intake and output record. Use of a feeding pump helps to prevent clogging. If an occlusion occurs, use a 60-mL syringe containing 30 to 60 mL of warm water to attempt to unclog the tube. Providing Comfort Measures. Patients with nasogastric tubes often experience discomfort related to irritation to nasal and throat mucosa and drying of the oral mucous membranes. Implement several nursing interventions to ensure the patient's comfort and prevent alterations in the integrity of these tissues. Administer oral hygiene frequently (every 2 to 4 hours) to prevent drying of tissues and to relieve thirst. Offer the patient the opportunity to rinse the mouth with warm water and mouthwash solution frequently. Lubricate the lips generously. Keep the nares clean, especially around the tube, where secretions tend to accumulate. Using a lubricant after cleaning the nares is recommended. Help control local irritation from the tube in the throat. Analgesic throat lozenges or anesthetic sprays may be effective. Encourage the patient, if able, to verbalize concerns about tube feeding and presence of the tube. A visit from another person who has learned to cope with this alternate feeding method may prove helpful. Ensure that the tube is secured to the patient's nose and gown to prevent tension and tugging on the tube, causing trauma to the nares, and potential displacement. Providing Instruction. Often, patients will continue to receive enteral feedings at home. Provide the patient and family with individualized instructions in written form as a reference for the patient and caregivers. Be sure to include the following in the teaching plan: Information about the administration of feedings, operation of the pump, formula, instructions regarding rate and how to check for tube placement, as well as what to do if the tube becomes dislodged Care of the tube insertion site and possible complications that need to be reported Proper preparation, cleaning, and disposal of equipment Emergency telephone numbers, including the number for the home health care agency and the physician Arrangements for follow-up from the home health care nurse as soon as possible after discharge

Fats (9)

Fats in the diet, or lipids, are insoluble in water and, therefore, insoluble in blood. Like carbohydrates, they are composed of carbon, hydrogen, and oxygen. Ninety-five percent of the lipids in the diet are in the form of triglycerides, the predominant form of fat in food and the major storage form of fat in the body. Compound lipids (such as phospholipids, in which a lipid is combined with another substance) and derived lipids (such as cholesterol) constitute the remainder of the lipids ingested. CLASSIFICATION AND METABOLISM Food fats contain mixtures of saturated and unsaturated fatty acids. The difference in degree of saturation depends on the amount of hydrogen in fat molecules. Saturated fats contain more hydrogen than unsaturated fats. Most animal fats are considered saturated and have a solid consistency at room temperature. Saturated fats tend to raise serum cholesterol levels. Most vegetable fats are considered unsaturated, remain liquid at room temperature, and are referred to as oils. Unsaturated fats lower serum cholesterol levels. When manufacturers partially hydrogenate liquid oils, they become more solid and more stable. This substance is referred to as trans fats. Trans fat raises serum cholesterol. Therefore, it is to be counted in with the total number of saturated fats in a day. The U.S. Food and Drug Administration (FDA) requires that food nutrition labels list trans fat so that consumers may make healthy choices in their diet. Cholesterol is a fatlike substance found only in animal products. It is not an essential nutrient; the body makes sufficient amounts. Cholesterol is an important component of cell membranes and is especially abundant in brain and nerve cells. It also is used to synthesize bile acids and is a precursor of the steroid hormones and vitamin D. Although cholesterol serves many important functions in the body, high serum levels are clearly associated with an increased risk for atherosclerosis. To help lower serum cholesterol levels, researchers recommend limiting cholesterol intake, eating less total fat—especially saturated and trans fat—eating more unsaturated fat, and increasing fiber intake, which increases fecal excretion of cholesterol. Fat digestion occurs largely in the small intestine. Bile, secreted by the gallbladder, emulsifies fat to increase the surface area so that pancreatic lipase can break down fat more effectively. Through a complex series of events, most fats are absorbed into the lymphatic circulation with the help of a protein carrier and are transported to the liver. Of 100 grams eaten, only about 3 grams are excreted in the feces. FUNCTIONS AND RECOMMENDED DIETARY ALLOWANCE Fats are the most concentrated source of energy in the diet, providing 9 calories for every gram. Fat increases the palatability of the diet (e.g., to most people, filet mignon tastes better than flank steak) and has a high satiety value because it delays gastric emptying time. In the body, fat aids in the absorption of the fat-soluble vitamins and provides insulation, structure, and temperature control. The Dietary Guidelines for Americans 2010 recommends that fat intake be no more than between 20% and 35% of total caloric intake, with less than 10% of fat calories from saturated fats and less than 300 mg/day of cholesterol.

