Appearing comfortable and good humored, Obama bantered playfully out of earshot during a commercial break with Leno and one of Leno's producers, Michele Tasoff.
He announced he had "definitively" quit smoking. He confessed there were certain things that he would like to take in moderation: Republican presidential candidates, reality television, and healthy food during Halloween.
Pressed to reveal what he thought of the Republican presidential debates, Obama cracked:
"I'm going to wait until everyone is voted off the island."
When Leno pressed Obama on his insistence that his daughters not watch reality television's "Keeping Up With the Kardashians," Obama acknowledged a bias against reality television.
"There's this program on C-SPAN called Congress," he said.
Asked about first lady Michelle Obama's anti-obesity and healthy eating campaign, the president said he warned his wife that if she insisted on giving fruit and raisins as treats on Halloween, trouble might follow.
"I told her the White House is going to get egged if this keeps up," he said, suggesting that she might want to add "a couple of Reese's Pieces or something."