Undernutrition

Undernutrition is what happens when the body does not get the nutrients it needs for good health or cannot use the nutrients it gets.

Many people think undernutrition is not a problem in the United States. But about 1 out of 6 older people are undernourished. Undernutrition is a problem for many older people who live alone or who live in a nursing home.

Undernutrition and weight loss do not always go together. People can be undernourished without losing weight. They can be overweight and undernourished. And people can lose weight, particularly if they are trying to do so, without becoming undernourished.

Most people who do not consume enough food also do not consume enough vitamins and minerals, sometimes resulting in a vitamin or mineral deficiency. Many do not drink enough fluids, sometimes resulting in dehydration.

Causes

Undernutrition may result from eating too little food (that is, too few calories). But it may result even when enough food is eaten if the foods chosen do not contain enough of the needed nutrients, particularly protein, vitamins, and minerals. People may choose foods that are low in nutrients but high in calories (called empty-calorie foods). People may eat only a few foods rather than the variety needed to provide enough nutrients. Undernutrition may also result when the body cannot absorb nutrients from foods.

Older people are more susceptible to undernutrition for several reasons.

• Changes due to aging: In some older people, changes due to aging itself cause the appetite to decrease. So less food may be eaten.
• Disorders and drugs: Many older people have disorders or take drugs that change the body's nutritional needs or make the body less able to meet those needs. For example, a disorder can cause the body to burn more calories, so more food is needed. Or a disorder (such as depression) or drug can decrease the appetite. Some disorders (such as a stroke or dental problems) can make eating difficult.
• Living situation: Many older people live and eat alone and thus are less motivated to prepare and eat meals. Older people may also eat less because funds are limited or because shopping for or preparing food is difficult. Caregivers providing meals for older people may be unaware of which foods are nutritious. In nursing homes, older people may not be served foods they like. Or they may not receive the help or time they need to eat. Older people who are hospitalized may have some of the same problems.

Sometimes undernutrition has one cause. But more often, several conditions work together to cause undernutrition.

For additional detail on this topic, see Causes of Undernutrition.

Symptoms

The appearance of people who are undernourished may not change. If only a specific nutrient (such as protein) is lacking, their weight may be normal or higher. However, many undernourished people are obviously underweight and have little or no body fat. They may notice that their clothes fit more loosely or that they have lost muscle.

As undernutrition becomes more severe, the temples may look hollow and bones may protrude. The skin may become thin, dry, inelastic, pale, and cold. The hair may become dry and sparse. It may fall out easily. Undernourished people often lose muscle. They may feel tired, sleepy, weak, and dizzy. As a result, they are more likely to fall. Infections may develop more often. Sores or wounds may be slow to heal.

In older people, undernutrition is often part of a general decline. People may gradually become less able to think clearly and to take care of themselves. They may become depressed and withdraw from friends and family. This decline is called failure to thrive.

Many older people do not notice any changes or symptoms as they become undernourished. Family members and caregivers may notice the changes first. However, caregivers may think that weight loss in older people is normal. Also, older people may not think losing weight is a problem. They may not connect symptoms they are having with what they are eating or not eating.

Diagnosis

Undernutrition can sometimes be identified based on appearance. Maintaining a weight that is too low or losing weight without trying, even for people who are overweight, may indicate undernutrition.

To determine whether people are undernourished, health care practitioners measure weight and height. From these measurements, they can calculate body mass index (BMI). Practitioners may ask whether weight has recently been lost and, if so, how much and over what period of time. They also ask people what and how much they eat and drink each day. However, for most people, this information is difficult to recall. Practitioners may ask whether people consider themselves well-nourished and generally healthy. Whether people recognize the problem affects their willingness to participate in a treatment plan.

Practitioners may measure around the arm or waist to estimate the percentage of fat and muscle (body composition). Blood tests may be done to measure the levels of cholesterol and albumin (the main protein in the blood). Cholesterol levels become low when not enough calories are consumed. The albumin level may decrease when not enough protein is consumed.

Health care practitioners ask about problems that may be contributing to undernutrition: disorders, drugs, alcohol consumption, mood, living situation, and the need for help (with paying for, shopping for, preparing, or eating meals).

Prevention and Treatment

Preventing undernutrition is better than treating it. Restoring people to their previous level of health and functioning takes a lot longer than undernutrition takes to develop. Many of the same measures help prevent and treat undernutrition.

