Why Seek Sugar With a Numb Mouth?

On The Tim Ferriss Show, neurons in the mucosal lining of the gut sense fatty acids, amino acids, and sugar. They like fat. They like amino acids for the umami flavor and because amino acids are vital to protein repair, metabolism, and protein synthesis. They like sugar.

When you eat something with fatty acids, amino acids, or sugar, the neurons, which are part of the vagus nerve, send a signal up to a little cluster of neurons in the neck called the nodose ganglia. The nodose ganglia then stimulates deep brain centers to release dopamine.

Data from Duke University show the drive does not depend on taste. Even if you numb the mouth, or gavage a person or an animal and put the substances into the stomach, you will seek more of the foods. You seek sugar, amino acids, and fat more when you ingest the foods, independent of how they taste.