On a girls’ trip to Goa, India, I realised something had to change. I was with my mum and aunts, and we were having a lovely time. On the last day, we decided to do some shopping. I finally saw a dress I liked – a blue and white tie-dye maxi dress. It wasn’t fashionable, but for me it ticked the boxes that mattered most – it was long, voluminous and covered up my shape. It was just what I needed for a friend’s wedding later in the year.

Back home, I uploaded our holiday snaps to my computer – and didn’t like what I saw. I hoped the first picture was just taken from a bad angle, but the next shot left me with the same sinking feeling. Hiding under my layers in the Goan heat, I looked awkward and uncomfortable.

I started gaining weight at 15, when I gave up competitive swimming. While my exercise dropped dramatically, the amount I ate didn’t and I crept up four dress sizes.

At one point I joined Slimming World with Mum, but I didn’t stick with it. Instead, I tried to slim on my own. One day, I’d be on a ridiculously restrictive diet; the next I’d be out drinking with friends and rounding off the night with a kebab and cheesy chips. I did eventually lose some weight, but I felt awful.

Soon after meeting my partner, we got talking about going travelling – and soon we were partying our way around a backpacking trail. It was easy to stop thinking about the calories when we were having so much fun.

Two years later, we came home and my party lifestyle gave way to comfortable routine. I took an office job, skipping breakfast, and running on biscuits and mugs of sugary coffee all morning. At lunch, I couldn’t resist the local takeaway’s sweet chilli chicken wraps, with fries, barbecue sauce and a fizzy drink. In the evenings, I’d cook burgers with full-fat mince or order in a pizza.

Now, seeing the pictures of myself in Goa gave me a shock. ‘I’m going back to Slimming World,’ I told Mum – and she said she’d come with me for support.

When Mum and I walked into group that first night, I immediately saw a face I recognised. It was Sue, the lovely Consultant who’d helped me as a teenager. I took a seat and felt immediately at ease. When I found out I weighed 14st 2½lbs, somehow I was even more determined.

I planned out my meals for the next week. For the first time in years, I ate breakfast – usually a bowl of overnight oats with berries. At lunchtime, I had smoked salmon salad or couscous with leftover cooked veg. I loved being able to use my Healthy Extras for things like cheese on my home-made lasagne or Hi-fi bars for pudding. I made Food Optimising versions of our favourite our favourite takeaways, as well as my famous tasty burgers.

I was amazed when I found I’d lost 3½lbs in the first week. I made sure I went to group every Tuesday night without fail.

Then, one weekend, I went away for my friend’s hen do and found it hard to stay on plan. At my next weigh-in, I’d gained 2½lbs. I was so upset with myself that I ran straight out to the car. Then, a little voice inside my head said, ‘No, Polly. Get back in there!’. And I did.

I got back on track and as the weeks flew by, the pounds flew off. Within a month, I’d received my one-stone award. People around me were amazed at how quickly my weight loss began to show in my spirits, too.

I no longer felt winded climbing the 40 steps to our flat and I started taking my dogs out for longer walks. I knew every bit of extra activity made a difference. And I wasn’t the only one reaping the benefits. Just by eating what I was at home, Mum had also lost a stone.

Six months after joining group, I reached my target weight. It made me realise how unhealthy the yo-yo dieting had been. The biggest difference is that I’ve learnt not to be hard on myself if I go off track – I know that as long as I go straight back to Food Optimising, anything I’ve gained will soon come off again.

With a wedding just around the corner, I had one important thing left to do. The maxi dress I’d bought in Goa swamped me, so I spent a whole day shopping... until I found the perfect body-hugging, powder blue Bardot dress.

As I posed for photos with the beautiful bride, there was no worrying about what I was wearing, how I looked or what other people might be thinking. At last I feel happy in my own skin – and I’ve done it the healthy way.

*Weight loss will vary due to your individual circumstances and how much weight you have to lose.