Generally, to prevent undernutrition, older people should eat a varied diet. It should include lots of fruits and vegetables, protein-rich foods (such as fish and poultry), and high-fiber breads and cereals. Drinking plenty of fluids is also important. Water, fruit or vegetable juices, and caffeine-free coffee and tea are good choices. For most healthy, active older people who eat a varied diet, eating large amounts of a particular food or using dietary supplements is not necessary.

For people with a small appetite, making meals more appetizing may help. For example, foods with different flavors, textures, colors, and temperatures can be included in a meal. Tastes and smells can be enhanced by using spices. However, people with high blood pressure or heart failure should use salt moderately. Too much salt can make these disorders worse. Eating with other people can make meals more appealing. Physical activity such as walking before meals helps stimulate appetite.

If preparing food is difficult, prepared foods (such as frozen dinners) can be purchased. Periodically, family members or friends can help cook foods in quantity. Then the foods can be packaged in appropriate portions to freeze and be eaten later. A microwave or toaster oven may make food preparation easier. Some gadgets (such as electric can openers) are also helpful.

If shopping is difficult, family members or friends may be able to help. Churches, synagogues, mosques, and community organizations sometimes provide shopping services. Some senior centers offer meals, and some organizations, such as Meals on Wheels, bring meals to the home. These meals are inexpensive or free.

Help with buying appropriate foods and preparing healthy meals may be all that is needed to prevent or treat undernutrition. The companionship and stimulation that come with this kind of help may also boost a person's interest in eating.

If funds are limited, organizations and programs (such as food stamps) can help. They are often listed in the telephone book. People can ask a health care practitioner for help with getting this information.

Dental problems should be treated. Having a tooth extracted or getting dentures that fit properly can make eating easier. If eating remains difficult, foods that are hard to chew can be chopped finely, mashed, or blended. Peanut butter, eggs, cheese, yogurt, or beans can be substituted for meat as sources of protein.

Treating disorders that contribute to undernutrition can help. If depression or an anxiety disorder is interfering with eating, antidepressants or antianxiety drugs may lessen these feelings. However, some of these drugs can decrease appetite.

People who are undernourished should limit their consumption of alcohol to one drink a day.

A dietitian can teach a family member or caregiver which foods help an undernourished person and which foods do not.

Nutritional supplements that are rich in carbohydrates, protein, and fat are often useful for people who are not eating enough. Supplements are available as powders or thick liquids with or without a prescription. There are many nutritional supplements. All are equally effective.

When other measures are ineffective, undernourished people may be given drugs to stimulate appetite and promote weight gain. Corticosteroids, growth hormone, other hormones, and dronabinol may be used but are often ineffective. Also, whether these drugs can be safely taken for a long time is unclear.

Some people cannot take nutritional supplements by mouth. For example, some people who have had a stroke cannot swallow. In such cases, supplements can be given through a tube inserted through the nose and throat into the stomach. If feeding through a tube is needed for a long time, the tube may be inserted directly into the stomach or small intestine through a small incision in the abdomen.

Tube feeding can cause problems. Among older people, the most common problem is the movement of food backward into the esophagus and throat (reflux). Food in the throat can be breathed into the lungs (aspirated). Aspirating food can result in pneumonia. Food is less likely to be aspirated when the head of the bed is raised. Tube feeding can also cause diarrhea and abdominal discomfort.

The tube, whether inserted through the nose and down the throat or through an incision in the abdomen, can irritate tissues, causing inflammation and infection.

For people whose digestive tract cannot absorb enough nutrients, a solution containing nutrients can be given through a tube inserted in a vein (intravenously). Food given intravenously is called parenteral nutrition. When all of a person's food is given this way, it is called total parenteral nutrition.

In older people, intravenous feeding is usually used only for a short time. When used for a long time, it can cause problems. Infections are more likely because bacteria can enter the body through the incision for the tube. Also, when there is no food in the intestine, bacteria can pass through the wall of the intestine into the bloodstream. Intravenous feeding may lead to vitamin and mineral deficiencies. Electrolyte levels can become dangerously high or low if people are fed too fast, too much, or too little or if they have been undernourished for a long time.

See the sidebar Eating in a Nursing Home.