is this english ??
It should be: They will be able to eat.
Exactly! And they did not accept it
They will be capable to eat is better English!
No it isn't. "They will be capable of eating" is a proper sentence. They may be post operation or may be toddlers.
Whether '...of eating' is correct English, is besides the point (it's correct btw)...I just thought 'capable to eat' was more commonly used, maybe they should accept that too?