A video clip of First Lady Michelle Obama grooving with a dressed-in-drag Jimmy Fallon on his late-night comedy talk show has gone viral on YouTube Saturday.

In the video, the pair, each clad in conservative slacks and cardigans, and Fallon with a long brown-haired wig, perform a routine dubbed "Evolution of Mom Dancing," to promote Obama's "Let's Move!" youth fitness and nutrition campaign.

The dance moves -- with names like "The 'Go Shopping, Get Groceries,'" and "The 'Out of Sync Electric Slide'" according to titles splashed on the bottom of the screen -- progress from a simple side-to-side step and ends with Fallon stalking off set as Obama rocks a smooth "Dougie."

The clip, which has already been viewed nearly a half million times since being posted Saturday and "liked" more than 10,000 times, has prompted effusive comments about the first lady and her first family.

"For the first time... we have a first lady with soul," wrote zestydude87.

And Rina Lubit wrote, "it may be just me but i really love the presidential family. they just really seem like sincerely good and chill people."

In an interview later on the show, Obama rates her husband's dance skills a "B," saying "he's got, like, three good moves."

Obama also touts her "Let's Move!" campaign, saying it has seen progress since she launched it three years ago, but there is still work to do.

"Over the past three years, we've seen a culture shift. Now people understand that this is an issue," she said.

"We've got better lunches in the schools, we've got companies putting grocery stores in under-served communities. We've got our athletes, our Olympians, working to get our kids more active. It's really heartening to see."

Obesity is a major health problem in the United States, where one in three adults and almost one in five children is overweight.

Among other initiatives for "Let's Move," the first lady, an attorney by training, has planted the White House's first garden since World War II and written a book with healthy recipes.