It had been a wonderful evening and now it was ruined – by a photo that my husband, Dean, had posted on Facebook. I was shocked by how big I looked and begged him to delete it. ‘It’s the only photo we’ve taken all holiday,’ Dean said. ‘Besides, you look fine. I’m not deleting it.’ For the rest of our holiday I covered myself up, even wearing a T-shirt over my swimming costume.

A few weeks later, I spotted Dean had left his phone on our living-room table. Heart racing, I opened up Facebook and quickly removed the photo. Now the evidence was gone, but it made me realise something – I needed to make a change.

I went online looking for a weight-loss plan – one I hadn’t already tried in my years of yo-yo dieting – and found a Slimming World group near me that evening.

Dean agreed to support me and as we walked into group together, I felt pretty sceptical. Since being diagnosed with an underactive thyroid about 11 years before, I’d felt like I was doomed to struggle with my weight forever. After listening to the Consultant, Leigh, explain Food Optimising, we decided we’d try it… just for a week.

I made us healthy versions of our favourite dinners, such as southern-style chicken cooked using low-calorie cooking spray and served with Slimming World chips. I made baked oats for breakfast with my Healthy Extra oats and had Slimming World quiche and salad for lunch.

After a week, we stepped back on the scales to find I’d lost 4lbs and Dean had lost 7lbs! I realised then that I could actually do this.

Week after week we both lost weight and felt more energetic. Before, when our grandchildren had visited, we’d sit watching TV as they played on their tablets – now we all went cycling along the canal or walking on Dartmoor.

There were times when the scales didn’t move, or I had a small gain, and that’s when Leigh was at her most supportive, helping me to focus on the week ahead.

In Costa Rica last February, wandering along the beach in my swimming costume, I smiled at Dean as he took my photo. And when we got home, it wasn’t just the lovely comments on Facebook that made me feel good about myself. I’d stayed on track all holiday, and lost 4lbs.

After years of believing my underactive thyroid was stopping me losing weight, getting down to my 9st 11lb target felt like such an achievement. Dean has lost 4st 8½lbs, too, and our three children are over the moon for us. I feel like I’m finally living life to the full, and I love it…

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