Food is available on and off the campgrounds, however, tight budgets don’t always allow for daily dine-outs. Plus, festival-goers get searched every time they re-enter the festival grounds; no re-entries, no cutsies, everybody waits, every time.
Canned, preserved foods are always recommended: fresh fruit, Slim Jims, any foods you don’t mind eating cold. Bonnaroo doesn’t typically allow outside food in, but you can at least eat your food outside and then head back in. Make sure to check out guidelines on food and drink as they tend to change on an annual basis.