17.3 Specialized Diets

Standards for a Healthy Diet

A healthy diet is one that meets the daily recommended intake for macronutrients and micronutrients. Based on the Healthy Eating Index, the USDA recommends the following pattern for dietary intake:

• carbohydrates: 50 to 60 percent of calories per day with less than 10 percent added sugars
• fat: 20 to 30 percent of calories per day with less than 10 percent saturated fat
• protein: 10 to 20 percent of calories per day
• fiber: 25 grams per day
• fluids: 2.5 liters per day

The USDA recommends daily allowances for sodium, calcium, and vitamins D and B12 as well. A healthy diet must take into consideration individual caloric needs. Caloric needs are based on biological sex, age, and activity level. Some diets require strict adherence to the USDA recommendations, including calorie counting; however, the average patient will benefit from teaching related to general principles. Here are some general guidelines for healthy eating:

• Eat a variety of foods, including plenty of vegetables, fruits, and whole grains.
• Choose healthy proteins such as lean meats, fish, poultry, low-fat dairy products, and legumes.
• Drink plenty of water.
• Limit salt, alcohol, saturated and trans fats, and added sugar.
• Eat whole foods as much as possible and avoid highly processed foods.

A healthy diet prioritizes the consumption of sufficient amounts of vegetables and fruits on a daily basis. Vegetables and fruits should be eaten whole whenever possible. There are different categories of vegetables: dark green, red and orange, beans, nuts and seeds (legumes), and starches such as potatoes and cassava. Fruits may be fresh or frozen, canned, or dried. It is best to limit fruit juices, which may be high in calories.

Whole grains are an important part of a healthy diet; they include products made from wheat, rice, or oats that have not been refined. Refined grains, such as white rice and white flour, are grain kernels that have been processed to remove the bran and germ covering of the grain. This refining process removes important nutrients, such as fiber, iron, and vitamins. Whole grains use the entire grain kernel and are more nutritious than refined grains.

Foods that are high in protein include animal products such as seafood, beef, poultry, and eggs, as well as plant-based foods such as beans, peas, seeds, and nuts. Protein choices should be lean and varied. Dairy is a good source of protein, vitamins, and minerals, but low-fat versions of milk, yogurt, and cheese are typically healthier choices. Fats should be limited to 20 to 30 percent of calories, with strict limits on saturated fats. Oils are liquid fats that provide important nutrients. Oils are classified as unsaturated, polyunsaturated, or saturated. A healthy diet will include unsaturated or polyunsaturated fats and limit saturated fats.

Dietary teaching for everyone should focus on developing consistent eating patterns that include healthy amounts of carbohydrates, proteins, fats, and plenty of fresh water. A healthy diet should limit added sugars, saturated fats, sodium, and alcohol. Due to the variety of foods available, dietary choices can easily be adapted to meet cultural, religious, or budgetary preferences.

MyPlate

MyPlate (Figure 17.5) is a dietary tool developed by the USDA to help individuals maintain healthy eating patterns throughout life. MyPlate uses a 9-inch plate as a visual tool for meeting the USDA’s general guidelines. Using the MyPlate method, vegetables and fruits make up half the plate, grains make up roughly a quarter of the plate, and proteins make up the final quarter. A serving of low-fat dairy is included as well. A personalized MyPlate plan is based on age, sex, height, weight, and activity level. The MyPlate website and MyPlate app are available to identify calorie needs and provide simple planning recommendations based on individual needs.

Figure 17.5 Through MyPlate, the USDA provides guidance on healthy eating to ensure individuals receive the RDA for each nutrient. (credit: “Start Simple with MyPlate” by U.S. Department of Agriculture, Public Domain)

Link to Learning

Go to the MyPlate website and explore the USDA’s recommendations for a nutritious diet.

Food Labeling

Scientists and government agencies have developed food labels to improve decision-making regarding nutrition intake. The USDA Dietary Guidelines provide recommended daily intakes based on DRIs for macronutrients, micronutrients, and fiber. Food labels report the recommended daily allowances for specific nutrients as a percent daily value per serving. A serving is not a regulated amount but rather a typical volume of food consumed. Food labels always identify the number of servings per container, the number of calories per serving, and the percent daily value per serving for specific nutrients.

Sometimes, manufacturers will choose to include daily values per container. Labels must include, but are not limited to, the following nutrients: carbohydrates, calcium, iron, potassium, vitamin D, fat, and protein. Fats are broken down into total fat, percent saturated fat, and cholesterol. Carbohydrates are broken down into total carbohydrates, fiber, total sugar, and added sugar. In general, a serving with a percent daily value of 5 percent or less for a nutrient is considered to have a low nutrient value. A serving with a percent daily value of 20 percent or more is considered to have a high nutrient value. A law passed in 2016 required food manufacturers to update their labels. Figure 17.6 details the changes.

