It's possible to have 0 dollars after paying other bills before your next grocery shopping trip so no matter how cost effective these things are they won't help. Once you're behind on rent or mortgage and gas bills and electricity bills and loan payments and credit card debt is racking up 20% interest and you're using every cent you have to stop those creditors from coming after you your only option is to cut down on other costs, even if they are relatively important, like food.