ADMINISTRATION OF ENTERAL FEEDING

Feeding Schedule. Based on the patient's physical, medical, and nutritional condition, the nutritionist usually makes recommendations concerning the feeding pattern or schedule. Continuous feedings allow gradual introduction of the formula into the GI tract, promoting maximal absorption. They require use of an enteral feeding pump, which limits the patient's mobility and increases cost. Continuous feeding into the stomach, however, is controversial because of the risk for reflux and aspiration. Feedings into the intestine are always continuous to avoid triggering dumping syndrome, as the natural reservoir of the stomach is bypassed. Dumping syndrome is caused by overdistention of the small intestine. The use of intermittent or bolus feedings would provide larger-than-normal amounts of food and liquid in the proximal small intestine, causing overdistention, leading to nausea, diarrhea, cramping, and lightheadedness. Intermittent feedings are the preferred method for gastric feeding. Intermittent feedings are delivered at regular intervals in equal portions, introducing the formula gradually over a set period of time via gravity or a feeding pump. Intermittent feedings resemble a more normal pattern of intake and allow the patient freedom of movement between feedings. Alternately, bolus intermittent feedings, for which a syringe is used to deliver the formula quickly into the stomach, may place the patient at risk for aspiration or cause distention. They are usually not recommended but may be used in long-term situations if tolerated by the patient. Another option is cyclic feeding. This involves administering continuous feeding for a portion of the 24-hour period. The usual routine is to feed the patient for 12 to 16 hours, most often overnight. Cyclic feeding allows the patient to attempt eating regular meals during the day, if this is possible, making ambulation and activity easier. Enteral Feeding Formulas. Many enteral feeding formulas are available. The nutritional composition of tube feedings depends on the feeding route, the patient's ability to digest and absorb nutrients, and the patient's nutrient and fluid requirements. Other considerations include the availability and cost of the formula, medical conditions that require diet modifications, food intolerance, and allergies. Standard formulas contain intact molecules of protein, carbohydrates, and fats, requiring the patient to have normal digestion and absorption. Hydrolyzed formulas contain proteins and other nutrients in simple forms that require little or no digestion. These formulas are used with patients with impaired digestion or absorption. In addition to being nutritionally balanced, formulas may be high in calories; contain fiber; contain additional protein; or be especially formulated for patients with respiratory, renal, or other health problems. Detailed information about their composition and caloric value (most routine formulas contain 1 to 1.2 cal/mL, although 2 cal/mL concentrations are available) can be obtained from the product label. Feedings are initiated at full strength. The rate of infusion begins at 25 to 50 mL per hour, depending on facility policy. The rate is then advanced by 10 to 25 mL per hour every 8 to 12 hours until the desired rate is achieved. Rate advancement is based on patient tolerance. Starting the feeding at a slower rate and progressing slowly improves tolerance. The previous practice of diluting feedings has not been shown to improve feeding tolerance and prolongs the period of inadequate nutrition support. Criteria to consider when evaluating patient feeding tolerance includes: Absence of nausea, vomiting Minimal or no gastric residual Absence of diarrhea and constipation Absence of abdominal pain and distention Presence of bowel sounds within normal limits Enteral Feeding Pumps. An enteral feeding pump regulates the amount of feeding solution that is delivered to the patient. A pump should be used when slow rates of enteral formula are required. The newer pumps are user friendly, have built-in safeguards that protect the patient from complications, and can be used in both institutions and the home. Safety features include automatic tube flush, cassettes that prevent free flow of formula, safety tips that prevent accidental attachment to an IV setup, and various audible and visible alarms. Most pumps can operate for up to 8 hours on battery. However, manufacturers recommend using the pump plugged into an electrical outlet for recharging whenever the patient is seated or resting for a period of time.

Food Labeling

Food labels provide a significant amount of nutritional information for the consumer. Regulations that control food labels have always been controversial. In 1975, the FDA, a federal agency charged with protecting the U.S. food and drug supply, enacted legislation for a standardized label format that was considered a positive step toward educating the consumer about nutrition. Confusion and misinformation resulted as food manufacturers oversimplified or exaggerated health claims for their products. In 1990, Congress passed the Nutritional Labeling and Education Act, which required all foods, including fruits and vegetables, to be clearly labeled. Four broad categories are addressed in this legislation. They include nutrition labeling, serving sizes, descriptors, and health claims. Starting January 1, 2006, labels were required to include information related to the amount of trans fat (trans fatty acids) on nutrition fact labels. Consumers should be easily able to identify the amount of saturated fat, trans fat, cholesterol, and dietary fiber included in a product, and the number of calories from fat, in addition to viewing a listing of other nutritional information. Figure 35-3 illustrates a sample label with explanation of terms. The food label is a tool to educate the public about nutrition and aid in choosing foods wisely.

