Gabby Douglas performing at the London Olympics 2012
Gabby Douglas performs at the London 2012 Olympic Games. Reuters

Michelle Obama teased U.S. Olympic gold medalist, Gabby Douglas during her appearance on the "Tonight" show with Jay Leno, for eating fast food from McDonald's.

First Lady Michelle Obama has been a health advocate during her time in the White House with her husband, President Barack Obama. Two years ago, she started the "Let's Move Campaign," an "ambitious national goal of solving the challenge of childhood obesity within a generation so that children born today will reach adulthood at a healthy weight and unveiled a nationwide campaign," according to a White House press release. Superstar Beyonce even teamed up with Michelle Obama last year to promote the campaign's mission to fight childhood obesity.

While sitting next to the first lady, Douglas admitted to Leno that she celebrated her success by "splurging on a McDonald's Egg McMuffin."

Michelle Obama teased the gymnast about her food choices, saying "'Yea, Gabby, don't encourage that! But I'm sure it was on a whole wheat muffin."

"'You're setting me back, Gabby," the First Lady continued, which caused Douglas to smile and say "Sorry!"

During the 2012 London Olympics, which ended on Sunday, 16-year-old Douglas became the third straight U.S. athlete and first African-American to win the all-around title and won two gold medals. She will likely earn $5 million to $10 million in sponsorship deals over the next four to five years, Robert Tuchman, a sports and entertainment marketing expert, told Forbes.

Leno later asked Douglas whether, after training her whole life for the Olympic games, the dream of winning matched or differed from the reality.

"I think it's very different, and when I mean 'different' it's in a better way," Douglas replied. "I mean, I never thought I would be doing the show with the first lady, or even you, Jay."

On Tuesday, following her appearance on the "Tonight" show, Douglas caused a stir as she arrived in New York. As soon as she stepped off the plane at John F. Kennedy International airport, she was swarmed by fans and paparazzi, according to TMZ. She needed help from the NYPD to make it to her SUV.