Abstract

During the past decades, the world’s population has continued on its remarkable transition from a state of high birth and death rates to low birth and death rates. As a result, the number of elderly people, and particularly of the very elderly people, is increasing throughout the world. This demographic change has profound implication for medical and health care systems. As more people live to advanced old age, it is important to understand the chronic diseases and health problems which affect them from a physiologic standpoint. It has been well established that nutritional status has an important role on functional capacity and health status of the elderly people. Recently, there has been momentous development in perspectives of the metabolic mechanism that associated with ageing. As person live longer, the function of organ system decrease and the functional reservoir against external stress is depleted simultaneously. The concept of ‘homeostenosis’ emerged to account for the changes, and it is characterized that progressive constriction of homeostatic reserve in every organ system. Comorbidities like hypertension, diabetes mellitus, dementia, depression, and physical limitations are very common in the elderly, and they are often troubled with decreased function of digestive systems and sensory organs. Furthermore, many elderly people have suffered from poverty and social isolation. Accordingly, the older are more prone to malnutrition or undernutrition. In addition, the combination of the mentioned problems with homeostenosis will lead to metabolic derangement, like insulin resistance and visceral fat accumulation. This process makes a deleterious effect on their comorbidities or physical function; consequentially it triggers and exacerbates frailty in the elderly. In this review, we describe the mechanism of metabolic change, and appropriate nutritional supply for the elderly.

• Keywords: Aged, Metabolism, Homeostasis, Nutritional therapy