Every day, doctors write prescriptions for medications that will treat various ailments in their patients. Those prescriptions, though, come once the patient is already sick. In an effort to stop disease before it starts, some researchers are pushing for policies and programs that would let doctors prescribe healthy foods and insurers to cover them—actively helping patients shift to a health-promoting diet. These types of programs work: Subsidizing fruits, vegetables, and other healthy foods under Medicare and Medicaid could prevent millions of cases, as well as deaths from cardiovascular disease, according to a new model. It would prevent hundreds of thousands of diabetes cases, as well, and save billions of dollars in healthcare costs.