Some hit the mark on calories, but were sadly uninspiring on the plate — fish with no verve, chili devoid of any seasoning.

“You don’t need salt!” insisted Mr. Kass. Well, yes you do.

“Last year it was all about quinoa and strawberries,” said Ms. Steel. “This year, lots of salmon and Greek yogurt. It seems like every plate has a message.”

On Thursday Mrs. Obama will announce the winners, who will attend a lunch at the White House on July 9, during which they will chow down on healthy food — including a selection of the winning recipes — and visit the White House kitchen garden.

“Our Kids’ State Dinner is one of my favorite events of the year,” Mrs. Obama said in a statement. “And the kid chefs who come from around the country never cease to impress and inspire me with their creativity and ingenuity.”

The simple act of creating the meals for the judges was something to behold. Each recipe, scaled to a serving, was prepared in the Washington Convention Center by cooks from D.C. Central Kitchen, a community kitchen that trains unemployed adults to cook. “It’s a herculean task,” Ms. Steel said, noting the sprawl of tables covered with “bodacious banana muffins,” “nummy no-noodle lasagna” and the like. Judges moved along the tables like so many guests on a cruise ship, tasting and then discarding their forks into a basket for washing.

It was feel-good situation, but since it was also Washington, some controversy arose.

The miniature pizza with vegetables and cauliflower crust, submitted by Olivia Neely, a 10-year-old from Kansas, was deemed delicious by all. Mr. Kass and Mr. Post were nonetheless unconvinced, insisting that there had to be some type of flour in the recipe, so stable, so delicious was this crust, which was billed as gluten-free.

“Has to be,” insisted Mr. Kass, in a shocking accusation of fraud and deceit. Mr. Post agreed. A trip to the kitchen ensued. The cooks assured all that there was in fact no flour in the recipe and that the cauliflower purée stood on its own accord. Mr. Kass seemed somewhat sheepish, although perhaps not enough. The pizza is among the finalists.

The full list of winners and recipes will be available online at recipechallenge.epicurious.com.