• Posted April 25, 2026

Your Internal Signal to Stop Eating is More Complex Than Previously Thought

When your belly is full, your brain tells you to "stop eating."

But how that signal works is more complex than scientists have understood — and they hope their discovery that it comes from an unexpected source could lead to new treatments for eating disorders and obesity.

"This research changes how we think about these communication circuits," said researcher Ricardo Araneda, a professor of biology at the University of Maryland.  

He is part of a team that recently published its findings in the Proceedings of the National Academy of Sciences. 

Scientists have long thought that the brain knows it’s time to push the plate away almost entirely because of signaling cells called neurons.

The new study suggests that it’s far more complicated than that, involving other types of cells in the brain.

"What surprised us was the complexity of it," Araneda said in a news release. "To put it simply, we found that tanycytes 'talk' to astrocytes, and then astrocytes 'talk' to neurons."

Tanycytes are specialized brain cells that monitor a body-fueling sugar called glucose as it moves through the fluids that cushion the brain and spinal cord.

After you eat, glucose levels rise. And that release prompts tanycytes to release lactate into nearby brain tissue. Researchers used to think lactate directly signaled neurons involved in appetite control. 

"But we found that there was an unexpected middleman in that conversation, astrocytes," Araneda said.

Among the most common cell types in the brain, astrocytes have long been seen as helper cells for neurons. The new study shows they take on a more direct role.

That’s because astrocytes detect lactate. In turn, that prompts release of a chemical messenger that signals neurons to suppress appetite. Simply put, this cellular communication is what tells you you’re full.

Araneda thinks it could be a promising avenue for treating appetite-related conditions.

That’s some time off, however. 

This research was conducted in animal models, and results of animal studies often differ in humans. 

But there’s reason for hope. Because tanycytes and astrocytes exist in all mammals, the same mechanism could be at work in people, researchers say.

Next step: Investigating whether altering the receptor that allows astrocytes to detect lactate influences eating behavior. No existing drugs directly target this pathway.

"We now have a different mechanism where we might be able to target astrocytes or specifically this … receptor," Araneda said. "It would be a novel target that may complement existing therapies like Ozempic, for example, and improve the lives of many who suffer from obesity and other appetite-related conditions."

More information

The Cleveland Clinic explains how to tell when you’re full.

SOURCE: University of Maryland, news release, April 6, 2026