My wife is a neurosurgeon in residency and she absolutely works 90-~110 hours just about every week. She barely sleeps and eats one or two big meals a day (almost always ordered from Seamless), we have to live within a couple blocks of the hospital, and I just don't see how she would survive on her own if I wasn't around as far as food/laundry/etc.. is concerned -- I think that answers all of your questions.