Neural and hormonal mechanisms

Neural 

The hypothalamus: Body's control centre. Critical role in regulation of eating, acting like a thermostat to initiate or stop eating. Regulates homeostasis. Can also regulate glucose levels by influencing the output of insulin and anti-insulin hormones. 

The VMH: The satiety centre. Experimental electrical stimulation reduces food intake. Malfunction may cause overeating and obesity.

The LH: Hunger centre. Secretes neurotransmitter neuropeptide T (NYP), which is associated with hunger, reduction in physical activity and a stimulant of hunger. Receptors also detect a drop in blood sugar. Damage can reduce food intake (asphasia - failure to eat).

Evaluations:

• + Hethering and Ranson - found that lesions of the VMH led to hyperphagia and obesity.
• + Wickens (2000) - rats injected with NPY into the hypothalamus will start feeding immediately, even if satiated.
• + Quaade - found that stimulating the vMH of obses people made them hungry, similar to studies on rats. 
• - Marie et al - genetically manipulated mice so they didn't make NPY and they found…