R&B singer Beyonce Knowles isn"t happy with the critics who triggered out issues relating to her gaining fat and ballooning after seeing her in a hip-enhancing Thierry Mugler gown in early March when she hit the streets of the Big Apple to film a promo video for her I Am... tour.

The weight issues have troubled the star previously also. She had piled on the pounds to portray Etta James in 2008 movie Cadillac Records and went on a strict diet to slim down for her role as Deena Jones in the big-screen adaptation of Broadway musical in 2006.

But the star's spokesperson insists Beyonce is fighting fit. Her representative tells Usmagazine.com, "This is not a weight-gain issue. Beyonce is in the best shape of her life. The exaggerated hips are a design element of a truly couture dress. Beyonce has always loved this dress."