Board Thread:The Flash episode discussions/@comment-75.148.114.97-20150401203819/@comment-103.26.193.28-20150619110307

It might be affected by the fact that Eobard's powers are on/off. While his powers are available, he might be using any of the suggested methods on this post to hide his appetite. While they aren't,  he probably doesn't eat too much.

Also, in the comic, Barry doesn't eat so much. His appetite and hunger weren't really affected by the speed; rather, Wally West's was. TV Barry's appetite might've been borrowed from pre-Flashpoint Wally West, who was constantly munching down.