Individuals above the age of 60 years constitute the elderly. However the increasing number of healthy and active people among the elderly has led to the need for more defenitive age groupings. Thus the specific age groups of 65-75, 75-85 and older are often referred to as the young old, old and the oldest old respectively. Today the elderly constitute about seven percent of the total population and the projected figure is ten percent by 2016. Hence health and well being of the elderly is given more importance and has paved way for a specific field of study called 'Geriartric Nutrition'.
Aging is a irreversible biochemical change that occurs throughout an individuals life cycle and continues until death. Genes are the major determinants of nature of aging. Health and good nutrition may delay the process of aging. Aging varies among individuals depending on their nutritional status and living environmental conditions.
In old age, the nutritional status is determined by the state of nutrition of an individual cell. Conditions like dietary deficiency, improper digestion and absorption, insufficient distribution of nutrients, accumulation of excess waste products lead to poor nourishment of cells.
With increasing age, cell functioning is slowed down and the response to
harmones and synthesis of enzymes decreases. These changes are associated with
a decrease in the number of functioning cells. Since the cells are
interdependent, if one cell dies, others of the same or different organ lose
their ability to function resulting in malfunctioning of the organ. This in
turn gradually affects the total body function leading to death.