When an elderly relative does not want to eat, it can be emotionally distressing. No cause is identified in approximately 26 percent of cases, according to Evaluating and Treating Unintentional Weight Loss in the Elderly, published in 2002 in "American Family Physician." However, doctors find medical causes in the other cases. Consult a doctor when a loss of appetite results in a weight loss of 5 percent to 10 percent within one year.
The elderly have an increased risk of all forms of cancer. Cancer in the elderly is related to a condition called cachexia anorexia syndrome. Cachexia is a gradual weight loss, weakening and loss of muscle strength, while anorexia is a loss of appetite. Over time, both conditions result in malnutrition. According to the article "Geriatric Cachexia" published in 1999 in "American Journal of Clinical Nutrition," the body releases chemicals called cytokines in the presence of cancer. Cytokines interfere with appetite by causing nausea, vomiting and decreased bowel motility. Cancers of the lung and bowel are most likely to cause lack of appetite.
Chronic obstructive pulmonary disease, or COPD, can cause a decrease in appetite, according to MedlinePlus. COPD is an irreversible and progressive decline in the ability to breath. Two-thirds of COPD patients are over age 65, with smoking the biggest risk factor for developing the condition, according to the Cleveland Clinic. COPD causes hormone changes, as well as an inflammation response, both of which lead to lack of appetite.
Cholecystokinin is the hormone responsible for allowing a person to feel full, or satiated, after eating. As people age, the amount of this hormone increases, and the senior will feel full with less food. Age-related changes in the senses of taste and smell can make food less appetizing. Small strokes can cause a total loss of one of these senses. Chewing problems related to tooth loss can make eating difficult. Seniors may find visually attractive food more appealing; incorporate the use of attractive plates, colorful food or fun shapes. Smaller and more frequent meals will seem less intimidating than one large plate of food. Easily chewed meals, such as chicken instead of steak, will be easier for an elderly relative with dental problems.