Nasogastric (NG) tube

For short-term use (less than 4 weeks), a nasogastric or nasointestinal route is usually selected. A nasogastric (NG) tube is inserted through the nose and into the stomach. However, the patient is at risk for aspirating the tube feeding solution into the lungs, a disadvantage for using this route. Patients with a dysfunctional gag reflex, high risk of aspiration, gastric stasis, gastroesophageal reflux, nasal injuries, and those who are unable to have the head of the bed elevated during feedings are not candidates for nasogastric feeding. Traditional nasogastric tubes are firm and large in diameter. One example is a Levin tube. A Levin tube is a flexible rubber or plastic single-lumen tube with holes at the stomach end and a connector at the opposing end. The connector allows for attachment to a feeding apparatus and medication administration. Occasionally, a smaller, softer, more pliable polyurethane tube may be inserted via the nose into the stomach or small intestine. This type of tube is advantageous, providing greater patient comfort and less trauma to the nares. A Dobbhoff tube is an example of this type of tube. However, the smaller tube diameter makes checking tube placement and medication administration more difficult than with the larger-diameter tubes. Insertion of this tube requires skill and accuracy and is frequently done by the nurse.

TABLE 35-5 Clinical Observations for Nutritional Assessment

General appearance Alert, responsive Listless, apathetic, and cachetic General vitality Endurance, energetic, sleeps well, vigorous Easily fatigued, no energy, falls asleep easily, looks tired, apathetic, depressed mood Weight Normal for height, age, body build Overweight or underweight Hair Shiny, lustrous, firm, not easily plucked, healthy scalp Dull and dry, brittle, loss of color, easily plucked, thin and sparse Face Uniform skin color; healthy appearance, not swollen Dark skin over cheeks and under eyes, flaky skin, facial edema (moon face), pale skin color Eyes Bright, clear, moist, no sores at corners of eyelids, membranes moist and healthy pink color, no prominent blood vessels Pale eye membranes, dry eyes (xerophthalmia); Bitot's spots, increased vascularity, cornea soft (keratomalacia), small yellowish lumps around eyes (xanthelasma), dull or scarred cornea Lips Good pink color, smooth, moist, not chapped or swollen Swollen and puffy (cheilosis), angular lesion at corners of mouth or fissures or scars (stomatitis) Tongue Deep red, surface papillae present Smooth appearance, beefy red or magenta colored, swollen, hypertrophy or atrophy Teeth Straight, no crowding, no cavities, no pain, bright, no discoloration, well-shaped jaw Cavities, mottled appearance (Fluorosis), malpositioned, missing teeth Gums Firm, good pink color, no swelling or bleeding Spongy, bleed easily, marginal redness, recessed, swollen and inflamed Glands No enlargement of the thyroid, face not swollen Enlargement of the thyroid (goiter), enlargement of the parotid (swollen cheeks) Skin Smooth, good color, slightly moist, no signs of rashes, swelling, or color irregularities Rough, dry, flaky, swollen, pale, pigmented, lack of fat under the skin, fat deposits around the joints (xanthomas), bruises, petechiae Nails Firm, pink Spoon shaped (koilonychia), brittle, pale, ridged Skeleton Good posture, no malformations Poor posture, beading of the ribs, bowed legs or knock-knees, prominent scapulas, chest deformity at diaphragm Muscles Well developed, firm, good tone, some fat under the skin Flaccid, poor tone, wasted, underdeveloped, difficulty walking Extremities No tenderness Weak and tender, edema of lower extremities Abdomen Flat Swollen Nervous system Normal reflexes, psychological stability Decrease in or loss of ankle and knee reflexes, psychomotor changes, mental confusion, depression, sensory loss, motor weakness, loss of sense of position, loss of vibration, burning and tingling of the hands and feet (paresthesia) Cardiovascular system Normal heart rate and rhythm, no murmurs, normal blood pressure for age Cardiac enlargement, tachycardia, abnormal blood pressure GI system No palpable organs or masses (liver edge may be palpable in children) Enlarged liver or spleen

