Changes in eating behavior, taste and food preferences and the effects of gastrointestinal hormones

Abstract

Summary: Eating behavior is a complex response to different internal and external factors and whose aim is to preserve the homeostasis of energy intake, the stability of body weight and ultimately health. Although under physiological conditions, energy intake is relatively stable over the long period, many stimuli (i.e., mechanical, metabolic, environmental, etc.) may acutely influence energy intake. To offset or minimize the effects of such stimuli on energy homeostasis, humans are equipped with neuronal complex mechanisms integrating peripheral and environmental signals. In particular, eating behavior is determined by homeostatic feeding and hedonic feeding. In the presence of changes in taste or smell, these mechanisms interact with peripheral effectors, including gastrointestinal peptides, to preserve energy intake and ultimately body weight. Aging is associated with a progressive inability of these systems to protect net food intake. Also, changes of eating behavior during disease appear to be related to the activation of a specific neuronal emergency circuit, which promotes anorexia. The persistence during evolution of the emergency pathway suggests that still unidentified component of anorexia and fasting metabolism could be exploited to enhance recovery of patients with acute and possibly chronic diseases. Keywords: Food intake, Hypothalamus, Neurotransmitters, Leptin, Ghrelin, Cholecystokinin