From the TV cartoon South Park - Cheese Poofs is the favored snack of Cartman, regarly bought for him by Cartman's mom. The ultimate non-nutritous TV snack.
After the tv series got regognition, "cheese poof" became a popular slang word with various meanings. It can be used as an insult as well as a word for all sorts of unhealthy snacks.
According to rumour, "cheese poof" crisps exist in the real world too. Possibly an attempt to ride on the South Park wave.
2. (extended) Man, I'm hungover. Let's go grab some cheese poof kinda snack.
3. (insult) You wanna go home to bed and it's not even midnight? Don't be such a cheese poof!