“Let’s Moooooove!” Michelle Obama yelled, standing on stage with Iowa celebrities, Olympic athletes and college students to lead 14,000 kids in dancing to celebrate the second anniversary of her healthy eating and fitness initiative.

Dressed in a red and white sweater with a heart on it, the first lady smiled broadly as she jumped and clapped, making the Ninja moves and fist pumps of the Northern Iowa University dance “The Interlude.”

After the dance, a breathless Bob Harper — one of the trainers on the Biggest Loser TV show — presented Obama with a massive cake to celebrate the program’s second birthday.

In keeping with the healthy eating mantra of the “Let’s Move” program, the multi-story cake was made of layers of bananas, apples, grapes, oranges, pineapples and grapefruit.

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Photo credits: Michelle Obama at an event to promote her “Let’s Move” initiative at the Wells Fargo Arena in Des Moines, February 9, 2012. REUTERS/Kevin Lamarque