All it takes is a little proactive thinking to prevent this sort of needless waste. By freezing leftovers and spending just a couple of minutes each day reviewing what's in your refrigerator, you can save yourself time and money, so why not do it? Is the soup you prepared for lunch on Sunday still sitting uneaten on Tuesday? Pop it in a freezer-safe container (with a little room at the top for expansion) and into the freezer it goes. If you wait until Friday or Saturday to come to the same conclusion, you're already too late - the soup won't be fresh when you thaw it out. I suggest freezing most foods within 3 days of preparing them to ensure quality and freshness once thawed. Freeze items like cooked lentils, rice, or beans in 2-serving portions so that they're easy to thaw quickly and add to soups, casseroles, or salads when you need them.
Beyond freezing, the other way that I like to prevent food waste is by getting creative with what's on hand. Extra shredded Brussels sprouts from a salad this week? Try throwing those into a soup, or simply sauté them with a bit of olive oil and garlic and toss with freshly boiled pasta. Leftover herbs? Blend in a food processor with a bit of oil and vinegar, and use as a dressing all week. Or, freeze small portions in an ice cube tray or small plastic baggies. Thaw and use to add some fresh flavor to pastas, soups, and meats at a later date.
Also, know that many grocery stores will be flexible and sell you just what you need, if you know to ask. Don't need that whole head of cabbage? Ask if they'll slice it in half and sell you a smaller portion. Don't need that 8oz block of Romano cheese? Ask them to slice you a 4oz portion instead. It usually works and never hurts to ask!
Juicing is a great way to use up odds and ends from produce that would otherwise go to waste. I run cucumber peels, broccoli stems, and other such scraps through my juicer and these scraps turn into nutrition gold!
Lastly, please consider composting! The EPA states that “Organic (plant-matter) waste in landfills generates, methane, a potent greenhouse gas. By composting wasted food and other organics, methane emissions are significantly reduced.” Pretty much all produce is fair game, but here are a few things that you should not compost: cooking oils, meat and dairy products, and grains. (The reason for this is that they will attract pests.) It’s super easy to set up a compost system in your backyard, and you can save money by “making” your own nutrient-dense soil supplement for your vegetable garden. (Simply search online for tips and tricks for the best compost set-up for your yard.) Find more information on composting here.