BOX 35-6 Biochemical Data with Nutritional Implications

Hemoglobin (normal = 12-18 g/dL) decreased → anemia Hematocrit (normal = 40%-50%) decreased → anemia increased → dehydration Serum albumin (normal = 3.5-5.5 g/dL) decreased → malnutrition (prolonged protein depletion), malabsorption Prealbumin (normal = 23-43 mg/dL) decreased → protein depletion, malnutrition Transferrin (normal = 240-480 mg/dL) decreased → anemia, protein deficiency Blood urea nitrogen (normal = 17-18 mg/dL) increased → starvation, high protein intake, severe dehydration decreased → malnutrition, overhydration Creatinine (normal = 0.4-1.5 mg/dL) increased → dehydration decreased → reduction in total muscle mass, severe malnutrition

Nursing Diagnosis-Imbalanced Nutrition: Less Than Body Requirements

Imbalanced Nutrition: Less Than Body Requirements related to nothing by mouth (NPO), inadequate tube feeding, prolonged use of a clear liquid diet, numerous food intolerance or allergies, excessive dieting, anorexia, chewing or swallowing difficulties, nausea, vomiting, chronic diarrhea, malabsorption, psychological eating disorders (anorexia nervosa, bulimia), alcoholism, metabolic and endocrine disorders, inappropriate use of supplements

Nursing Diagnosis-Imbalanced Nutrition: More Than Body Requirements

Imbalanced Nutrition: More Than Body Requirements related to overeating, inactivity, metabolic and endocrine disorders, inappropriate use of supplements

MyPlate Food Guide

In June 2011, the U.S. Department of Agriculture (USDA) replaced the MyPyramid with the MyPlate food guidance graphic. MyPlate is part of a communication initiative based on 2012 Dietary Guidelines for Americans to help consumers make better food choices. MyPlate is designed to remind Americans to eat healthfully. MyPlate illustrates the five food groups using a familiar mealtime visual, a place setting. The goals of the recommendations are to balance calories by encouraging consumers to enjoy food, but eat less, and avoid oversized portions. Consumers are also advised to increase the intake of vitamins, minerals, and dietary fiber by making half the plate fruits and vegetables, at least half of grains consumed whole grains, and switching to fat-free or low-fat (1%) milk. Consumers are encouraged to reduce sodium consumption by comparing sodium in foods like soup, bread, and frozen meals and choose foods with lower numbers. MyPlate also encourages the consumption of water instead of sugary drinks. The importance of activity and exercise are emphasized, including the recommendations for children and adolescents to be physically active for 60 minutes or more a day and adults to engage in activity that requires moderate effort, such as brisk walking for two and a half hours or more a week. Visitors to the website can personalize nutritional and physical activity plans, track foods consumed and physical activities, and get support to help make healthier choices.

BIOCHEMICAL DATA

Laboratory tests, which measure blood and urine levels of nutrients or biochemical functions that depend on an adequate supply of nutrients, can objectively detect nutritional problems in their early stages. Most routine biochemical tests measure protein status; measures of body vitamin, mineral, and trace element status are also available. Hemoglobin, the oxygen-carrying protein of the red blood cells, and hematocrit, the volume of red blood cells packed by centrifugation in a given volume of blood, are measures of plasma protein that also reflect a person's iron status. Protein status can also be determined by measuring serum albumin and transferrin levels and by a total lymphocyte count. Serum albumin levels are a good indicator of a patient's nutritional status a few weeks prior to when the blood is drawn and can help identify chronic nutrition problems. The albumin level does not change with increasing age, but malnutrition and various disease states cause its level to decrease. Serum albumin levels can also be affected by the patient's hydration status; overhydration can cause a low albumin level and dehydration may cause a very high level. Prealbumin levels indicate short-term nutritional status, can be used to detect daily changes in a patient's protein status, and are an excellent marker for malnutrition. Transferrin acts as an iron-transporting protein, but because it is related to iron levels may not always be an accurate indicator of nutritional status. The total lymphocyte count reflects immune status and is directly affected by impaired nutritional states. Blood glucose, blood cholesterol, and blood triglycerides are additional laboratory tests relative to nutritional status. Twenty-four-hour urine tests used to measure protein metabolism include urine creatinine excretion and urine urea nitrogen. Urea, a breakdown product of amino acids, can be measured in the urine and blood. It reflects protein intake and the body's ability to detoxify and excrete this metabolic byproduct. Creatinine levels are directly proportional to the body's muscle mass; a reduction in this value reflects severe malnutrition.

