You could always go another route and have parents provide the food. I know I'm in the minority on this forum for it, but I don't provide any food at all.

But it is an interesting thought, with all the stuff I had to do to get my license nothing specifically about food poisoning came up - other than making sure counters and table tops are sanitized to prevent food borne illness in that regard. I but I would think it is part of the liability insurance coverage.