This clash over the science of obesity comes in a period of rising efforts to tax sugary drinks, remove them from schools and stop companies from marketing them to children. In the last two decades, consumption of full-calorie sodas by the average American has dropped by 25 percent.

“Coca-Cola’s sales are slipping, and there’s this huge political and public backlash against soda, with every major city trying to do something to curb consumption,” said Michele Simon, a public health lawyer. “This is a direct response to the ways that the company is losing. They’re desperate to stop the bleeding.”