Coffee consumption, both caffeinated and decaf, is consistently linked to better metabolic health, including a lower risk of type 2 diabetes. There are plausible mechanisms behind this association. Coffee’s polyphenols, including chlorogenic acids, and caffeine can activate AMPK, a cellular energy sensor involved in fat burning and glucose regulation. Experimental research also suggests chlorogenic acid can suppress glucose production in the liver. Much of this comes from cell and animal studies, so it helps explain the association, but doesn’t prove that coffee prevents diabetes in humans.