Could it be considered abuse? Shoot anything could be considered abuse. But the thing is... how can you monitor such a thing?
I mean yeah the obvious way would say... look at the kid BUT... what about those kids with thyroid issues? Those kids get big no matter what is done. It isn't because of overeating but because of something medical and to punish those parents would be absurd. There are some that seem "normal" looking but are being overfed as well. So... it isn't about overeating but more about proper eating and exercise. Like is the parent just allowing the child to be watched and babysat by the TV and video games all day long or are those parents able to take the time out to spend some time with their kids, to take them outside, let them go outside, or anything of that nature.
So I don't think its really as clear cut.