I don't eat out much. Nor do I eat in much these days either. Little time, so usually eat one meal a day or snack on fruit and veggies with enough cheese for some protein in the morning and late at night. If I do eat out, I generally take home enough to feed me for another day or so.

My Mother, sister and I, all single women living alone 300+ miles from one another often lament at how much food, especially fresh produce, that we end up tossing out because we could not eat it all before it started to rot. Financially, it is cheaper to buy the smallest quantity available in the produce section and toss or compost what goes rotten after a week or two before we can consume it all than to to hit a salad bar every evening. And while I do enjoy cooking, I am one of those who rarely will cook for myself alone. So I go through periods of surviving on microwaved meals such as 'Lean Cuisine,' or late night snacks of crackers, cheese and carrot sticks, and slices of avocado. (carrots keep a long time.)

For single people and even for just 2 person adult households with very busy schedules, it is hard to affordably buy fresh produce and veggies in small enough quantities to not end up wasting a huge amount of food. At least that is the case in my neck of the woods. May be different in other places.