Many of us waking up will feel the familiar pang of New Year’s Day self-loathing and decide that this is the day to start that new diet, begin that new detox, finally attempt to get the body of our dreams. Within a month we will probably feel miserable, hungry and no closer to achieving our goal.

Now a new film is set to challenge the increasingly pervasive message that there is one way to look by tackling the myth of the perfect body and the celebrity culture that fuels it. Embrace follows Australian writer and campaigner Taryn Brumfitt as she travels across the world talking to a huge variety of women about how they see themselves. She speaks to actor and talk-show host Ricki Lake about body image and Hollywood, to an entertainingly direct Amanda de Cadenet about what it was like living with tabloid scrutiny at the age of 18 (“The message I took from it was that if you were thinner you were better … these days I’d say if you want to eat the biscuit, eat the fucking biscuit”) and to Harnaam Kaur, a British Sikh woman who celebrates the beard caused by polycystic ovary syndrome rather than break her religious beliefs.

Most movingly of all, the film introduces us to women who have seen their bodies change in dramatic ways, from Kirsty who lost a breast to cancer (“My boys think it’s cool, they’ve got a mum with one boob – it’s a bragging point”) to the inspirational Turia Pitt who suffered burns to 65% of her body when she was caught in a bush fire and who admits: “I’ve gone through something so huge … and I think, well, if I’ve managed to start my life from scratch then I’m not sure why other people can’t. That probably sounds a little bit harsh but it’s just how I feel.”

“I made the film because I really wanted to have a conversation about this,” says Brumfitt. “I felt as though a lot of people behind closed doors felt the way I did – that they were being pressured to look a certain way and I wanted people to know that they’re not alone.”

Brumfitt knows the price of striving for perfection. After the birth of her third child she became obsessed with regaining a pre-pregnancy figure and began a punishing weight-loss and exercise regime that culminated in competing in a bodybuilding contest. But despite having what society would claim was the perfect figure, she was desperately unhappy and decided to return to a more relaxed regime. One day she posted an online before-and-after picture, with a twist. The before picture was her at her thinnest, the happy after shot was Brumfitt as she was, carrying a few pounds yet content.

“I thought it might help people but the response was mind-blowing,” she says. “It went viral and became this internet sensation and suddenly I found myself doing media across the world and talking about how women see their bodies.”

Brumfitt swiftly realised that the brief chats she was doing on morning television were only scratching the tip of a very large iceberg. She started up the Body Image Movement to provide a forum for discussion but still wanted to do more. “I was hearing from all these women from all over the world and I knew this was a subject that needed a bigger platform so I nonchalantly thought, ‘Oh, I know, I’ll make a documentary, how hard can that be?’ And of course the answer was very.”

It might have been hard but the result is compelling. Embrace delves into every aspect of body image pressure from the plastic surgeon who spends a large amount of time telling Brumfitt that her post-pregnancy nipples “should be up here” (“I took one for the team there,” she remarks drily) through the magazine editors who talk frankly about the way in which the perfect body is sold to the world. There are screenshots of the body shamers who contacted Brumfitt online after her pictures went viral, telling her she should be ashamed and that her husband must be devastated.

“I really gave the audience the parental guidance version of that,” she admits with a laugh. “It bothered me at first but then I realised what’s the point? I feel great about my body. The more shocking thing was that no matter where I went in the world, body shaming and body hating was everywhere. It was like an epidemic and I found that heart-breaking and mind-blowing.”

Certainly one of the most powerful moments in the film comes when Brumfitt asks women across the world how they feel about their bodies. They are a range of ages, body shapes and nationalities yet they all say they’re unhappy with how they look.

“I feel as though I’m drowning in a sea of media,” announces a distressed mother talking about how hard it is to convince her teenage daughter that she doesn’t have to look a certain airbrushed way – and Embrace is at its strongest when it tackles how we collude in this objectification.

“We live in a world where women are objectified and sexualised in advertising campaigns or on television on a daily basis,” says Brumfitt. “I really do hope that this film allows us to keep pushing back against the toxic ideal of perfection.”

She has already had positive responses from some unlikely sources. “Quite a few men who have seen the film have contacted me and been so beautiful,” she says. “They’ve said things like, ‘I’ve told my wife for ever that I love her the way she is and I just don’t care about all the things she’s so worried about’. And that’s important because I don’t think this is just a women’s issue – it’s a problem for humanity.”

Indeed, although Embrace was “made for women first and foremost”, Brumfitt says she’s increasingly aware of how many young boys are also suffering from body image problems.

“There have been so many studies recently on the use of steroids in teenage boys – they’re under pressure to conform to a certain kind of muscled, manly stereotype as well and they’re equally bombarded with images of how they should look and behave.”

Her main hope is that the uplifting Embrace will convince audiences to start treating their bodies as something to love rather than loathe. “Absolutely. We need to detox from the toxic messages we’ve allowed inside our minds for so long,” she says. “I want people to know that they do have a choice: you can either spend your life being at war with your body and hating it, dieting, shaming yourself, using exercise as punishment, or you can embrace your body, move it for pleasure and live an exciting and uninhibited, liberated life. I know which one I’d choose.”

Embrace will be available in cinemas across the UK from 16 January