Oh, sorry. It was Zeff.
I stated it was kid Sanji so I thought people would know Zeff.
Anime it was chain, Manga it was an eaten leg.
Is it possible to eat your body parts?
If you have the guts to do it, will it keep you from starving?
Well in the long run it'd be pointless as the muscle and fat would be broken down by the body to be used to keep you alive anyway. There wouldn't be any energy-rich tissue you'd miss out on eating left anyway. However, if you need that quick energy boost of if you're just really hungry I advise you to eat your leg.
Take it from me, I'm a doctor.
! Or wait, was I a tv show psychologist?