Nicky Hilton addresses weight rumours

Paris's sister denies she has an eating disorder

Nicky Hilton debuted her latest fashion line Tuesday night – but chatter about her weight and her sister's love life took center stage.

Hilton, who has been dogged by Internet speculation about recent weight loss, hit back at the reports. "There's no truth to any starvation, eating disorders, rumors," she told PEOPLE on Tuesday at her Nicholai fashion show, part of the Mercedes-Benz Fashion Week at Smashbox Studios in L.A.

"I think the press has been printing a lot of pictures of me from unflattering angles," added the 24-year-old designer. "My friends see the pictures and they're like 'Oh my god are you okay?' And then they see me, and they're like 'Oh ... ' It's really not that interesting or true."

Hilton also addressed another major media fascination: Big sister Paris's new romance with Benji Madden. "They're super sweet," said Nicky. "He's a nice guy."

Madden and Paris caused a stir backstage when the high-profile couple arrived for the show, but Madden left his new squeeze so she could be with her sister until the show began. Paris, who wore a red and black halter dress from her sister's collection – and her new ring that reads "BM" – said the dress, is "one of my favorites."

Also at the show to support Nicky were parents Rick and Kathy Hilton – proud dad snapped photos of the catwalk on his iPhone – and boyfriend, David Katzenberg, who presented Nicky with a bouquet of white roses and a kiss on the cheek at the end of the show.

Paris Hilton and Benji Madden