Beyonce Beyonce

Hold the salad — Beyoncé wants some chocolate!

In her first concert since giving birth to daughter Blue Ivy in January, the superstar singer showed off her svelte post-baby bod Saturday night — a result of a strict diet and workout regimen.

Check out our dramatic celebrity weight loss gallery

"Y'all have no idea how hard I worked!" Beyoncé said on stage during her concert in Atlantic City, according to The Associated Press. "I had to lose 60 pounds. They had me on that treadmill. I ate lettuce!"

She added: "Tonight I'm gonna get chocolate wasted!"

Beyonce named People's Most Beautiful Woman

Among those in the star-studded crowd were Gayle King, First Lady Michelle Obama and her two daughters, Sasha and Malia. "Michelle was jamming out to 'Crazy in Love,'" a concertgoer said. "When Beyoncé told the crowd to get up and jump, [Malia and Sasha] stood and started dancing and jumping. They were shouting when Beyoncé asked, 'Do girls run the world?'"