Figure 17.6 Updated food labels now list added sugars and potassium, clarify the meaning of percent daily value, and have been reformatted to improve readability. (credit: modification of work “What’s on the Nutrition Facts Label?” by U.S. Food and Drug Administration, Public Domain)

Food Safety

Food safety is an important part of healthy living. The goal of food safety is to prevent foodborne illnesses such as bacterial infections. The following organisms are the cause of most foodborne infections: Campylobacter, Salmonella, and Escherichia coli. Symptoms common to these infections are nausea, vomiting, diarrhea, abdominal pain, and fever. Public health departments have foodborne surveillance programs that include a national reporting system to track outbreaks. Salmonella, Shigella, and Listeria are organisms commonly included in the national reporting system. Shigella is a highly contagious intestinal infection. Listeria is caused by improper processing or pasteurization and is most harmful to individuals who are pregnant, older, or immunocompromised. Surveillance helps track infections and identify outbreaks for public health intervention.

Prevention is key to food safety and reducing the effects of foodborne illness. Whether food is being prepared in the home, a restaurant, or an institution, the same four principles of food safety apply:

1. Keep hands, utensils, and surfaces clean.
2. Separate raw meat, seafood, and eggs from other foods.
3. Cook foods to the appropriate internal temperature.
4. Chill cooked foods within two hours.

Healthy food practices are essential to good health. Nurses should reinforce these prevention strategies by encouraging good hygiene and appropriate food handling practices and providing resources for patient education.

Consistent Carbohydrate Diet

Carbohydrates are often misunderstood. Many people limit carbohydrates as a means of calorie control, yet both simple and complex carbohydrates are healthy and important nutrients. There are conditions under which carbohydrates must be controlled, however. An example of a diet focused on carbohydrate control is the consistent carbohydrate diet, which is recommended as a treatment for diabetes. Diabetes is a metabolic disorder affecting the utilization of glucose by the body cells. Poor glucose utilization can lead to acute acid-base disturbances and chronic effects including immune dysfunction, cardiovascular disease, and neurovascular changes. The negative effects of diabetes can best be prevented by effective blood sugar control.

The consistent carbohydrate diet maintains the recommended amount of carbohydrates per day (40 to 60 percent of the diet) but is designed to meet metabolic goals through the consumption of consistent carbohydrates at each meal. This consistency spreads out the carbohydrates over all daily meals with the goal of maintaining steady glycemic control throughout the day, avoiding hypoglycemic and hyperglycemic blood glucose swings. This mimics the healthy body’s natural tendency toward glucose control and insulin release. The consistent carbohydrate diet limits the use of added sugars and encourages healthy carbohydrate choices at each meal. The emphasis is on controlling carbohydrates rather than calories. This diet supports healthy dietary patterns for all individuals, encouraging regular consumption of whole grains, whole fruits and vegetables, and low-fat dairy products, and avoiding added sugars and refined and processed foods.

Fat-Restricted Diet

Twenty to 30 percent of a healthy diet should include fat, an essential, energy-dense macronutrient. Unfortunately, not all fat is considered “good” fat. In general, individuals eating a healthy diet should limit saturated fat to 10 percent of calories consumed. Most saturated fat comes from animal proteins. Because fat is associated with increased risk of obesity, heart disease, hypertension, and stroke, individual treatment plans may include fat-restricted diets to limit risk or decrease disease progression.

Fat-restricted diets adhere to the same USDA recommendations for a healthy diet, which is to consume between 20 and 30 percent of calories as fat but limit the types of fat consumed by avoiding saturated and trans fats. Saturated fat is typically solid at room temperature and is high in cholesterol. High-fat meats, butter, whole milk products, and coconut oil are common saturated fats. Trans fats are artificially produced by a process called hydrogenation. Partially hydrogenated fats are found in processed foods such as cookies, crackers, and margarine spreads. For patients with heart disease or at risk for developing heart disease, the American Heart Association recommends eliminating trans fats and limiting saturated fats to 5 to 6 percent of calories consumed, which is significantly lower than the dietary standard of 10 percent. Substituting more monounsaturated and polyunsaturated fats, such as canola, olive, and corn oils, is a healthy way to obtain needed fat in the diet while reducing the risk associated with “bad” fats.

High-Fiber Diet

Dietary fiber is a type of carbohydrate that adds bulk to aid in digestion. Fiber is found in plant foods and is categorized as soluble or insoluble. A high-fiber diet is recommended for most individuals, as it improves digestive health, aids in weight control, and reduces the risk of colon cancer and other intestinal disorders. Foods high in fiber include whole fruits and vegetables, whole grains, and legumes. High-fiber foods are known to decrease risk of gastrointestinal disorders, cardiovascular disease, and many metabolic disorders and should be included in all healthy diet routines.

