Obama, who has proven in the past that she has a great sense of humor, participated in a segment called "Ew!" with Fallon and comedian Will Ferrell, who dressed up as teenage girls. During the parody, she declared that jelly donuts and potato chips are "ew," and suggested the "girls" try kale chips instead.
The first lady also promoted a new social media campaign to get people moving by showing what they've got on social media, using the hashtag #LetsMove.
"What we're asking people to do is show us how you're moving. We want people to Facebook it, tweet it, Instagram it," she said.
And if enough people respond to her call, Obama teased, "we'll have a little surprise. The president, and maybe the vice president, will show us how they move."
She also took advantage of an opportunity to push the Affordable Care Act and encouraged young adults to enroll in a plan.
"Young people are knuckleheads. You know? They're the ones who are cooking for the first time and slice their finger open. They're dancing on the bar stool. But while young people think they're invincible, they're not. You know, life happens," she said, adding that thanks to the law they can get insurance for "less than the cost of gym shoes."
The first couple's daughters, Malia, 15, and Sasha, 12, won't be dancing on bar stools any time soon, but like most kids their ages, they are pulling away from their parents in search of a more typical teen and tween life, which does not include a SWAT team at school events.
"They really want normalcy and the White House isn't normal. So they'll go other places," Obama said. "And so I'll say, 'Don't you want to invite your friends over to watch a movie?' She's like, "no one wants to come here.'"
Part of being normal is the ability to function in the real world, which includes driving. The first lady issued a warning to the citizens of Washington, D.C.: Malia is turning 16 this summer and will be getting behind the wheel – though not in the presidential limo.
"Malia Obama on the road. Frightening," she quipped. "I have security, so I'm good."
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(Photo: Lloyd Bishop/NBC/NBCU Photo Bank)