My friend Tony just lost three toes. Two more may be amputated soon. The cause of this tragedy was type 2 diabetes, even though it is a manageable and often preventable disease.

Tony is not alone: According to the U.S. Centers for Disease Control and Prevention (CDC), about 29 million Americans suffer from diabetes; worldwide, the number is more than 400 million, reports the World Health Organization. All are at risk for amputated limbs, heart disease, stroke, blindness, and other serious complications.