The 23-year-old former Disney star, who was on "The Ellen DeGeneres Show", said the reaction she got online was weird, but she was not bothered about it, reported E! online.
"It was the first time I'd ever been called fat. But it was weird because it's not just oh she's fat. It's like she's a mess.
"She's gone off the deep end. I'm like because I'm on a vacation wearing a bathing suit? Actually technically that is a little too small for me, but I didn't care," Gomez said.
"I don't what them to win. It's so annoying when I see it all over the place and everybody thinks they can bring me down. So, my immediate response was I'm gonna post a picture and I'm like 'I'm happy with me ya'll' and that was going to be the story the next day. I wasn't going to let that be the story," she said.