Jesy Nelson hated herself for being ''the fat one from Little Mix.''

The 28-year-old pop star - who shot into the limelight in 2011 when the band became the first group to win 'The X Factor UK' - has had a tumultuous relationship with her body over the past eight years and has gone on an epic journey to lose weight and sex up her appearance in order to fit in with the rest of her band mates.

Taking to her Instagram account, the brunette beauty uploaded a photograph of herself in 2011 sitting on a sofa during an interview on 'This Morning' and wrote: ''6 months ago this girl was someone I just wanted to forget. I wanted to erase her from my mind and everyone else's memory. I didn't see her as Jesy I saw her as ''the fat one from Little Mix''. Up until now I hated her not because she'd ever done anything bad but because I was made to hate her by endless amounts of trolling.''

The 'Shout Out to My Ex' hitmaker has been filming a documentary for the BBC based on her mental health and her battles with trolls, and she believes it wasn't until she started to delve into her past that she learned to love herself more.

She explained: ''Since filming my documentary for @bbcone and @bbcthree I've learned so much more than I ever expected to. Thanks to all the inspirational people I've met on this emotional journey, I now love the girl in this photo. I've made this documentary for 2011 Jesy and for anyone who might be feeling like she did. I refused to speak about how I was feeling for so long. I was embarrassed and scared to. But I was so wrong to feel that way.

''Please if you are feeling how I did, SPEAK ABOUT IT. Talk to your family, speak to your friends, there's always help out there.

''If you'd have told that girl one day you won't feel sad anymore, I'd never have believed you....and here I am. Now when I look in the mirror, I don't see Jesy the fat one, I see Jesy the happy one! (sic)''

Jesy's boyfriend Chris Hughes jumped to praise the singer for her courage.

He wrote: ''That's my favourite Jesy, she's a princess.''

It's not yet known what Jesy's BBC documentary is titled or when it'll air.