...or go without sleep for 48 hours?

Food or sleep?
Just to clarify, if you go for the 'go without food' option you're still allowed to drink water (as water isn't a food), but you can't have any drinks with calories or nutrients in them such as fizzy pop or soup, as that would be sort of cheating.

So those are the two options.  Go for forty eight hours without food or forty eight hours without sleep.  Which option would you go for?