Yeah man ur body isnt gettin what it needs too function if u dont have something in ur system...It is kinda of a DUH question but even i had too find out that shit the hard way at a young age.. didnt eat for like two days and went too werk and all of a sudden i got hella light headed and my knees start wobbling like i couldnt get no coordination in em...sooon after... tunnel vision.. thats when u kno u bout too pass out..