Minerals

Minerals are inorganic elements found in all body fluids and tissues in the form of salts (e.g., sodium chloride) or combined with organic compounds (e.g., iron in hemoglobin). Some minerals function to provide structure within the body, whereas others help to regulate body processes. Minerals, which are elements, are not broken down or rearranged in the body but, rather, are contained in the ash that remains after digestion. Excessive soaking and cooking in water can cause loss of minerals from food. However, minerals are commonly not destroyed by food processing. Macrominerals (bulk minerals), minerals needed by the body in amounts greater than 100 mg/day, include calcium, phosphorus (phosphates), sulfur (sulfate), sodium, chloride, potassium, and magnesium. Microminerals, or trace elements, are minerals needed by the body in amounts less than 100 mg/day. Microminerals that have recommended dietary intake established include iron, zinc, manganese, chromium, copper, molybdenum, selenium, fluoride, and iodine. Additional trace elements included arsenic, boron, nickel, silicon, cobalt, and vanadium. Dietary guidelines for these elements have not been established. Ultratrace elements are elements that are consumed in microgram quantities each day. They occur in very low quantities in human tissues and their essentiality is uncertain. These elements include aluminum, lithium, nickel, silicon, tin, and vanadium.

EXAMPLES OF NANDA-I NURSING DIAGNOSES NUTRITION

Nursing Diagnoses Imbalanced Nutrition: Less Than Body Requirements Related Factors Malabsorption Sample Defining Characteristics "I seem to eat all day long and yet I keep losing weight." Reports losing 15 lb within the past 3 weeks. Has 8 to 10 bowel movements daily of frothy, odorous stools that float. Fecal fat excretion test indicates steatorrhea. Patient appears fatigued and undernourished; muscle wasting is evident. Laboratory data reveal low serum albumin level (protein deficiency) and iron-deficiency anemia. Nursing Diagnoses Imbalanced Nutrition: More Than Body Requirements Related Factors Excessive intake in relation to physical activity Sample Defining Characteristics "I don't have time to eat at work." "I don't eat that much, but it is at night when I get home from work, usually around 7 PM, sometimes later." Patient reports a 10-lb weight gain within the past month and 50-lb weight gain in last year. Patient reports large food portion size in relation to suggested food guidelines. BMI 45; waist circumference 54 inches Patient reports job involves sitting at desk for most of day. Limited physical exercise. States: "Walking makes my back hurt, so I cannot walk for long periods of time." Nursing Diagnoses Impaired Swallowing Related Factors Neuromuscular impairment Sample Defining Characteristics "Food seems to get stuck." "Sometimes I can't finish eating because I cough too much." Swallowing evaluation study reports abnormality in oral and pharyngeal phases. Patient observed to have difficulty chewing; delayed swallow; gags and coughs during meal; gurgly voice quality noted after meal.

Protein (4)

Protein is a vital component of every living cell. Within the human body, more than 1,000 different proteins are made by combining various amounts and proportions of the 22 basic building blocks known as amino acids. Although amino acids, like carbohydrates, contain carbon, hydrogen, and oxygen, they differ in that amino acids also contain nitrogen. Nine amino acids are classified as essential because they cannot be synthesized in the body; they must be obtained from the diet. The remaining 13 amino acids are no less important, but because the body can make them as long as a supply of nitrogen is available, they are termed nonessential. Proteins are required for the formation of all body structures, including genes, enzymes, muscle, bone matrix, skin, and blood. Dietary proteins may be labeled complete (high quality) or incomplete (low quality), based on their amino acid composition. Complete proteins contain sufficient amounts and proportions of all the essential amino acids to support growth, whereas incomplete proteins are deficient in one or more essential amino acids. Generally, animal proteins (eggs, dairy products, meats) are complete, and plant proteins (grains, legumes, vegetables) are incomplete. The only exception is soy, a plant protein that is considered a complete protein. Because different sources of plant proteins lack different amino acids, a plant protein can be complemented by combining it with a different plant protein or by adding a small amount of an animal protein to supply a complete protein. Examples of complementary vegetable proteins include corn tortilla with refried beans and lentil rice soup. Complementary proteins that use a small amount of animal protein include cereal with milk, rice pudding, and a cheese sandwich. Complete protein = animal protein or plant protein + small amount of animal protein. Dietary protein is broken down into amino acid particles by pancreatic enzymes in the small intestine. These are absorbed through the intestinal mucosa to be transported to the liver. In the liver, amino acids are recombined into new proteins or are released into the bloodstream for use in protein synthesis by tissues and cells. Excess amino acids are converted to fatty acids, ketone bodies, or glucose and are stored or used as metabolic fuel. The body's protein tissues are in a constant state of flux. Tissues are continuously being broken down (catabolism) and replaced (anabolism). Nitrogen balance, a comparison between catabolism and anabolism, can be measured by comparing nitrogen intake (protein intake) and nitrogen excretion (nitrogen lost in urine, urea, feces, hair, nails, skin). When catabolism and anabolism are occurring at the same rate, as in healthy adults, the body is in a state of neutral nitrogen balance (i.e., nitrogen intake equals nitrogen excretion). A positive nitrogen balance occurs when nitrogen intake is greater than excretion, and indicates tissue growth—for example, during childhood, pregnancy, lactation, and recovery from illness. A negative nitrogen balance occurs when more nitrogen is excreted than is ingested, and indicates tissue is breaking down faster than it is being replaced. This undesirable state occurs in situations such as starvation and the catabolism that immediately follows surgery, illness, trauma, and stress. This can result in the wasting of muscle tissue as it is converted to glucose for energy. FUNCTIONS AND RECOMMENDED DIETARY ALLOWANCE The major function of protein is to maintain body tissues that break down from normal wear and tear and to support the growth of new tissue. Protein can be oxidized to provide 4 calories per gram. Using protein for energy is more expensive both financially and physiologically than using carbohydrates. The nitrogen remaining after protein is metabolized burdens the kidneys. In addition, energy must be used to excrete the nitrogen. Like carbohydrates, protein consumed in excess of need can be converted to and stored as fat. The recommended daily intake for protein for adults is 0.8 g/kg of desirable body weight, or about 46 g for a woman weighing 127 pounds and 56 g for a man weighing 154 pounds. Protein intake should contribute 10% to 35% of total caloric intake for adults (Dudek, 2014). Refer to Table 35-2 for more information about the sources, functions, and significance of protein.

