Table 1.

General factors contributing to anorexia of aging and malnutrition.

GASTROINTESTINAL CHANGES

decreased appetite and thirst decreased sense of smell and taste (diminished food intake) decline in saliva secretion (reduce the ability to dissolve foods) poor dentition abnormalities in gastric motility (loss of gastric compliance and more rapid antral filling, delayed gastric emptying; proton-pomp inhibitors can further delay gastric emptying) constipation (due to immobility, chronic volume deficiency, low-fiber diet, and inadequate hydration)

SYSTEMIC CHANGES

hormonal changes (ghrelin, cholecystokinin, peptide YY, leptin) presence of chronic low-grade inflammation (increased circulating levels of interleukin 1, 6, and tumor necrosis factor alpha) leading to reduced food intake reduced energy requirements (reduced physical activity, reduced food intake)

GERIATRIC SYNDROMES

multimorbidity: acute diseases (can lead to temporary anorexia resulting in loss of weight, which often cannot be compensated), chronic infections (congestive heart failure, chronic obstructive pulmonary disease, Parkinson's disease), tumor cachexia, pulmonary cachexia, renal cachexia) depression and dementia (loss of appetite and reduced food intake) drug-induced anorexia polypharmacy social isolation functional impairments in activities of daily living (ADL) (reduced food intake and loss of appetite) sensory and motor impairment (e.g., problems in eating by oneself, difficulty in getting foods, and lack of cooking skills)