It's all in the title really! We're about to really tighten our belts, but DH and I both tend to graze the cupboards. I know what the planned meals are and what ingredients we need, but DH had a cheese and cracker binge last night and we barely have enough cheese left for our cauliflower cheese tomorrow. Right now it doesn't matter, but when I don't have enough food budget to buy more I'm going to get grumpy. So I think it's best to work out a strategy when everyone is calm.
(I dread to think what happens when you have teenagers - I can remember my brother (who was a teenage athlete at a national level) eating a whole box of cereal as a casual snack between dinner and his "something to round off the day" at bedtime!)