Why are there so many chewy bits in a McDonald's double cheese burger?

That is because McDonald's uses 100% beef but any parts they can get of the cow. Yahoo News said that they use the same beef that they use to make cat food. That is why I don't eat fast food hamburger anymore. Taco Bell hamburger is only 30% beef. The FDA said in order for fast food restaurants to claim it as beef they have to use at least 35% beef. That is why Taco Bell had to up the beef in their meat recently. Seen all over the news months ago.