Undernutrition in older adults is serious because it increases the risk of fractures, problems after surgery, pressure sores, and infections. If any of these problems occur, they are more likely to be severe in people who are undernourished.

Older adults are at risk of undernutrition for many reasons.

Age-related changes in the body: In the aging body, production of and sensitivity to hormones (such as growth hormone, insulin, and androgens) change. As a result, older adults lose muscle tissue (a condition called sarcopenia). Undernutrition and decreased physical activity worsen this loss. Also, the age-related loss of muscle tissue accounts for many of the complications of undernutrition in older adults, such as a higher risk of infections.

As people age, their need for nutrients increases but they burn fewer calories. So older adults need to consume foods that contain a lot of nutrients but are low in calories. Such a diet may be hard to follow.

Older adults tend to feel full sooner and have less of an appetite. Thus, they may eat less. They may also eat less because as people age, the ability to taste and smell decreases, reducing the enjoyment of food. The ability to absorb some nutrients is reduced.

Some older adults produce less saliva, resulting in dental problems and difficulty swallowing.

Disorders: Many disorders that contribute to undernutrition are common among older adults.

• Depression can cause loss of appetite.

• A stroke or tremors may make chewing, swallowing, or preparing food difficult.

• Arthritis or other physical impairments, which reduce the ability to move, may make shopping for and preparing food more difficult.

• Malabsorption disorders interfere with the absorption of nutrients.

• Cancer can reduce the appetite and increase the body’s need for calories.

• Dementia can make people forget to eat or become unable to prepare food and thus lose weight. People with advanced dementia cannot feed themselves and may resist attempts by others to feed them.

• Dental problems (such as ill-fitting dentures or gum disease) may make chewing and thus digesting food more difficult.

• Anorexia nervosa that has been present for a long time may be made worse by an event late in life, such as death of a partner or fear of aging.

Medications: Many of the medications used to treat disorders common among older adults (such as depression, cancer, heart failure, and high blood pressure) can contribute to undernutrition. Medications can increase the body’s need for nutrients, change how the body uses nutrients, or decrease the appetite. Some medications cause diarrhea or have side effects that interfere with eating, such as nausea and constipation.

Living situation: People who live alone may be less motivated to prepare and eat meals. They may have limited funds, causing them to buy cheap, less nutritious food or less total food. They may be physically unable or afraid to go out to buy food or may not have transportation to a grocery store.

People who live in institutions have even more obstacles to adequate nutrition.

• They may be confused and unable to say when they are hungry or what they would like to eat.

• They may be unable to choose foods they like.

• They may be unable to feed themselves.

• If they eat slowly, especially if they need to be fed by a staff member, the staff member may not have or allow enough time to feed them adequately.

• Inadequate exposure to sunlight combined with inadequate consumption of food and age-related changes can lead to .

People who are hospitalized sometimes have the same problems.

Prevention and treatment: Older adults can be encouraged to eat more, and food can be made more appealing. For example, strongly flavored or favorite foods, rather than low-salt or low-fat foods, can be served.

Older adults may be following a special diet (such as a low-salt diet) because they have a disorder (such as kidney failure or heart failure). However, such diets are sometimes unappealing and lack taste. If so, people may not eat enough food. In such cases, they or their family members should talk to the dietitian or doctor about how to make foods that taste good to them and that fit with their dietary requirements.

People who need help with grocery shopping or feeding themselves should be given more help. For example, they may need for meals to be delivered to their home.

Depression and other disorders, if present, should be treated. Treating these disorders may remove some of the obstacles to eating.

For older adults living in institutions, making the dining room more attractive and giving them more time to eat may enable them to eat more.