Malnutrition

In community-dwelling older people, dietary and nutritional adequacy depend on the ability to purchase and prepare food, and to eat independently. Among those living in institutions, the availability of dietary assistance when Table 1 Dietary Reference Intakes (DRIs) for persons age 70-plus (NAS, 2000) SOURCE: Author needed and appropriate meal presentation are additional nutrition considerations. The presence of disease or chronic conditions such as mobility problems, depression, or dementia, or medications with an effect on appetite can lead to a worsening nutritional situation. Aging adults, particularly those dependent on others, have been recognized as a group at nutritional risk (Sullivan and Walls). In sum, inadequate food intake and/or increased nutritional requirements can lead to malnutrition, and poor nutritional status is considered a key determinant of morbidity and mortality in elderly individuals (Sullivan and Walls).

In older people, most malnutrition is the consequence of decreased or inappropriate food intake. Common causes are loss of appetite, dysphagia, oral health problems such as poor dentition or dryness of the mouth, depression, polymedication, inappropriate use of restricted or modified diets, physical and cognitive impairments, dementia, slowness in eating, inability to feed oneself, inadequate assistance in eating, sub-optimal dining environment, and limited menu choices (Keller; Sullivan et al.). In addition, sensory problems, such as olfactory or taste dysfunction, may affect desire for and appreciation of food, thereby diminishing intake and increasing risk of chronic diseases. Finally, it has been shown that people with adequate dental status (especially those with natural teeth) have better dietary patterns than those with ill-fitting dentures or who are toothless, and this contributes to higher protein, vitamin, and mineral levels, and lower fat and cholesterol intakes. On the other hand, obesity in elderly people may be related to dietary imbalances, such as insufficient fruit and vegetable intakes and excessive meat intakes, or consumption of easily prepared, easy-to-chew, empty-calorie foods, which may contribute to or exacerbate health problems.

Weight loss, which signals an imbalance between energy intake and expenditure, is a well-known marker of nutritional status in older people. It leads to decline in functional abilities, increased risk of hip fracture, and early institutionalization and mortality, independent of coexisting disease states. Furthermore, this phenomenon has been observed in studies of widely different groups of elderly persons, ranging from those in good health (Harris et al.) to hospital patients (Franzoni et al.) and to individuals who require home care in order to continue living in the community (Payette et al.).

Loss of skeletal muscle mass, or sarcopenia (Rosenberg) is observed with aging even in well elderly people at a stable, healthy weight and the obese (Melton et al.). Sarcopenia is associated with decreased functional abilities and increased risk of falls among very old people (Rosenberg). This lowers energy needs (Poehlman et al.) and increases the likelihood of mobility problems and fractures resulting from osteoporosis (Melton et al.). In addition, it appears that older people with both sarcopenia and obesity are more likely than their nonobese sarcopenic or nonsarcopenic counterparts to suffer from physical disabilities and problems with balance and gait, and to experience falls (Baumgartner).

It now appears that many diseases associated with aging, including heart disease, diabetes, and infectious diseases, are associated with weight loss and wasting, or cachexia (Roubenoff and Harris). Intensive nutritional intervention has the potential to halt and reverse weight loss, and may even contribute to weight gain (Franzoni et al.), which could delay mortality in elderly chronic care patients (Keller). Indeed, it has been shown that women who maintain a consistent body weight after menopause are less likely to suffer fractures than those who systematically lose weight (Cummings et al.).