Abbott Laboratories launches a high-protein shake to help people maintain muscle mass while pursuing weight loss, one of a wave of such products expected to come to market amid strong demand for new weight-loss drugs. Companies including Abbott and Nestle have said in recent months that they would develop companion products for people trying to shed pounds. Abbott’s shake, introduced under the company’s new Protality brand, is intended for adults who may have a hard time getting enough protein and other essential nutrients to support muscle mass while consuming fewer calories, the company says. Marketed in milk chocolate and vanilla flavors, it will be sold online and in stores like Walmart and Kroger, Abbott says.