Activin, a hormone produced by the testes and ovaries, has been associated with the wasting syndrome in transgenic mice. A diminished sense of smell and taste may decrease the pleasure of eating, but changes in taste appear to play a minor role in decreased food intake, even though many elderly persons complain that food does not taste as good as it used to. Changes in taste are variable and are often associated with lifelong cigarette smoking, poor dental hygiene, and disease. Dysphagia due to a stroke, another neurologic disorder, or esophageal pain caused by candidiasis may lower food intake, as may dental problems and xerostomia. Continuous tremors from such conditions as Parkinson's disease may cause weight loss by markedly raising the metabolic rate.
Depression is one of the most common reversible causes of weight loss in the elderly.
Depressed elderly persons are more likely to lose weight than depressed younger persons. Some very old persons may stop eating because they have lost the joy of living but are not clinically depressed. Loneliness can diminish the desire to prepare meals. Poverty can also cause low food intake. Problems with shopping and food preparation may result in insufficient food being available in the home.