How does the structure of fats enable them to hold so much energy?

Of the following given choices;

A) thalamus. B) amygdala. C) hippocampus. D) hypothalamus

The answer is; D

The region has chemicals that work antagonistically to regulate satiety and appetite. CART chemicals stimulate increased metabolism, increased insulin production and reduced appetite. On the other hand, NPY chemical reduces metabolism and increase appetite.