Info on the involvement of the vagus nerve...courtesy Melbourne Bariatrixs
http://www.melbournebariatrics.com.au/gastric-melbourne-bariatics-peninsula.html
Decreased drive to eat (less hunger), slow eating, smaller meals, longer sense of fullness
The band gently squeezes the upper stomach and this creates 2 effects: The stomach is narrow, and the Vagus nerve is squeezed. The stomach being narrow has the effect of allowing food to pass only very slowly, It is like blocking off a couple of lanes on a freeway: now the cars have to drive slower and they get to their destination slower. In fact, some people can’t get on the freeway, as there isn’t enough room. And so the food goes down slowly, you have to eat less food because thee is nowhere for it to go. You eat slowly and eat small meals. So you eat your meal slowly, because if you don’t things will block up and there may well be vomiting. The Vagus nerve is the nerve that (apart from many other functions) controls the stomach and also tells the stomach when you are full. As you eat, the Vagus nerve detects that the stomach is stretching and as this increases sends a message to the brain to stop eating, the stomach is full. With the band, this squeezes the vagus nerve all the time, and more so when you are eating. This effectively tells the brain that the stomach is always pretty full and to stop wanting to eat. In other words, you fell less or no hunger, and feel full very early in the meal, and this fullness then, coupled with the decreased hunger in the first place, results in long lasting, strong sense of fullness.