Dysphagia-BOX 35-8 Special Considerations and Interventions for Feeding Patients with Dysphagia

Provide at least a 30-minute rest period prior to mealtime. A rested person will likely have less difficulty swallowing. Sit the patient upright, preferably in a chair. If bedrest is mandatory, elevate the head of the bed to a 90-degree angle. Provide mouth care immediately before meals to enhance the sense of taste. Avoid rushed or forced feeding. Adjust the rate of feeding and size of bites to the patient's tolerance. Collaborate to obtain a speech therapy consult for swallowing evaluation. Initiate a nutrition consult for appropriate diet modification such as chopping, mincing, or pureeing of foods and liquid consistency (thin, nectar-thick, honey-like, spoon-thick). Keep in mind that some patients may find thickened liquids unpalatable and thus drink insufficient fluids. Reduce or eliminate distractions at mealtime so that the patient can focus attention on swallowing. Alternate solids and liquids. Assess for signs of aspiration during eating: sudden appearance of severe coughing; choking; cyanosis; voice change, hoarseness, and/or gurgling after swallowing; frequent throat clearing after meals; or regurgitation through the nose or mouth. Inspect oral cavity for retained food. Avoid or minimize the use of sedatives and hypnotics since these agents may impair the cough reflex and swallowing.

Nursing Diagnosis-Risk for Imbalanced Nutrition:

Risk for Imbalanced Nutrition: More Than Body Requirements related to inappropriate eating, closely spaced pregnancies, metabolic and endocrine disorders, inappropriate use of supplements

Dietary Recommendations

The Dietary Guidelines for Americans are science-based strategies compiled by the Public Health Service of the Department of Health and Human Services and the U.S. Department of Agriculture. These guidelines provide advice to promote health and to reduce risk for major chronic diseases through diet and physical activity. Although these diet recommendations are not guaranteed to prevent diseases, many experts believe that most Americans can reduce their risk for chronic diet-related diseases, such as diabetes, certain types of cancer, and heart disease, by modifying the typical American or Western diet. The Public Health Service of the Department of Health and Human Services and the U.S. Department of Agriculture together update the Dietary Guidelines for Americans every 5 years.

Dietary Reference Intakes

The Dietary Reference Intakes (DRIs) provide recommended nutrient intakes for use in a variety of settings. The DRIs are actually a set of four reference values. The DRIs include: Recommended Dietary Allowance (RDA) is the average daily dietary intake of a nutrient that is sufficient to meet the requirement of nearly all (97%-98%) healthy people. Adequate Intake (AI) for a nutrient is established when an RDA cannot be determined. Therefore a nutrient either has an RDA or an AI. The AI is based on observed intakes of the nutrient by a group of healthy people. Tolerable Upper Intake Level (UL) is the highest daily intake of a nutrient that is likely to pose no risks of toxicity for almost all individuals. As intake above the UL increases, risk increases. Estimated Average Requirement (EAR) is the amount of a nutrient that is estimated to meet the requirement of half of all healthy people in the population. Each of these reference values distinguishes between gender and different life stages. RDAs, AIs and ULs are dietary guidelines for individuals, whereas EARs provide guidelines for groups and populations

