Well, my son's trip went well. I didn't hear from the chaperone until the night before he left, so I'm glad I planned ahead.
Since it was such a quick trip, they were limited to just a carry-on bag, so I had to make sure the foods I packed wouldn't be confiscated by security. I wound up packing him a little container of salad dressing, a bar, muffin, couple of cookies, fruit, 2 slices of bread and a packet of peanut butter, crackers and beef jerky. We drove J. up to the airport, so he ate lunch on the way. Dinner, once he got there, was to be roast chicken, baked potato and salad, which should have been fine, but I reminded J. to ask about how the chicken was prepared. Which was a good thing, since it had been cooked with soy sauce! So, he skipped the chicken and had a huge, plain baked potato and salad. Breakfast went fine - the muffin I'd packed, eggs and bacon. Lunch, he brought a sandwich with him and was able to grab cantaloupe and something else from the cafeteria. This trip, I made sure he had some money along, in case it was needed (learned my lesson after the last trip). He bought a snack at the airport, but that was it. Fortunately, he didn't need it again as he lost his wallet. (Thankfully, the airline found and returned it later in the week.)
Oh, and my son did well at the competition - their team came in 3rd place and he came in 14th as an individual. He won't be making it to nationals this year, but that's okay (I don't think I'm ready for him to take a trip across the country just yet).