Review
Body Weight, Anorexia, and Undernutrition in Older People

https://doi.org/10.1016/j.jamda.2013.02.004Get rights and content

Abstract

Ideal body weight for maximum life expectancy increases with advancing age. Older people, however, tend to weigh less than younger adults, and old age is also associated with a tendency to lose weight. Weight loss in older people is associated with adverse outcomes, particularly if unintentional, and initial body weight is low. When older people lose weight, more of the tissue lost is lean tissue (mainly skeletal muscle) than in younger people. When excessive, the loss of lean muscle tissue results in sarcopenia, which is associated with poor health outcomes. Unintentional weight loss in older people may be a result of protein-energy malnutrition, cachexia, the physiological anorexia of aging, or a combination of these. The physiological anorexia of aging is a decrease in appetite and energy intake that occurs even in healthy people and is possibly caused by changes in the digestive tract, gastrointestinal hormone concentrations and activity, neurotransmitters, and cytokines. A greater understanding of this decrease in appetite and energy intake during aging, and the responsible mechanisms, may aid the search for ways to treat undernutrition and weight loss in older people.

Section snippets

Weight Loss in Older People

Although optimum body weight for survival is probably higher for older than younger adults, they tend to weigh less. This is documented in population-based, cross-sectional, and longitudinal studies9, 10 and is due to a combination of lower peak body weight and weight loss in old age. For example, in the 1997 to 1998 US National Health Interview Survey, more people aged 75 years or older were “underweight” (BMI <18.5 kg/m2; 5.0% vs 1.2%) than those aged 45 to 64 years, and substantially fewer

Weight Loss Is Associated With Poor Health Outcomes in Older People

Numerous studies have shown that weight loss in older people not resulting from malignancy is associated with poor outcomes, certainly if unintentional, but possibly even when intentional. The prospective Cardiovascular Health Study,12 for example, studied 4714 home-dwelling subjects older than 65 years without known cancer. In the 3 years after study entry, 17% of the subjects lost 5% or more of their initial body weight, compared with 13% who gained 5% or more. The weight-loss group had

Lean Tissue Loss and Sarcopenia in Older People

There are many reasons why weight loss in older people is associated with adverse effects. In some cases, weight loss is attributable to an illness, such as a malignancy, which is mainly responsible for the poor outcome. The loss of body weight after the age of 50 to 60 is disproportionately due to losses of lean body tissue, with average decreases of up to 3 kg of lean body mass, mainly skeletal muscle, per decade after the age of 50.14 When skeletal muscle mass falls too far, sarcopenia

Weight Loss Programs in Older People

Weight loss is often recommended for overweight and obese older adults in the same manner as for younger adults, and for similar increases in body weight and BMI. At any given time, a substantial proportion of older people wish to lose weight and are trying to reduce their energy (food) intake to do so. There is evidence from studies in species as varied as yeast, spiders, mice, and possibly primates that long-term restriction of energy intake by 30% to 60% compared with ad libitum intake

Cachexia in Older People

Cachexia can also contribute to weight loss and harmful undernutrition in older people. Cachexia is a complex metabolic syndrome associated with underlying illness and characterized by loss of muscle with or without loss of fat mass. A prominent feature of cachexia is weight loss, but inflammation is also a key component, with an increase in levels of inflammatory cytokines such as tumor necrosis factor (TNF), interleukin (IL)-1, and IL-6. Anorexia, insulin resistance, and increased muscle

Protein-Energy Malnutrition in Older People

Weight loss in older people predisposes to the development of protein-energy malnutrition. This is surprisingly common in developed countries, with up to 15% of community-dwelling and home-bound older people, 23% to 62% of hospitalized patients, and up to 85% of nursing home residents estimated to suffer from protein-energy malnutrition.24 Protein-energy malnutrition is more likely to develop in the presence of other “pathological” factors, which become more common with increased age (Table 1).

Protein-Energy Malnutrition and Poor Health Outcomes in Older People

In older persons, unintentional weight loss of 5% or more over 6 to 12 months is associated with an increased risk of adverse effects, whereas a loss of 10% or more is associated with a particularly high risk of protein-energy malnutrition and poor outcomes. Protein-energy malnutrition is associated with decreased bone mass, impaired muscle function, anemia, immune dysfunction, reduced cognitive function, poor wound healing, delayed recovery from surgery, and, ultimately, increased morbidity

Anorexia of Aging: Reduced Appetite and Energy Intake in Older People

All of the previously noted changes can be superimposed on, and tend to exacerbate, the effects of the steady decline in overall appetite and food intake that occurs as healthy adults age. Numerous studies have documented an age-related decline in energy (food) intake in healthy, ambulant, noninstitutionalized people of approximately 30% between 20 and 80 years.32, 33, 34, 35 For example, the NHANES III cross-sectional study reported a decline in energy intake between the ages of 20 and 80

Mechanisms Responsible for Reduced Appetite and Energy Intake in Older People

Appetite and energy intake are dependent on central and peripheral mechanisms, the latter including interrelated “intragastric” and “small intestinal” sensory and motor functions, triggered by the interaction with the nutrients ingested. There is evidence that changes at multiple sites, both central and peripheral, contribute to reduced appetite and food intake that accompany normal aging. In young people, appetite and energy intake are suppressed by distension of the distal stomach (antrum)

Diagnosis and Treatment of Weight Loss and Undernutrition in Older People

To reduce the risk of harmful weight loss, weight loss diets should be recommended to “overweight” older people with caution, and probably only if the excess weight is clearly causing functional impairment, rather than because of body weight alone. Weight loss from dieting leads to loss of lean (muscle) as well as fat tissue, and this is particularly so and harmful in older people. Such diets should therefore contain sufficient amount of protein to build up muscle tissue in older people, as has

References (84)

  • N.R. Sahyoun et al.

