If you want to lessen the amount of food you toss try smaller portions or order less when eating out. It is safe to use left overs for up to three days if you have some from your meal. Why not make them part of lunch the next day. If you have a dog you can use some of the veggies and meat to make homemade dog food with. (No onions, garlic, grapes.) We use carrots, green beans and peas if we have them.
I think having to toss food once in a while happens to all of us, but a chronic habit of it indicates a little bit of a problem to me. In order to be good stewards of the this earth we do need to do our best not to toss good food away. My sister and I will often make at least one meal a week that is out of left overs, like beans, potatoes and the chicken or hamburger from the day prior. We seldom have food to toss.
If we have veggies that have spoiled in the crisper, or that are left over after three days we simply add them to our compost pile. In this way the squirrels, birds and sometimes skunks can eat them or they can be added to our flower and veggie garden instead of fertilizer. It is better than just throwing it away.