Energy Nutrients

The body needs energy to function. Energy is derived or obtained from foods consumed. Energy in the diet is measured in the form of kilocalories, commonly abbreviated as calorie, or cal. Only carbohydrates, protein, and fat provide energy. Vitamins and minerals, needed for the metabolism of energy, do not provide calories. Total energy intake for a meal, a day, or longer, can be calculated by using food composition tables: The values given for total calories for each food item eaten can simply be added, or the grams of carbohydrate, protein, and fat for each food item eaten can be added and multiplied by the appropriate calorie level (4, 4, and 9 calories, respectively). Energy in the body is used to carry on any kind of activity, whether voluntary or involuntary. A person's total daily energy expenditure is the sum of all the calories used to perform physical activity, maintain basal metabolism, and digest, absorb, and metabolize food. If a person's daily energy intake is equal to total daily energy expenditure, the person's weight will remain stable. However, if the energy intake is less than the energy expended, the person's weight will decrease. If the energy intake exceeds energy expenditure, weight will increase.

PRINCIPLES OF NUTRITION

The science of nutrition is the study of how food nourishes the body. It encompasses the study of nutrients and how they are handled by the body as well as the impact of human behavior and environment on the process of nourishment. As such, this discipline involves physiology, psychology, and socioeconomics. Nutrients are specific biochemical substances used by the body for growth, development, activity, reproduction, lactation, health maintenance, and recovery from illness or injury. The metabolic processes involved in these functions are complex. Subsequently, most nutrients work better together than they do alone. Also, nutrient needs change throughout the life cycle in response to changes in body size, activity, growth, development, and state of health. Some nutrients are considered essential because either they are not synthesized in the body or are made in insufficient amounts. Essential nutrients must be provided in the diet or through supplements. Essential nutrients that supply energy and build tissue (such as carbohydrates, fats, protein) are referred to as macronutrients. Micronutrients, such as vitamins and minerals, are required in much smaller amounts to regulate and control body processes. Nonessential nutrients do not have to be supplied through dietary sources because they either are not required for body functioning or are synthesized in the body in adequate amounts. Some nutrients can be converted to others in the body. For instance, the body converts excess carbohydrates and protein into fat and stores them as triglycerides. Of the six classes of nutrients, three supply energy (carbohydrates, protein, lipids [fats]) and three are needed to regulate body processes (vitamins, minerals, water).

BOX 35-3 Summary of Dietary Guidelines for Americans 2010

To achieve adequate nutrients within energy needs: Maintain calorie balance over time to achieve and sustain a healthy weight. Focus on consuming nutrient-dense foods and beverages. To balance calories to manage weight: Prevent and/or reduce overweight and obesity through improved eating and physical activity behaviors. Control total calorie intake to manage body weight. For people who are overweight or obese, this will mean consuming fewer calories from foods and beverages. Increase physical activity and reduce time spent in sedentary behaviors. Maintain appropriate calorie balance during each stage of life—childhood, adolescence, adulthood, pregnancy and breastfeeding, and older age. Guidelines for physical activity include: Engage in regular physical activity and reduce sedentary activities to promote health, psychological well-being, and a healthy body weight. To achieve and maintain a healthy body weight, adults should do the equivalent of 150 minutes of moderate-intensity aerobic activity each week. If necessary, adults should increase their weekly minutes of aerobic physical activity gradually over time and decrease calorie intake to a point at which they can achieve calorie balance and a healthy weight. Some adults will need a higher level of physical activity than others to achieve and maintain a healthy body weight. Some may need more than the equivalent of 300 minutes per week of moderate-intensity activity. Foods and nutrients to increase: Increase vegetable and fruit intake. Eat a variety of vegetables, especially dark-green and red and orange vegetables and beans and peas. Consume at least half of all grains as whole grains. Increase whole-grain intake by replacing refined grains with whole grains. Increase intake of fat-free or low-fat milk and milk products, such as milk, yogurt, cheese, or fortified soy beverages. Choose a variety of protein foods, which include seafood, lean meat and poultry, eggs, beans and peas, soy products, and unsalted nuts and seeds. Increase the amount and variety of seafood consumed by choosing seafood in place of some meat and poultry. Replace protein foods that are higher in solid fats with choices that are lower in solid fats and calories and/or are sources of oils. Use oils to replace solid fats where possible. Choose foods that provide more potassium, dietary fiber, calcium, and vitamin D, which are nutrients of concern in American diets. These foods include vegetables, fruits, whole grains, and milk and milk products. Foods and food components to reduce: Reduce daily sodium intake to less than 2,300 milligrams (mg) and further reduce intake to 1,500 mg among persons who are 51 and older and those of any age who are African American or have hypertension, diabetes, or chronic kidney disease. The 1,500-mg recommendation applies to about half of the U.S. population, including children, and the majority of adults. Consume less than 10 percent of calories from saturated fatty acids by replacing them with monounsaturated and polyunsaturated fatty acids. Consume less than 300 mg per day of dietary cholesterol. Keep trans fatty acid consumption as low as possible by limiting foods that contain synthetic sources of trans fats, such as partially hydrogenated oils, and by limiting other solid fats. Reduce the intake of calories from solid fats and added sugars. Limit the consumption of foods that contain refined grains, especially refined grain foods that contain solid fats, added sugars, and sodium. If alcohol is consumed, it should be consumed in moderation—up to one drink per day for women and two drinks per day for men—and only by adults of legal drinking age. To build healthy eating patterns: Select an eating pattern that meets nutrient needs over time at an appropriate calorie level. Account for all foods and beverages consumed and assess how they fit within a total healthy eating pattern. Follow food safety recommendations when preparing and eating foods to reduce the risk of foodborne illnesses.

