Lawrence's comments came Thursday during a Yahoo chat interview, the Los Angeles Times reported.
"No, this isn't how Katniss is going to look in the next movies, don't worry," the 23-year-old "Hunger Games" star said. "I'm wearing a wig [in them].
"I cut it earlier, and it was just kind of like [shoulder-length] and it grew to that awkward, gross length," she said. "I just kept putting it back in a bun, and I said, 'Well I don't want to do this,' so I just cut it off."
Lawrence offered some advice for those dealing with bullies.
"Screw those people," Lawrence said. "It's something that everybody experiences. I experienced it in school. The world has a certain idea -- we see this airbrushed perfect model image. ... You just have to look past it. You look how you look. And be comfortable. What are you gonna do, be hungry every single day to make other people happy? That's just dumb."