Why women need some fat to stay healthy

Instead, she has thrived. Her internal organs, brain, and bones developed normally, though her body is tiny. Since she has no fatty tissue in which to store nutrients, she has to eat every 15 to 20 minutes to have enough energy to get through the day. One brown eye started clouding over when she was 4 years old, and now she's blind in that eye and has only limited sight in the other.

"Some days life doesn't make sense," she writes in "Be Beautiful, Be You." "You just have to change what you can, ask for help and pray about the rest."

She notes her triumphs and posts inspirational messages on Tumblr, and says that she's learned to embrace the things that make her unique. Instead of trying to retaliate against people who have made her feel badly, she sets goals for herself and pushes herself to succeed in spite of the haters. She's even reclaimed YouTube, video blogging about everything from bullying to hair-styling tips to staying positive.

"I feel really glad that I don't look like the celebrities out there that are so beautiful," she told Dr. Drew. "There's a lot of stereotypes attached to that." Not looking like a supermodel "gives people the opportunity to know you personally," she explains. "If they're willing to take that extra step they'll get to know the person you really are."

Of course, the horrible comments left on that old YouTube video stung (the video has since been removed, but Velasquez says she read every single comment). Now, she says, she understands that they're "just words."

"I'm human, and of course these things are going to hurt," she said. "Their judgements of me isn't who I am, and I'm not going to let these things define me."

"I didn't sink down to their level," she said in a follow-up video on YouTube last year. "Instead, I got my revenge through my accomplishments and determination. In the battle between the 'World's Ugliest Woman' video vs. me, I think I won."