Hello xue'er, "eat one's head off" is a colloquial way to say 'to eat excessively', Since "好吃懒做" means eat a lot but never works , then "to be gluttonous and lazy" refers more to it.

Where I live, "to eat one's head off" could mean "to eat a lot." However, it is confusing if used out of context. It would be better to say "to be gluttonous and lazy." This sounds a little more educated and gets the point across.