Vitamins

Vitamins are organic compounds needed by the body in small amounts. Most vitamins are active in the form of coenzymes, which, together with enzymes, facilitate thousands of chemical reactions in the body. Although vitamins do not provide energy (calories), they are needed for the metabolism of carbohydrates, protein, and fat. Vitamins are essential in the diet because most are not synthesized in the body or are made in insufficient quantities. The absence or insufficient use of vitamins in the body causes specific deficiency syndromes. Vitamins are present in foods in only small amounts. Fresh foods are higher in vitamins than processed foods because vitamins may be destroyed by light, heat, air, and during preparation. The exception is when vitamins not naturally occurring in a food are added, such as vitamin D-fortified milk. This process is called fortification. In the United States, severe vitamin deficiencies are uncommon. Mild or subclinical deficiencies of vitamin A, vitamin C, folate, and vitamin B6, however, may affect a significant proportion of the population, especially those who (1) are members of certain age groups or patient groups (infants, adolescents, pregnant and lactating women, older people); (2) smoke, abuse alcohol, or use medications on a long-term basis; (3) are chronically ill, either physically or psychologically; or (4) are poor or finicky eaters, such as chronic dieters and food faddists. Vitamins are classified as either water soluble or fat soluble. Water-soluble vitamins include vitamin C and the B-complex vitamins (ascorbic acid, thiamin, riboflavin, niacin, pyridoxine, biotin pantothenic acid, folate, cobalamin). They are absorbed through the intestinal wall directly into the bloodstream. Although some tissues are able to hold limited amounts of water-soluble vitamins, they usually are not stored in the body. Deficiency symptoms are apt to develop quickly when intake is inadequate; therefore, a daily intake is recommended. However, because water-soluble vitamins are not stored, amounts consumed in excess of need are excreted in the urine. Toxicities are not likely, although megadoses of certain water-soluble vitamins can be harmful. Vitamins A, D, E, and K, the fat-soluble vitamins, are absorbed with fat into the lymphatic circulation. Like fat, they must be attached to a protein to be transported through the blood. Secondary deficiencies of the fat-soluble vitamins can occur anytime fat digestion or absorption is altered, such as during malabsorption syndromes and pancreatic and biliary diseases. The body stores excesses of the fat-soluble vitamins mostly in the liver and adipose tissue. Because they are stored, a daily intake is not imperative and deficiency symptoms may take weeks, months, or years to develop. Excessive intake, particularly of vitamins A and D, is toxic. Many studies have attempted to evaluate the relationship of vitamin intake to diseases ranging from cardiovascular disease, osteoporosis, and neural tube defects to some types of cancers. Although scrutiny and research continue about vitamin supplements and their long-term effects, most nutritionists agree that vitamins will never be a substitute for good nutrition and healthy lifestyle practices. The Dietary Guidelines for Americans 2010 recommends that nutrient needs be met primarily through consuming foods. Supplements may be useful when they fill a specific identified nutrient gap that cannot or is not otherwise being met by the person's intake of food. Supplementation can ensure adequate intakes of specific nutrients because of physiologic limitations or changes. For example, folate (folic acid) supplementation during pregnancy has significantly decreased the risk of children born with neural tube defects.

Regulatory Nutrients

Vitamins, minerals, and water are regulatory nutrients because the body needs them for the metabolism of energy nutrients.