"I was really depressed because I was working so hard and I felt like my body was resisting me," she says. "And I got to a point where one night I got home from a workout and I remember staring at my food and thinking maybe I should just not eat."
"I realised I couldn't go out into the world - parading my body and myself in front of all these women who look up to me - and tell them that this is easy and simple and everyone can do this."
Heatherton, who has featured in campaigns for the likes of Valentino, Karl Lagerfeld, Versace and Dolce & Gabbana, says she fell into depression following her association with Victoria's Secret.
The model, who has shared candid posts on Instagram about her body image struggles, says she decided to tell her story in the hope that it will help other women.
"I'm willing to sacrifice my pride, in a sense, and my privacy because I know that if I don't speak about it, I could be withholding information that would really help women," she says. "It hurts too much to keep it in, and that's why I'm not keeping it in now."
She dated Leonardo DiCaprio from 2011 to 2012, and is now in a relationship with Australian musician Felix Boxsom.
-nzherald.co.nz