ABSTRACT
Nutrition plays an increasingly important role in health and disease as we age. The prevalence of protein-energy malnutrition (PEM) increases with age and frailty and is associated with poor outcome. Nutrition-related disorders in Western societies more often conjure images of nutritional excess and obesity rather than malnutrition. Nonetheless, with advancing age, multiple well-documented age-related conditions converge to put the geriatric population at risk for nutritional deficits (Morley and Silver 1995, Thomas and Morley 2001). Weight loss in the elderly may not receive the attention and sense of urgency it commands, in part due to the compulsion during earlier adult life to achieve just such a weight loss. While undernutrition may be the cause or the end result of a specific disease process, it more often represents a single
facet of multiple complex interacting physiological changes, resulting in progressive functional decline, as seen in anorexia of aging and adult failure to thrive (Morley and Silver 1985). It is estimated that up to 16% of Americans over the age of 65 consume less than 1000 kcal/day, and 30 to 40% of individuals over the age of 75 are at least 10% below their ideal body weight (Third National Health and Nutritional Examination Survey 1994, Wakimoto and Block 2001, Joshi and Morley 2006). Overt malnutrition is encountered in 5 to 12% of ambulatory community-dwelling elderly, 20 to 37% of home-bound elderly, and 32 to 50% of hospitalized older adults. In the long-term-care setting, the prevalence of undernutrition may be as high as 85% (Drinka and Goodwin 1991, Zulkowski 2000, Johnson et al. 2002, Abbasi 1995, Abbasi and Rudman 1993, Ritchie et al. 1997, Garry et al. 1984).
