If it's cheaper for that person to commute in order to eat then it's probably less wasteful from a financial perspective at least. Definitely possible to be even less wasteful of course, but I think without perfect weather and population models (which will never truly exist) it'll be hard to eliminate waste to a certain extent.

Something like this is usually not done out of economic incentives, but because of ethical and emotional incentives. In the end people do it to feel good, but might do more harm, just in another way.