I just finished a NAGA tourney here in OKC and competed No Gi and Gi. My No GI match started around 3pm and my Gi started around 7pm after being there at 9am with my son who competed in kids division.
I ate candy bars, chicken salad (2), apples and oranges throughtout the day. In addition to carb drinks and mixed in Protein drinks with powdered BCAA's. I kept things light but filling enough to keep my strength and not heavy so I won't feel sluggish and full during the match. I also mixed in creatine and prework energy stimulus powder when it was time to hand in fight card so my energy was high enough during the matches.
At PL meets, I bring candy bars, gatorade and big tupper bowl of spaghetti and nibble throughout the day with energy drinks along with apples and oranges.
pedialyte, water, organic whole milk, eggs, avocados, bananas if you dont loath them like i do, all your regular supplements you take and the regular food you eat to perform at your best on training days. hydration is obviously more of an issue with weight cutting and repeated high demand activity on the day, lots of garlic and onions in a quinoa salad cultivated a pungent odor puts your opponents on notice.
im also trying to perfect the perfect length of facial hair to be short enough to be scratchy but long enough to be greasy and gross and hold the smell of powerful deli mustard