Even one of the world's top fitness trainers needs to indulge once in a while -- with limitations, of course.

While dining with a pal recently at Stanton Social, Jillian Michaels from "The Biggest Loser" got a kinda-sorta sweet surprise when the Lower East Side restaurant unexpectedly sent dessert to her table.

"When dessert was brought over she yelled, 'OMG! What are you doing to me?' " a restaurant-goer told us. "She then was insistent that the server help eat the treats."