<p>President Barack Obama has spent Monday night at a nearly 5-hour dinner at the home of Sam Kass, a senior policy adviser for nutrition policy at the White House.</p>
<p>The dinner, about a mile away from the White House in the Logan Circle neighborhood, also included Anita Decker Breckenridge, Obama's deputy chief of staff. The president had returned to Washington just after midnight Monday in a break from his summer vacation on Martha's Vineyard.</p>