A. Limbic system: Respobnsible for feelings and memories. Processes informations about former experiences with food and rewards. Can cause one to eat more or less.
B. Hypothalamus: Processes signals by intestinal hormones and fat and sends its own signals. MCH and NPY block pain signals, have a calming effect, and encourage eating. Other signals, like MSH, decrease the appetite. The appetite of a person is determined by the balance between these signals.
C. Afferent vagus nerve: Send signals from the intestine to the brainstem.
D. Genes: Can influence the effects of hormones. A gene variation can influence the appetite of a person and cause them to eat more or less.
E. Stomach: Produces hormones like ghrelin, which signalizes hunger.
F. Pancreas: Secretes various hormones, e.g. insulin, incretin, and amylin, which signalize that less should be eaten.
G. Duodenum: Part of the intestine that produces GLP1 and CCK, that also signalize that the food intake should be reduced.
H. Intestine: Secretes PYY 3-36, a hormone that tells the hypothalamus to reduce the appetite.
I. Fat tissue: Secretes the influential hormone leptin, which affects the hypothalamus and long-term inhibits the food intake.
J. Environmental factors: Increased marketing and availability of (especially high-calorie and processed) food.
‘Big Picture: Food and Diet’ (2011)
