Undernutrition in the Elderly: A Physiological or Pathological Process?

Many studies hâve shown that there is a progressive décline in both energy intake and energy expenditure with increasing âge, with altérations in body composition such that the proportion of adipose tissue increases at the expense of the lean body mass. Nutritional recommendations for the elderly are based on the assumption that thèse changes are detrimental. Thus, the recommendations hâve been designed in gênerai to reverse the changes and restore the body composition and nutritional requirements to that of the younger âge groups. Other considérations suggest that this is not necessarily correct. Following the concept of Cannon that there is inhérent "wisdom" in the body's metabolism and the comment of Shock that "aging is not a disease," the changes found in the elderly may in fact reflect their différent physiological status and be an adaptive response designed to promote longevity. The aim of this chapter is to suggest that the "undernutrition" ofthe elderly—far from being a pathological process—may rather be an attempt to slow the progress of various disease processes, in particular atherogenesis and tumorigenesis.