Working on the treadmill and eating lettuce is all the singer had to do for her first post-baby concert. Pop star Beyonce performed at Revel Resorts in Atlantic City, New Jersey, which was attended by Michelle Obama with daughters Sasha and Malia. Beyonce performed two dozen songs on Saturday night. Michelle Obama and the girls appeared excited throughout the concert, cheering Beyonce on — the daughters even sang along to the old school-sounding jam Love on Top. Beyonce opened the night with the upbeat End of Time, wearing a glimmering silver outfit and hot pink shoes that matched her nails. She followed that with more up-tempo hits like Crazy In Love, Get Me Bodied and Party. During the slower grooves, Beyonce brought on the emotion. She held back tears during a rousing rendition of Resentment and sat on top of a piano when belting the love song 1+1. The multi-platinum singer\'s Atlantic City concerts are her first since giving birth in January to daughter Blue Ivy. \"Y\'all don\'t know how hard I had to work,\" Beyonce told the crowd. \"I had to lose 60 pounds [27.22 kilograms]. They had me on the treadmill, eating lettuce.\" Beyonce paid tributes to late singers throughout the night, singing a verse of Whitney Houston\'s I Will Always Love You and giving Donna Summer a shout-out when performing Naughty Girl, which samples Summer\'s hit Love to Love You Baby. From: Gulfnews