It's funny you bring up McDonald's and Coke, because those are perfect examples to make RFK's point.
Before the early 1990s, the McD fries were made with beef tallow. Come to find out, beef tallow actually wasn't nearly as unhealthy as people made it out to be, since it is a natural ingredient. If anything, the heavily processed oil they used now is increasingly proven to be more cancerous than beef tallow.
Similar situation with Coke. For years, it was made with pure can sugar (again, a natural ingredient). Now, it's made with heavily processed high fructure corn syrup which is also increasingly proven to be more cancerous.
The real issue has always been moderation of these foods. Americans, sadly, are gluttons (myself included).