    Dietary intakes and biochemical indicators of nutritional status in an elderly, institutionalized population

    Am J Clin Nutr

    (1988)
  • T. Cederholm et al.

    Outcome of protein-energy malnutrition in elderly medical patients

    Am J Med

    (1995)
  • C.G. MacIntosh et al.

    Effect of small intestinal nutrient infusion on appetite, gastrointestinal hormone release, and gastric myoelectrical activity in young and older men

    Am J Gastroenterol

    (2001)
  • K. Sturm et al.

    Energy intake and appetite are related to antral area in healthy young and older subjects

    Am J Clin Nutr

    (2004)
  • R.R. Briefel et al.

    Total energy intake of the US population: The third National Health and Nutrition Examination Survey, 1988–1991

    Am J Clin Nutr

    (1995)
  • M.P. Lejeune et al.

    Ghrelin and glucagon-like peptide 1 concentrations, 24-h satiety, and energy and substrate metabolism during a high-protein diet and measured in a respiration chamber

    Am J Clin Nutr

    (2006)
  • K.L. Jones et al.

    Relation between postprandial satiation and antral area in normal subjects

    Am J Clin Nutr

    (1997)
  • B.J. Rolls et al.

    Age-related impairments in the regulation of food intake

    Am J Clin Nutr

    (1995)
  • J.E. Morley

    Androgens and aging

    Maturitas

    (2001)
  • R.N. Baumgartner et al.

    Age-related changes in sex hormones affect the sex difference in serum leptin independently of changes in body fat

    Metabolism

    (1999)
  • C.G. MacIntosh et al.

    Effects of age on concentrations of plasma cholecystokinin, glucagon-like peptide 1, and peptide YY and their relation to appetite and pyloric motility

    Am J Clin Nutr

    (1999)
  • M. Martinez et al.

    Alterations in plasma and cerebrospinal fluid levels of neuropeptides in idiopathic senile anorexia

    Regul Pept

    (1993)
  • S.S. Yeh et al.

    Geriatric cachexia: The role of cytokines

    Am J Clin Nutr

    (1999)
  • B.J. Rolls et al.

    Effects of age on sensory-specific satiety

    Am J Clin Nutr

    (1991)
  • S. Soenen et al.

    Changes in body fat percentage during body weight stable conditions of increased daily protein intake vs. control

    Physiol Behav

    (2010)
  • S.S. Schiffman et al.

    Effect of flavor enhancement of foods for the elderly on nutritional status: Food intake, biochemical indices, and anthropometric measures

    Physiol Behav

    (1993)
  • A.L. Cawood et al.

    Systematic review and meta-analysis of the effects of high protein oral nutritional supplements

    Ageing Res Rev

    (2012)
  • M.M. Wilson et al.

    Effect of liquid dietary supplements on energy intake in the elderly

    Am J Clin Nutr

    (2002)
  • J.E. Decaria et al.

    Scoping review report: Obesity in older adults

    Int J Obes (Lond)

    (2012)
  • National Health Surveys 1995, 2001, 2004–05, and 2007–2008. Canberra: Australian Bureau of Statistics (ABS),...
  • W.C. Willett et al.

    Guidelines for healthy weight

    N Engl J Med

    (1999)
  • G.W. Somes et al.

    Body mass index, weight change, and death in older adults: The systolic hypertension in the elderly program

    Am J Epidemiol

    (2002)
  • J. Stessman et al.

    Normal body mass index rather than obesity predicts greater mortality in elderly people: The Jerusalem longitudinal study

    J Am Geriatr Soc

    (2009)
  • S. Al Snih et al.

    The effect of obesity on disability vs mortality in older Americans

    Arch Intern Med

    (2007)
  • M. Thinggaard et al.

    Is the relationship between BMI and mortality increasingly U-shaped with advancing age? A 10-year follow-up of persons aged 70–95 years

    J Gerontol A Biol Sci Med Sci

    (2010)
  • C.A. Schoenborn et al.

    Body weight status of adults: United States, 1997–98

    Adv Data

    (2002)
  • W.C. Chumlea et al.

    Distributions of serial changes in stature and weight in a healthy elderly population

    Hum Biol

    (1988)
  • J.I. Wallace et al.

    Involuntary weight loss in older outpatients: Incidence and clinical significance

    J Am Geriatr Soc

    (1995)
  • A.B. Newman et al.

    Weight change in old age and its association with mortality

    J Am Geriatr Soc

    (2001)
  • L.J. Melton et al.

    Epidemiology of sarcopenia

    Mayo Clin Proc

    (2000)
  • M. Visser et al.

    Longitudinal Aging Study A. Low vitamin D and high parathyroid hormone levels as determinants of loss of muscle strength and muscle mass (sarcopenia): The Longitudinal Aging Study Amsterdam

    J Clin Endocrinol Metab

    (2003)
  • I. Janssen et al.

    Skeletal muscle cutpoints associated with elevated physical disability risk in older men and women

    Am J Epidemiol

    (2004)

    • Cited by (0)

    View full text
    Copyright © 2013 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.