Paul Ryan and Joe Biden won't have to weigh in ahead of their matchup tonight, but the vice presidential contenders are packing in pregame meals before their debate.

Before heading into the arena at Centre College in Danville, Ky., Republican Rep. Paul Ryan, known for his conscientious diet and exercise regime, planned to eat a light dinner of salmon and rice, according to aids. He had a tuna salad sandwich for lunch today, and spent the rest of his day studying up, relaxing with his family and working out.

Vice President Joe Biden also kept things light, planning a pre-debate meal of grilled chicken, with spaghetti and salad.

Biden doesn't always eat light. On Wednesday, Biden ate lasagna, made in part by his 6-year-old grandson Hunter. And earlier in the week he ordered sandwiches from Delaware deli Capriotti's.

During preparations, Biden's team snacked on M&Ms and animal crackers.

Tonight's debates pits Biden and Ryan against each other for their first and only debate. Given President Obama's lackluster performance in his first debate last week and the Republicans' determination to not lose their perceived momentum, both men are expected to bring their A-games and come out swinging.