'Explain this to me. The site seems to be lots of women in their underwear. How is that going to start a revolution in society's thinking?'

It was the day after I'd accepted a role as an ambassador for The Body Confidence Revolution. I was immediately on the defensive, but actually, it was a fair question. I'm sure it won't be the only time it gets asked either!

Firstly, it is more than that. But yes, pictures of people in their underwear is a feature. Why? We live in a world of visual cues and visual judgements. This really isn't anything new - if you look at adverts through the past few centuries, especially for clothing, you'll find they were always aspirational. They were geared toward setting up a desirable ideal that the product could help you achieve, and that ideal was about putting across a certain image. Were you wearing the right style; were you the right shape? Corsets for men as well as women were promoted to help achieve the fashionable shape of the time. Between the 1930s and 1950s, adverts offering help in gaining weight abounded, as 'skinny' was considered unattractive. Not long afterward, opinion swung the other way and adverts to help you lose weight became more common.

So the question posed was, did you fit? And that's still the question. Cultures vary, but our tendency to judge on appearance is still prevalent. When people decide to disentangle themselves from those requirements, it becomes a public act of rebellion. When we decide to embrace our bodies that previously brought shame, we undermine that judgemental tendency firstly in ourselves.

Pictures in your underwear are not a necessity of self love and body confidence. Nudity does not empower everyone. But let's look deeper than the surface. What do I see when I look at the posts on The Body Confidence Revolution? Post-partum bodies. Post-surgery bodies. Bodies scarred by accident or self-abuse. Bodies of all shapes and sizes and colours and genders. Bodies belonging to people who are saying 'no more' to fear of judgement from both themselves and others. Bodies belonging to people who are learning to live in harmony with them. Bodies allowed to age as nature intended.

I believe there is more to us and to the role of body confidence than just that. I think confidence in one area spills into others. I think working to reduce the physical fixation will free us up to focus elsewhere. After all, isn't it who we are that matters most?

So why did I want to be involved? I've been thinking and writing about body issues for a long time. There are other things I care about too, of course - but this is one I come back to. My own experience and the things I've learned and heard over the years make it impossible for me to ignore. We live in our bodies; they dictate so much of how we experience life, how we feel, and, sadly, how we are judged - by ourselves and others.

Involvement with the eating disorder charity Tastelife has been one of the reasons I wanted to be an ambassador. It opened my eyes to a problem I knew about, but I hadn't until recently seen the extent of its influence. Eating disorders are life destroying, and so many are founded on or largely influenced by poor body image.

Social fixation on bodies and body ideals create a toxic environment in which eating disorders proliferate and flourish. Wanting to help people find a way through their disorder, to recognise some of those negative influences and tackle them, is part of my motivation. I know there are many routes of support for sufferers, but I hope this can be one.

I am also partly doing this because of my own experience: for who I have been and what I know. For the girl who got called 'fat Amber' and laughed it off but was hurt inside. For the girl who thought thinness was the answer, but remained unhappy. For the girl who was buying cream for her stretch marks at age 14.

For the woman who was a fat bride, a fat graduate, a fat wife and felt guilty about it. For the woman who was anxious before every social occasion for years, paralysed by fear of how people would judge her appearance. For all the times I was told to cover up, to sit down, to take off my heels. For when I was asked what I had been wearing when a customer sexually intimidated me. For when a former boss mentioned my breasts in front of clients.

For all the times I thought I had to choose between feeding my body and other people accepting it. For all the times I saw a photo of myself and shuddered.

But then again, not for me! Because my story might be mine, but I know from so many conversations that it isn't that unique, really. The Body Confidence Revolution is for you. I don't have all the answers, clearly! But if I can ask the right questions, if we can have an open discussion, and if we can work through stripping away the fear and judgement we've lived with, then that is worth the effort. And that's why I'm a TBCR ambassador.

Viva la revolution!