What you feel is important may not be what the director feels is important.
I don't really need a lot of help from a director.
I think my anorexia was to do with being a teenager, not being in films.
As a teenager, my favourite rejection was, 'She looks too healthy,' which of course translates as, 'She needs to lose weight.'
I once ate McDonald's three times in one day.
Unless it's a specific accent, or something about physicality you have to change, I am generally not such a conscious actor.