Lesley Miller, 21, shared her picture with the Love What Matters Facebook page, explaining why the act of stepping in to her swimwear was so important to her, and the response has been incredible.
'I've spent the past 18 years of my life waiting,' she wrote.
'I kept my body covered up and hidden away. I told myself that one day I would finally let myself be seen; I would finally do all of the things I dreamed of when I was enough. Thin enough, happy enough, confident enough. When my body looked the way that it was 'supposed' to.'
Accompanied by a picture of herself smiling and posing in a two-piece, Lesley tells the story of her weight loss journey, and the impact it's had on her life.
'When I was three my classmates asked why I was so much bigger than them. Why I didn't wear the same smock they did.
'When I was seven, I lied to the lady at Weight Watchers, desperate to sit in on meetings full of middle aged women trying to shed a few pounds.
'When I was nine I went to weight loss camp and stood in line the first week to take my "before" photo.
'When I was eleven the surgeon cut into my stomach, and he told me how happy I would finally be. I was the youngest person to have weight loss surgery.
'When I was fifteen, I started cutting into my own skin. I thought I deserved it.
'When I was twenty, I lost half my body weight in nine months, my worth for the day solely determined by the number on the scale being lower than the day before.
'And then I got tired of waiting.'
Lesley adds that the bikini she's wearing in the photograph is the very first bikini she's ever bought, and the pride on her face is clear to see.
'You can see it all. Weird bulges and rolls of fat. Hanging excess skin. Stretch marks, cellulite, surgical and self harm scars. Awkward protrusion on my abdomen from my lap band.
'I want to learn to love all of myself, not just the parts I've been told are "acceptable." Because the secret is, I was always enough. And you are too,' she concluded.
Since it was added to the Facebook page on 3rd June, Lesley's post has received more than 30,000 likes, and hundreds of supportive comments from wellwishers.
'You are a beautiful woman... Obviously just as much inside as out. You go & rock that bikini my pretty friend!!!' one wrote, whilst a second agreed, 'You are stunning! Your strength and confidence make you even more beautiful! I admire you so much!'
Another added, 'After reading so many post lately, regarding body image, and why someone of a certain size, shouldn't wear certain items, this is a very refreshing post to read. Lesley, you are beautiful, with a beautiful heart, and body. Keep being you, and never let anyone bring you down.'