Victoria Beckham has shared her pain over a lifelong eating disorder, calling herself "Porky Posh".

The fashion designer opened up in her new three-part Netflix docuseries, Victoria Beckham.

Victoria, 51, revealed she had battled an eating disorder since her teens, which was first triggered when she won a place at a prestigious theatre school.

"I didn't look like a lot of the other girls," she shared. "That's where I started getting a lot of criticism about my appearance, my weight."

She explained her family was oblivious to her struggle as she worked hard to conceal the disorder.

"When you have an eating disorder, you become very good at lying. And I was never honest about it with my parents," she shared.

"I never spoke about it publicly; it really affects you. When you're told constantly you're not good enough. And I suppose that's been with me my whole life."

After she was thrust into the public eye as a member of The Spice Girls, Victoria found it hard to cope with relentless commentary about her appearance.

"I really started to doubt myself and not like myself, and because I let it affect me, I didn't know what I saw when I looked in the mirror," she shared. "Was I fat? Was I thin? I don't know, you lose all sense of reality. I was just very critical of myself. I didn't like what I saw. I have been everything from porky posh to skinny posh, I mean, it's been a lot and that's hard."