By JONEL ALECCIA, AP Health Writer Packaged foods in the U.S. will have to follow new rules in order to call themselves “healthy,” according to changes finalized Thursday by the Food and Drug Administration. It’s an update of the agency’s definition originally devised 30 years ago. The move is aimed at helping Americans navigate food labels at the grocery store and make choices that are aligned with federal dietary guidelines — in hopes of reducing rates of diet-related chronic disease, the FDA said. Under the rule, products that claim to be “healthy” must contain a certain amount of food from one or more food groups such as fruit, vegetables, grains, dairy and protein.