A new class of weight-loss drugs is giving researchers and regulators insight into the biology of weight gain and the complex connection between the gut and the brain, seemingly marking the “beginning of a revolution” in the way that weight is controlled using medicine and digital technologies, FDA chief Robert Califf said during an episode of the Conversations on Health Care radio show that aired Tuesday (March 21). Califf’s comments come as physicians, weight-loss app developers and health care experts...