I'm not sure if most individuals even have a choice in the matter. Some can make small changes and some do... Like the employees of grocery stores and other food vendors who rather than throwing out food as they're told, give it to shelters and homeless. There are quite a few places that are only able to feed the poor because of certain local vendors given them food that otherwise would be thrown out.

But to actually solve the issue, we'd have to do this at a much larger scale.

Lets say a government decided to collect all such food and use it to feed the poor. It probably wouldn't solve the issue completely, but they would at least not be hungry.

The issue of homelessness is actually quite similar. There are tons of empty houses and apartments all over the place. Maybe not in every area though. They could simply choose to put the homeless in such places and even employ others to clean and fix them up.

But to do such things, you need some kind of large group of people to do it. Individuals already do similar things but there just aren't enough. There are far more people that just don't give a shit or feel like they aren't responsible or some such than there are people that take responsibility and do little things to help.

We really need government think tanks working to solve these issues.

Sadly, many think that these issues shouldn't even be addressed by governments, as many are very inefficient and wasteful. But we've tried to deal with these issues with small non-profits and it just doesn't work. They simply aren't large enough and they have no teeth.