The beef they use here in the UK, is made by a firm called Mckey. Not only do I know its 100% beef but I used to get bags of frozen burgers from someone who worked for Mckey and used to eat them when I was on my ass doing my post grad.
I even had someone look at one for me ( a food scientist with time on their hands) and its what it says it is. There is no fuckin way MAFF or probably the FDA would let them get away with saying 100% beef when it wasn't not in such a high profile firm.
I mean ok the food is still pretty shitty, hydrogenated fats, sugar, salt, lard etc etc, its just the burgers at least in UK are 100% beef with a bit of salt and seasoning. I'm only disagreeing on the beef thing, that is all, not saying the food is good, it never is.