Nestle Supplement 2

NUTRITION AND THE OLDER PERSON on body weight and health. In addition to age-related shifts in the proportion of fat mass to fat-free mass, the distribution of fat also changes with aging. Intra-abdominal fat increases to a greater extent than subcutaneous or total fat.This redistribution, along with increases in intramuscular and intrahepatic fat, is associated with adverse health outcomes, such as insulin resistance and other components of metabolic syndrome.17,18 Fat mass is directly correlated with many of the adverse health effects of obesity,19 while fat-free mass, in particular muscle and bone, is positively associated with strength, physical function, and overall quality of life.20 Assessment of body composition is particularly important in determining if an older individual will benefit from intentional weight loss and, if so, which strategies will most effectively target fat loss while maintaining or increasing lean mass. Direct measures of body composition require significantly greater resources than simple anthropometric measures.Thus, most screening indices and categories of weight status are based on height and weight. Relatively clear-cut standards exist to identify adults and children at risk for underweight and overweight/obesity and the associated adverse health consequences. Two commonly used methods of defining “desirable weight” are calculation of body mass index or BMI (weight, kg/[height·m2)21 and comparison to Metropolitan Life Insurance Tables.22 These tools enable healthcare providers to educate and instruct adults, adolescents, and children to achieve a body weight appropriate for height and within a range associated with low morbidity and mortality. A serious limitation of these standards is that they do not represent ideal body weights for older adults and the elderly. The Metropolitan Tables are based on populations of men and women ages 25–59, while BMI, an indicator of body fatness, defines weight status relative to the relationship between body fat, disease, and death for adults 20 years and older. While BMI is interpreted differently for children and teens (age and sex specific), a similar distinction is not made for older adults, although it is recognized that, at the same BMI, older people tend to have more body fat than young adults.7,23 Although BMI underestimates body fat in older adults, it may overestimate health risks associated with overweight status in the elderly.7,24 Several studies8,25 observed that minimum mortality occurs at a higher BMI in older subjects compared to younger subjects while some even suggest that high BMI does not predict mortality in persons age 70 years and older.6 In fact, several studies report that weight loss, both intentional and unintentional, is predictive of increased all-cause mortality.9,26–28 Extremes of both low and high body weight are associated with higher mortality rates in the general population as well as in older adults. Interestingly, in a study of estimated excess deaths across a range of BMI categories, the majority of excess deaths associated with obesity occurred in individuals younger than 70 years whereas the vast majority of excess deaths associated with underweight occurred in those individuals greater than 70 years of age.25 Underweight or “thinness” is defined by a BMI of less than 17 in children and adolescents29 or lower than 18.5 in adults.3 Less than 2% of the US adult population (25–59 years) fits this criteria whereas ~ 3% of adults 60 years and older are underweight by this definition.25 Analyses of earlier data sets provide higher estimates suggesting that 9%–17% of the population is underweight.3 Underweight in children and adults is often indicative of disease or some disorder including eating disorders. Correction of the underlying problem should improve weight status of the individual. Elderly who present with low body weight may have health conditions that contribute to weight loss or they may simply lack appetite due to decreased physical activity, drug interactions, dentition difficulties, and/or decreased sense of taste and smell.4,11 In any case, frailty impairs quality of life and increases risk of falls, fracture, and mortality.30 Galanos and colleagues31 examined the relationship between BMI and the ability to perform activities of daily living in free-living elderly subjects. Functional impairment was significantly greater in those individuals with either a low BMI or a high BMI. In an Italian cohort of hospitalized patients,8 a BMI 27 kg/m2 was not related to risk of mortality. Frailty in older women, as identified by unintentional weight loss, weakness, self-reported poor energy, slow walking speed, and/or low physical activity, increased the risk of recurrent falls, hip fracture, nonspine fractures, and death.26 This relationship persisted even in individuals categorized as frail despite a relatively high BMI (> 30 kg/m2), underscoring the primary need to consider muscle mass in determining a healthy body weight. Sarcopenic obesity characterizes a unique weight status observed in the elderly in whom an unhealthy excess of body fat is accompanied by detrimental loss of muscle and fat-free mass including bone.32 More than 65% of all young and middle-aged adults are overweight or obese. Overweight and obesity are defined by BMI values of > 25 kg/m2 and > 30 kg/m2, respectively.1 Ample evidence exists documenting the health risks of obesity in these populations. These include cardiovascular disease (CVD), type 2 diabetes, hypertension, arthritis, and certain cancers.21,33 Population studies consistently show DECEMBER 2007 • 19

Table of Contents Feed for the Digital Edition of Nestle Supplement 2

Nestle Supplement Table of Contents Introduction to Weight Loss in Older Persons Diagnosis and Management of Oropharyngeal Dysphagia in the Elderly The Danger of Weight Loss in the Elderly Nutrients and Frailty

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