I am only just beginning to realise I buy too much food, I don't waste what I use, usually make curries or pies of leftover meat the next day. It's the sell-by dates that are my failing, I will not eat anything out of date, or for example if I buy a jar of mayonnaise, I find that once opened to use within 4 weeks or so. My biggest waste is yoghurts of which I may only eat one and the rest is thrown away. I cleared my freezer recently to find that although I could freeze a pie or something I had to use it within one month.