A bid by Health Secretary Robert F. Kennedy Jr. to label pesticides as a potential cause of U.S. health woes has attracted pushback from some White House and agency officials who are concerned the move would disrupt the food-supply chain, according to people familiar with the debate. Kennedy, who is spearheading a coming report to “Make America Healthy Again,” wants to highlight what he views as the deleterious impact of pesticides, people familiar with the matter said. He previously...