Many of us may not realize that body fat can be metabolically healthy — or the reverse — no matter what someone’s weight or shape.

“Healthy fat is not about the amount of fat” someone carries, said Jeffrey Horowitz, a professor at the University of Michigan, who studies exercise and metabolism. It is about how well that fat functions, he said. “A person who has healthier fat is much better off than someone with the same body fat percentage whose fat is unhealthy.”

What principally differentiates healthy from dysfunctional fat, Horowitz continued, is the size of the fat cells. “The more small fat cells, the better,” he said.

And notably, you don’t have to lose weight or fat to make the body fat you already have metabolically healthier.