Food in America has long served as a proxy for national identity. “The red, white, and blue Popsicles you licked as a kid?

From McDonald’s to Sonic, these fast-food chains rely on processed cheese—not the real deal—for their burgers.

Dr. David Kessler, who led the FDA and later ran Operation Warp Speed, said obesity rates have jumped from 13% in the 1960s ...