Low-Fiber Diet

There are a few conditions that contraindicate a high-fiber diet. Limiting the fibrous content of foods eases digestion. Medical conditions that require periods of gastrointestinal rest benefit from a short-term reduction in fiber intake. Gastrointestinal rest allows for limited stimulation and processing in the intestinal tract, and a low-fiber diet is often included in the treatment plan. Eggs, creamy nut butters, low-fiber whole grain cereals, vegetable and fruit juices, applesauce, and canned fruits and vegetables can be included in a low-fiber diet. This diet should avoid all raw or undercooked vegetables, whole grains, nuts, seeds, and fibrous meats. A low-fiber diet is often used following intestinal surgeries or radiation treatments to the abdomen. Fiber should be slowly added back into the diet as digestive health returns.

Sodium Restriction Diet

The general population should limit sodium intake to less than 2,300 mg/day. Sodium is an essential element needed for many basic physiological processes. Sodium aids in food processing as a flavor enhancer, a curing agent and preservative, and a thickening agent. It also helps regulate the moisture content of food. Because of its versatility, many processed foods are high in sodium content. Unfortunately, high sodium levels increase the risk of cardiovascular disease and hypertension and negatively impact fluid balance within the body. Therefore, sodium-restricted diets are commonly prescribed for individuals with heart disease or at risk for heart disease and chronic fluid retention.

The first step in maintaining a low-sodium diet is to eliminate processed foods from the diet. Eating whole, natural foods keeps the diet naturally low in sodium. Next, all food labels should be carefully monitored for sodium content. Products with less than 200 mg per serving are healthy choices for this diet. Eating a diet high in fresh fruits and vegetables and fresh lean meats, reading food labels, and substituting herbs and spices for added salt are important ways to maintain a low-sodium diet and manage health risks.

Kidney Diet

The kidneys regulate fluid and electrolyte balance in the body. The kidneys are made up of nephrons, which filter the blood to produce urine. A kidney diet is prescribed when kidney function becomes chronically impaired and restricting certain nutrients is necessary to preserve kidney function. Foods high in protein, sodium, and potassium are limited in a kidney diet. Protein metabolism leads to waste products that must be filtered by the kidneys; therefore, a kidney diet will limit protein (animal or plant based) to small portions (2–3 oz). Because water follows sodium in the body, high sodium in the blood can lead to excess fluid volume and increased blood pressure. Because high blood pressure adversely impacts the function of delicate nephrons, sodium restrictions are placed to help preserve kidney function. With advanced kidney disease, phosphorous and potassium are also restricted. While most people on a kidney diet should have 2,000 mL intake of fluid daily, in advanced disease fluid may be restricted even further based on individual need. Routine lab work is required to monitor kidney function, fluid status, and electrolytes.

High-Calorie, High-Protein Diet

A high-calorie, high-protein diet may be prescribed when there is a need for extra nutrition to aid healing. Individuals with extensive burns or poor healing wounds may be placed on a diet rich in quality proteins, providing needed energy and nutrients to speed healing and tissue repair. This diet minimizes carbohydrate intake and increases protein intake. Proteins with high amounts of saturated fats should be avoided. Egg whites, fish, fowl, dairy, and legumes are excellent protein choices. Avocados, cheese, nuts, and dried fruit make excellent calorie-dense snack choices. Weight trends must be closely monitored; also, because high protein levels can negatively impact kidney function, kidney labs must be routinely followed.

Liquid Diet

Liquid diets are used to meet short-term clinical goals. Liquids are classified by the consistency of the fluid. Clear liquids melt to a transparent fluid that contains no pulp. A full liquid is a fluid that contains sufficient residue but still maintains a fluid form. Sometimes the consistency of liquids is restricted based on viscosity. Liquid diets are implemented for a variety of reasons and are often an essential part of the treatment plan.

Soft Diets

Soft diets are diets in which the consistency and texture of the food are manipulated to improve swallowing or digestion. These diets typically contain lower fiber (less than 2 grams per serving) and a soft texture. They exclude fibrous meats, raw vegetables and fruits, beans, shellfish, and whole grains. The texture is dependent on the specific impairment. Soft diets are often used for patients with some degree of dysphagia or for postsurgical care.

Nasogastric and Orogastric Tubes

NG tubes are sometimes placed when food cannot be safely ingested. They are utilized for the short term only, typically less than four weeks. The NG tube is a single- or double-lumen tube that is passed through the nares, pharynx, and esophagus and into the stomach; it can be used for suctioning stomach contents and administering medications in addition to providing enteral nutrition. Orogastric (OG) tubes work in the same manner except they are inserted through the mouth into the esophagus and then into the stomach. OG tubes are typically used with mechanically intubated and sedated patients and should never be used in conscious patients because they can induce a gag reflex and cause vomiting.

