McDonald's burgers are 100% beef. What's the problem? If the bun and other parts of the burger are ultra processed, whatever that means, well, that's the same for their chicken sandwiches, right? If the problem is the salt or seasonings, why not ban ads for salty burgers over a threshold or burgers with the specific problematic seasonings?
Salt is not particularly a problem unless someone has a genetic predisposition to hypertension or doesn't drink enough water.