science

But the most novel and surprising thing that researchers have observed is that when a certain group of neurons in that same nucleus is deactivated, specifically those that project to the jejunum, a part of the small intestine, the length of the microvilli in the intestinal wall is shortened, which reduces its surface area and thus the place in whose blood capillaries fat absorption occurs. The brain thus regulates this absorption by controlling the length and surface area of the intestinal spaces in which it takes place.

Huh, so your intestines can stretch to control absorption rate, cool!