Percutaneous Enteral Gastrostomy Tube

A PEG tube is placed directly through the abdominal wall via endoscopy. The PEG tube is placed in the stomach for direct administration of formula feeds and medications. In some situations, the tube can be advanced through the gastric pouch into the proximal part of the small intestine (jejunostomy). PEG tubes and jejunostomies are utilized when alternative nutrition is needed long term. PEG tubes may also be used when there is an obstruction to the esophagus, or the esophagus has been removed. Percutaneous endoscopic jejunostomy (PEJ) tubes are inserted through the abdominal wall directly into the jejunum, bypassing the esophagus and stomach. PEJ tubes are used when all or part of the stomach has been removed or if the provider determines PEJ placement would best suit the patient’s needs.

Nursing Considerations for Administration

Nursing considerations for enteral nutrition involve management of care concerning placement and maintenance of the tube, administration of formula feeds and medications, and prevention and monitoring of complications. Care is dependent on the type of tube being used and the underlying medical conditions of the patient.

An NG tube can be placed by a nurse but requires a clinician’s order. Once placed, the NG tube is anchored to the nose or cheek, and the length of the external tubing is documented. Placement must be verified via x-ray imaging prior to use. A PEG tube or jejunostomy is placed by a physician via endoscopic procedure. Placement is also verified by x-ray imaging prior to use. The placement of NG and PEG tubes must be verified prior to every subsequent use, per facility protocol. The tubing is monitored for migration every shift and with every use. If placement of the tube is in question, gastric contents can be aspirated and their pH tested for appropriate acidity. Follow-up x-rays can be ordered for reevaluation of placement if needed. Incorrect placement can lead to aspiration or perforation.

The registered dietitian determines the type of formula needed following patient assessment. The nurse administers the enteral feeding as prescribed. Enteral nutrition can be administered via bolus or pump with a set volume and rate of administration. Free water flushes are commonly administered prior to and following administration or in tandem with an enteral feeding pump. Tubing should be assessed for migration and obstructions with every formula feed. The nurse should monitor for leakage and skin breakdown. The tubing should be cleansed routinely according to facility protocol, typically using water or saline and soft gauze. Any redness or purulent drainage should be documented and reported.

Enteral feedings are associated with complications. It is the nurse’s responsibility to mitigate these types of risk:

• To reduce the risk of aspiration,
  • maintain slow, steady administration rates;
  • keep the patient’s head of bed elevated 30° to 45° as tolerated;
  • monitor for migration of visible NG/OG tubing; and
  • assess for residual gastric contents and follow facility policy for rate reduction protocols.
• To reduce the risk of clogged tubing,
  • flush the tube with water every shift and prn (as needed),
  • flush tubes before and after administration of feedings or medication,
  • assess for any residual gastric contents and follow facility policy for rate reduction protocol, and
  • irrigate tubing per facility protocol.
• To reduce the risk of gastric distress,
  • administer feedings at room temperature;
  • maintain prescribed rate of administration;
  • assess placement every shift and prior to feeding or medication administration; and
  • assess for signs of gastric distress including nausea, diarrhea, abdominal pain, and distension.

Types of Parenteral Nutrition

PN requires central venous access. A central venous catheter is inserted in the jugular or subclavian vein and terminates in the vena cava. Central lines can be tunneled for long-term use (months to years) or nontunneled for intermittent use. Peripherally inserted central catheter (PICC) lines are long catheters inserted through a vein in the arm. Commonly, the basilic vein is used, terminating in the superior vena cava. PICC lines are used for intermediate use, typically weeks to months. Standards of care must be followed to reduce complication rates and improve patient outcomes. Policies regarding the care and use of central lines should follow facility protocols.

Nursing Considerations for Administration

Nursing considerations related to PN include catheter care, administration of parenteral nutrition (PN), preventing and responding to complications, and ongoing assessment of nutritional status. Nurses should follow these guidelines for central line care and administration of PN:

• PICC dressings should be changed every seventy-two hours using sterile technique.
• PN should be administered through a dedicated lumen.
• Parenteral tubing should be changed every twenty-four hours.
• The PN label should be verified against the documented order.

Complications associated with PN include central line infections, sepsis, poor blood sugar control, hepatic dysfunction, and fluid and electrolyte imbalance. Nursing interventions should be geared toward prevention:

• Maintain strict sterile technique for central line care.
• Monitor vital signs routinely.
• Monitor blood sugar and administer insulin per protocol.
• Assess for fluid imbalance.
• Monitor labs for trends involving electrolytes, kidney, and liver function.