Michelle Obama does sketch comedy with Jimmy Fallon: 'Ew!'

How do you get Americans to pay attention to a healthy-living initiative for kids four years after it’s launched?

Take it to New York City, and join Jimmy Fallon and Will Ferrell – both in drag as teenage girls – on a basement couch, a la “Wayne’s World,” and pull out the kale chips. That’s what first lady Michelle Obama did Thursday night on NBC’s “Tonight Show,” demonstrating her comedy chops in a sketch called “Ew!”

Mrs. Obama played herself, and that meant promoting fitness, saying “ew” to jelly doughnuts, and getting up off the couch for an “ ‘Ew’ dance party.” It wasn’t “The Evolution of Mom Dancing” – perhaps the most eye-popping TV performance ever by a first lady – but Mrs. Obama showed, once again, that she can move.

And that was the point. Her Let’s Move! campaign, four years old this month, is Mrs. Obama’s main initiative as first lady, and Fallon has become a regular stop on her circuit. Two years ago, she competed with the comedian in feats of strength at the White House – push-ups, dodgeball, a potato sack race – for the second anniversary of “Let’s Move!," back when he was host of “Late Night with Jimmy Fallon.” Last February, it was mom dancing.

This year, the fourth anniversary coincided with Fallon’s debut as host of “The Tonight Show,” a week packed with A-list guests. After the “Ew!” sketch, she joined Fallon on the regular interview couch for some conversation about her girls, who we’re guessing may have taught her a bit about things that are “ew.”

Now 15 and 12, Malia and Sasha Obama aren’t as into hanging out with their parents as they used to be.

“They want nothing to do with us,” the first lady said. “I am so serious.”

Mrs. Obama also warned the people of Washington, D.C., that Malia is getting close to one of the dreaded (to parents) milestones of adolescence: learning to drive.

After the Obamas leave Washington in a few years, the girls “have got to be able to function as normal people, and driving is a part of that,” she said. “Ladies and gentlemen of D.C., watch out!”

Mrs. Obama also made a push for enrollment in health insurance, and came up with a new term for “young invincibles,” the 20-somethings who don’t think they need coverage: “knuckleheads.”

“They’re the ones cooking for the first time and slicing their fingers,” she said. And “dancing on the barstools.”

While in New York, Mrs. Obama promoted another of her healthy-living initiatives, the Drink Up campaign, which encourages drinking water. She visited the New Museum in Manhattan, which has an exhibit of street art that encourages people to drink more water. She also appeared at a private fundraiser, reportedly at the home of Obama “bundler” Maneesh Goyal.