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Key Clinical Questions

  • image What interventions can be employed to improve nutrition in older adults?

  • image What are the recommendations for nutrition supplementation in patients with advanced dementia?

Weight loss can be classified as acute, subacute or indolent, and long-term. Weight loss is defined as a 2% loss from baseline body weight over 1 month, or a 5% loss over 3 months, or 10% loss over 6 months. In patients who reside in long-term care, weight loss is defined as 5% loss from baseline body weight over 30 days. Weight loss is associated with increased mortality as well as discharge to a skilled nursing facility (SNF).

Malnutrition has long eluded a strict and unifying definition, but the most common and generally agreed upon definition is one authored by the American Society for Parenteral and Enteral Nutrition (ASPEN) (Table 168-1). The ASPEN definition of malnutrition requires two of the following six attributes: “Insufficient energy intake, weight loss, loss of muscle mass, loss of subcutaneous fat, localized or generalized fluid accumulation, diminished functional status (measured by handgrip strength).”

TABLE 168-1ASPEN Malnutrition Definition (2 out of 6 Signs)

The term ‘failure to thrive’ is a vivid catch-all that has been used historically to describe a patient with malnutrition, weight loss and diminished functional status. In the geriatric population, failure to thrive likely evokes frailty and diminished functioning, but presentations can vary. The Institute of Medicine describes failure to thrive in older adults as “a syndrome of weight loss, decreased appetite and poor nutrition, and inactivity, often accompanied by dehydration, depressive symptoms, impaired immune function, and low cholesterol.” However, some have argued that the term ‘failure to thrive’ is too vague and nonspecific, and should be abandoned in favor of investigating the four syndromes usually associated with failure to thrive that are known to contribute individually to adverse outcomes in the older adult: functional decline, malnutrition, depression and cognitive impairment. This chapter will focus on malnutrition.


In hospitalized adults over the age of 65, 40% are estimated to be malnourished, although various studies have found the range to be 20% to 50% depending on the nutrition assessment tool used, whether billing information (ICD-9 coding) was assessed, and hospital demographics. Studies based on ICD-9 codes likely underestimate the true burden of malnutrition in the elderly, since ICD-9 malnutrition codes have notoriously been divorced from etiologies of malnutrition and largely register the degree of malnutrition based on serum albumin level, which is no longer thought to be a reliable indicator of the severity or duration of malnutrition. Increasingly, physicians have used ...

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