I've never done competitive eating but once at a Lobsterfest, not racing against any clock, I put away over a DOZEN large lobsters (tails, claws and legs) AFTER filling up at the raw bar (mussels, clams, cooked shrimp, oysters). The next day I'd lost a pound. The secret? Lemon juice and cocktail sauce instead of butter.
I'd do it again, too.