If you're anything like me, and if your parents were anything like mine, then you probably have a major fear of wasting food.
In theory, eating everything on your plate sounds like good economics but it's not good if you're calorie counting. The thing is, eating the last bites of your kid's chopped up hot dog is not doing anyone any favors, except maybe the person who collects dues at your gym. Consider this: 1/4 of a hot dog is 45 calories and 1/4 of an easy mac package is 57 calories, both of which you are just meaninglessly eating. So steer clear and if it's just too tempting, then give your kids less on their plate and when they ask, give them more.
If you are noticing that you yourself constantly have leftover food on your plate when eating out, then try ordering kids meals or bringing what you can't eat home for leftovers.
Also, if you buy something and don't like it, then don't eat it just because you feel like you should. Afraid of wasting? Start composting, it's a great way to throw out food without feeling terrible about it. Still worried about the kids starving in Africa? Then instead of stuffing your face on their behalf, donate money to charitable organizations like ONE, the campaign to make poverty history.