I'd stop handing out treats at these events.
I used to work for a retailer, in the call center for their store credit card. At the beginning of each month we would order treats to kick off our new goals. Cookies, donuts, etc. We had people taking not just an extra cookie - but an entire dozen or so. To take home to their kids. Our director came out once to greet people and saw it....no more cookies!
We also did holiday giving trees - we had one with a pet theme, so you could donate toys/treats, etc and another one with a hat/glove theme. You'd bring items in and put them on the tree, and they'd be donated to a charity. One day I was walking by and there were two women perusing the hat/glove tree - the first woman was telling the second "you aren't supposed to take things from it" and the second woman saying "why not, my kids need hats and gloves, too".