Effects of aging on body weight

What effect does aging have on body weight?

• Aging is associated with changes in body composition that may be influenced by the endocrine milieu and can have important endocrine/metabolic consequences.
• In general, body weight increases with advancing age until about age 60 years; thereafter, it stabilizes and then declines after age 65 to 70 years.
• This may be attributed to improved survival of adults without obesity and/or a “die off” effect in the heaviest individuals during middle age.
• However, the reduction in body weight in older adults, whether intentional or unintentional, appears to be associated with an increase in mortality, morbidity, and disability.
• Indeed, there is a well-described obesity paradox in older adults, wherein higher body mass index (BMI) is associated with lower overall mortality, and weight loss is associated with greater mortality compared with weight stability.
• The causes for this are not clear, but it is possible that any sustained weight loss may, in fact, be unintentional, as intentional weight loss is difficult to maintain.
• Weight loss, in the face of illness or disease raises cytokine levels and may predispose to a disproportionate loss of weight as lean mass (muscle mass). This weight loss exacerbates age-related sarcopenia (loss of muscle mass and strength) and leads to a catabolic state.
• It is also possible that the apparent obesity paradox of aging is related to the time of onset of obesity in older adults, with obesity beginning at a young age or in middle-age being associated with untoward consequences, and obesity beginning at an older age being less dangerous.
• Interventions in these two potentially heterogeneous groups might also be expected to produce different health-related outcomes, but these have not yet been studied.

Body Composition Changes with Aging