Whats the purpose of the vagus nerve?
Dr. Lustig: The vagus nerve is the energy storage nerve, that’s its job. It does it in five different ways. First, stomach to the brain, this is part of the hunger signal. It’s not the complete hunger signal, but it’s half of it, so that’s part of why you get hungry, the vagus nerve from the stomach to the brain tells you the stomach is empty you need to eat. Second, brain to stomach, that’s hydrochloric acid secretions, which helps digest the food. Third, brain to the intestine, which moves the intestine around the peristalsis, that helps you absorb the food. Fourth, brain to the fat tissue itself, which actually improves insulin sensitivity at the level of the adipose tissue in order to get insulin to move more energy into fat. And fifth, brain to the pancreas, which tells the pancreas to release more insulin in order to shunt more sugar to fat. Every single thing the vagus nerve does is designed to get energy into your fat cells. When you cut the vagus nerve, what happens to the ene
