Satiety and the anorexia of ageing.

The 'anorexia of aging' refers to reduced appetite and energy intakes observed in some older adults. Satiation (the process that leads to the termination of eating, which may be accompanied by a feeling of satisfaction) and satiety (the feeling of fullness that persists after eating, potentially suppressing further energy intake until hunger returns) are important factors in the control of appetite and energy intake, and there is evidence that some aspects of satiation and satiety are altered in older adults. Factors affected include gastric emptying, which could affect satiation, and levels of gut hormones which could affect satiety. Sensory specific satiety also appears to be reduced in older subjects. This might be important in the anorexia of aging and dietary strategies could be used to reduce satiety and encourage an increased energy intake. However, many other factors may affect the anorexia of aging and it is important to understand these in order to help those at risk of malnutrition.