I agree on making sure there's something that diabetic PNMs can enjoy - even if it's just water. During formal recruitment at the start of my junior year, I was talking to a PNM who offhandedly remarked that she was diabetic. We only had water and regular soda to offer (same as the other chapters), so she was drinking water. When I saw her name on the invite list for pref, I talked to the day chair and mentioned that we had a diabetic PNM. Diet Coke materialized. It must have worked - she joined AEPhi and became my little.
I made sure there was diet soda at bid day as well.
As for food and drink, it's been a looooong time since I was an active, and I don't remember what we did for food, but we offered non-alcoholic sparkling cider, water, and soda to drink. Most people went for the cider.