surely the issue isn't paying and not using, but unnecessary waste/spend. So a gym membership is unnecessary as you can run outside, use body weight, buy a set of weights and have them at home etc?
i go to mcd and order a wrap of the day for £1.99. they give me a big brown bag, napkins, a paper straw if i have a drink, all of which i don't want and go instantly in the bin. think of all the money wasted that could go to starving kids.
my point being, that as much as i get the concern, there's plenty of "waste" in the world, that happens naturally and can't be stopped. if you try to live a world with no wasted food, you end up creating a situation where people don't want to eat out. it's also better to waste food, then over eat food and then be overweight, need to spend to now go gym etc.