I've been green juicing, so I go every other day to Trader Joe's or one of the other whole foods stores in the area to replenish my stock of greens. It takes A LOT of greens to make a glass of juice.

As needed. I try to get meals for a week but it doesn't always work out and some things just have to be fresh that day (corn, fish, etc.). Normally I'd say twice a week is average.