Drinking more water could produce a satiated feeling in the brain

New research by the Society for the Study of Ingestive Behavior shows that people whose stomachs are more physically full feel more satiated during and after a meal.

The results came through studying simultaneous stomach MRIs and brain fMRIs as participants drank milkshakes and various quantities of water. When the volume of the stomach was higher (and it was therefore physically stretched to be bigger than usual) participants felt more full. Plus, the insula, an area of the brain related to satiation, was more activated when there was more water or milkshake in the participants’ stomachs.

The study, performed at a university in the Netherlands, is set to be presented at the society’s annual meeting in Portugal. It recorded the brain and stomach scans and reported feelings of the 19 participants over the course of two appointments.

When they drank 350 milliliters (about 12 ounces) of water after drinking a milkshake, participants said (and their brain scans showed) they felt fuller than if they had only had a 50 milliliter (about 2 ounces) glass of water after the milkshake. Brain scans showed more activation in the insula when the stomach was more distended, according to the recorded images of both types of simultaneous MRIs.

It was not previously known that increased water in the stomach increased the activity in this part of the brain.

The study’s authors conducted the research as part of a European initiative to promote healthier eating habits. This research could be used to advocate for drinking more water as a way to produce a more satiated feeling without eating more.