Andrew Huberman· PhD
In classic experiments that date back to the '80s, this was done by what's called subdiaphragmatic vagotomy. So this means cutting off the branch of the vagus that enervates the gut below the diaphragm so that the other organs can still function because the vagus is very important, but basically cutting off the sweet sensing in the gut, still giving people the opportunity to taste sweet foods with their mouth, and they don't actively seek out quite as much of the sweet food when they don't have this gut sensing mechanism that we now know to be dependent on these neuropod cells.