Do you really know though? McDonalds has lied in the past quite a bit. For example, they touted their hamburger meat as 100% beef with no additives for quite awhile, then had to fess up when the truth about Pink Slime came out.

Then when they tried to climb on the vegan/vegetarian bandwagon, they had to quickly admit that their fry shortening had beef flavoring added to it, then switch to an entirely different shortening.