6.5-7.5 hours of sleep a night on weekdays
7-9 hours a night on the weekends
I try to go to bed by 11 every night, and on weekends get up before 9. Having a night owl of a roommate, this isn't always easy.
In week days where I work I get 6-9 hours per day, but in the weekend where I'm out a lot with friends partying and what not, I probably get 2-5 hours day. It's impossible for me to sleep after I've been drunk, I'm not tired after 3-4 hours of sleep when it has been a night out, strangely enough.
I can say having slept for 8 hours per night for the last six months and now since 2 weeks i'm back 3-5 hours per night that i definitely eat much more on days where i sleep 3-5 hours than on 8 hour sleep days.
I aim for 5-6 on weekdays, and 7-8 on weekends. Having to attend 8am classes during the week hurts me - I hope to improve that weekday number next semester.