Beyonce Knowles stunned spectators when she showed her post-pregnancy figure at a four-date concert in Atlantic City. The series - Beyonce's first since her daughter Blue Ivy's birth - saw her costumed in a custom-made Ralph and Russo creations.

"Y'all have no idea how hard I worked! I had to lose 60 pounds. They had me on that treadmill. I ate lettuce!" Beyonce told US Weekly. A satisfied singer then said that she would treat herself to a chocolate.

"Now tonight I'm gonna get chocolate wasted!" Beyonce exclaimed.

"She looked better than ever in each of her four astonishing looks plus two amazing headpieces, crafted with over 500,000 Swarovski elements. She completed the look with contrasting hot-pink Stuart Weitzman Mary Janes," the Grazia Daily reported.

"Beyonce is a true representation of the Ralph & Russo woman who is strong, powerful and independent. She is an inspirational performer and creative genius and collaborating with her is always such a fantastic experience. We had so much fun designing these outfits made with Swarovski Elements, all of which were created to provide her with a truly unforgettable stage presence," designers Tamara Ralph and Michael Russo of Ralph & Russo said.

The singer's first post-pregnancy concert was a true success and attended by special guests Michelle Obama and daughters Malia, 13 and Sasha, 10.

"They sat up in a private balcony with Gayle King. Michelle was jamming out to "Crazy in Love". 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? Together, all three of them did the 'Single Ladies' dance moves," a source told US Weekly.

"We do cardio and plyometric moves like lunges and jumps on and off a bench. The 5-foot, 9-inch beauty has been breastfeeding Blue Ivy and is sticking to a strict diet of vegetables and grilled meats. She avoids processed foods, "You don't have to eat only celery sticks. Be sensible and exercise constantly," Marco Borges, Beyonce's trainer, advised.

"Beyoncé and Marco are up at 5 a.m. for a two-hour workout, and they do it again at 5 p.m..They do a mix of cardio, Pilates, plyometrics, yoga and, of course, dance. Beyonce has also complemented her strict workout regimen with a diet of "protein shakes, egg-white omelets, pineapple chunks, and lots of ice-cold water," a source earlier told Star Magazine.