Michelle Obama managed to spin a hula hoop for 142 revolutions at a fair at the White House to promote children's health.

America's First Lady, a champion of healthy eating who is often celebrated for her muscular arms and athletic physique, hosted a group of school children to the White House for a Healthy Kids Fair on Wednesday.

"One of our goals was to focus on the importance of educating our kids about healthy eating," said Mrs Obama. "So it wasn't just about planting a garden," she said, a reference to the family's vegetable patch on the White House lawn.

Noting that one in three American children is overweight or obese, Mrs Obama called on parents to improve their children's diets. She urged children to reject junk foods and desserts in favour of healthy foods - but she also encouraged exercise.

Setting an example for her audience, the First Lady managed to keep her hula hoop aloft for 142 revolutions before it crashed to the ground.

Mrs Obama's hula talent has been noted before by her husband. In July, 2008, Barack Obama told People magazine that his wife was "the best hula-hooper I know. Once she gets the rhythm going, she can drop to her knees!"

(Agencies)