Once a week. My boyfriend is not a stocker. If something sits in the cabinet too long he claims it's "too old". We pretty much get the same things EVERY week. If the meat is on sale (buy one get one free) we will of course get the free one. We do not have a lot of freezer space. Plus I have to get a bag of carrots for the dogs each week.
I work right across the street from Costco so my co-worker and I sometimes make a trip at lunch to get a few items....and a cheap hot dog for lunch.