How much food have you thrown out lately? It could be a lot, a little or none if you don't throw away the left overs. An easy way to avoid having food left over is to estimate how much would be enough for one meal and cooking only the amount of food that will be eaten completely or if any is left over the quantity would be too little to concern you. Do this for a long time and you'll be saving a lot of money.
I really make sure that I only cook just the right amount because I hate throwing food. I also don't throw away food when it's not fully consumed. I keep it in the freezer and just microwave it the next day. They said keeping it in the freezer will help preserve the food for a long time. So far, I haven't had any problem with this and I can really consume the food even days after. But of course, I still use a bit of judgment and smell the food before I consume it.
I threw out almost an entire pound of brisket, since I didn't like how it came out, and the sauce I cooked it in was way too overpowering. I had never cooked a brisket before, and figured I would slow cook it. I came across a simple recipe that said to mix BBQ sauce with some soy sauce and water then simply pour it over it and slow cook it for several hours. I figured the fat cap would melt off during the slow cooking process, but it didn't, leaving a gross gelatinous mess for me to peel off the roast. Then I over cooked it, to the point where I couldn't really slice it, it all fell apart. To make things worse, the sauce mixture I put in there must have caramelized somewhat, because it took on a very burnt gross taste that I didn't like at all.
Well when that kind of thing happens especially when trying out new recipes you just might not have an option but throw out the entire meal. It's why I never try new recipes after one of them turned went awry. I tried to make custard but the taste was awful that I didn't think it necessary to give my taste buds a second chance to find out if they got it right the first time. Maybe one way to save food is to avoid cooking stuff we've never cooked before or in ways we've never tried?
We throw hardly any food away because my dad will cook it up and eat it, or we will give it to my dog who will happily eat "people food". When I was a kid, the day before we got paid would be special stew night which would involved using pretty much everything in the cupboard that we had not used.