At 30, Amanda Beard has come further than Olympic contenders half her age. The medalist has competed in four summer games and attributes her success to a strict exercise and diet regimen.

"We burn a lot of calories," she said, "but I don't eat that much. I mean, I don't think I eat that much more than most normal people... I kind of just constantly snack throughout the day."

Another swimmer at the U.S. Olympic Trials, John Higgins from the University of Missouri added, "It's just about making sure you eat the right foods at the right times."

He balked at mention of high calorie diets, like the 12,000 a day Michael Phelps reportedly consumed while training for the 2008 Olympics. "You don’t want to over eat because then it will draw blood away from your body."

Higgins said, "I mean it’s just important to make sure you get those complex carbs so you make sure you have fuel throughout the day to compete and making sure you continuously have something so you’re not hungry."

Just after crushing her lifetime best of 1:08:08 in the breaststroke Tuesday morning, achieving a time of 1:06:52 in the preliminaries, Breeja Larson said she makes sure to keep her body fueled with simple and easy-to-find foods.

"Every day, I probably have three or four peanut butter and jelly sandwiches, and always have some kind of meat for dinner, and for breakfast. I always try to have a lot of oatmeal (at breakfast)," she said. Keeping the same foods in her body wherever she goes to compete, she said, keeps her on track. Larson, a swimmer from Texas A & M, later won the event easily to seal her Olympic team fate.

Ellen Lobbs, a swimmer with the University of Texas said, "Nutrition is always important, but it becomes even more important in the couple weeks leading up to an event like this because we're training a little less. So we're not actually burning as many calories as we did in the main training season."

To keep her protein high, but her calories low, she substitutes almond butter for peanut butter. It's a trick her coach taught her. "And it's really good," Lobbs said.

For Creighton Prep graduate, 18-year-old Will Raynor, good carbohydrates are key. "Fruits, vegetables, pastas, grains." Raynor said he stays away from processed or fast-food “junk” when he's training.

His dreams this Olympics would go no further than preliminaries. Raynor didn't fare as well as he'd hoped in the 200 meter backstroke preliminary.

His competition over, for now, Raynor planned on indulging in the kind of food he doesn't usually touch Tuesday night. "Some greasy burgers, bacon, yeah." Then, it will be back to the grind, heading to college in Michigan, and training for the 2016 summer Olympics.

The Century Link Center's Levy Restaurants has cooked up some 65,000 meals so far for athletes and others at the Swim Trials. "Just for this first session, we've ordered, roughly around 4,000 pounds of chicken, 2,000 pounds of beef, and 3,000 pounds of produce," said Executive Chef Lamar Nolen. "And that's daily."

He said most of what the athletes are eating is healthy, "a lot of whole grain bread, oatmeal, fruits." But make no mistake, they have decadent options as well.

"We had a young lady here who when she saw our dessert display she was almost in tears because she couldn’t believe the choices," he chuckled.

"In 2008, we made the mistake of putting the dessert table at the front of the door, so all the athletes gravitated toward the desert and forgot about the rest of food. So this time we put it on the end so they can go through all the other lines before they get to the dessert."

But "dessert" is not part of Beard's vocabulary. "I mean, you have to make choices - chocolate chip cookie or swimming fast. You have to think about those things."