We all know that sugar can make you fat. But we eat it anyway because it’s really good.

So what if we were to tell you sugar can also make you dumb? Would you put down your Big Gulp and step away from your Snickers?

Researchers at UCLA trained lab rats to navigate a complicated maze. Then they fed half of the rodents a steady diet of high-fructose corn syrup for six weeks. When that was over the rodents who got the sugar high couldn’t remember how to complete the maze, whereas the rats who ate a more normal diet were still able to.

After running brain scans on the rodents, the researchers concluded that too much sugar changes their insulin levels, which in turn affects the brain’s ability to function efficiently.

“Because insulin can penetrate the blood-brain barrier, the hormone may signal neurons to trigger reactions that disrupt learning and cause memory loss,” one of the researchers explained.

Or, in layman’s terms “Sugar make stupid.”