Well, rather amusingly I don't have a Maccy D's within a 20 minute walk radius. For Central London (EC1/N1) that is a
major dead zone. However just 2 minutes walk away are 2 rival kebab shops opposite each other, both of which serve lovely Donor meat that apparently came from lambs. The thing about Donor meat is that it appears to consist entirely of internal organs glued together with fat. Anything that is normally only bought by drunks (Special Brew, Cider, Kebabs, etc) probably is better off avoided.
Oh, and we also have the "Best American Pizza Company". Which is run, rather predictably, by Turkish people...