Walking along the beach with my sons, feeling happy and confident in a size six bikini, I reflected on the woman I’d been just 16 months before.

She would never have believed me if I’d told her one day she’d shed the flab that had plagued her all her life, and have a body like her Hollywood girl crush, Margot Robbie.

There are times when I can scarcely believe the transformation I’ve undergone, and in this era of GLP-1 jabs and surgery, I’ve done it all myself through healthy eating and exercise.

At my heaviest, I weighed just over 15 stone and hid my body away, ashamed, under size 22 clothes.

I was the ‘fat, funny friend’ and I assumed I always would be. After all, I’d spent a lifetime being ‘big’, it was all I knew when it came to my identity and how others saw me.

I grew up in Cheshire and at school I was teased constantly, the butt of cruel jokes about my size. I had friends but was always cast as ‘the funny one’ never ‘the pretty one’ or ‘the one the boys fancied’. I’d laugh along to save face, but inside I was hurting.

My parents showed their love for me and my siblings through food, and we always had to finish everything on our plates no matter how full we were. I’d eat the foods I didn’t like first so I could ‘save the best for last’ – like sausages and pudding – which meant even when I was full, I’d keep eating.

Over time, I stopped listening to my body completely and had no off switch.

I’d snack constantly, Crisps and biscuits were my go-tos, and food was my emotional crutch. Sad? Eat. Happy? Eat. Bored? Eat. It was woven into every part of my life.

After school, I went to work with horses. It was a physical job, grooming and mucking out the stables, but I’d come home and stuff my face with crisps and chocolate, so I remained overweight.

I still remember how humiliated I felt one day when a colleague told me I was too heavy to sit on the horse I was meant to train. It didn’t prompt me to try to lose weight though, rather I comfort ate yet more junk to make myself feel better.

Any scenario where my size could be scrutinised made me anxious.

I loved visiting theme parks but would always stand in the queues gripped with nerves that I’d be told I was too big for the ride. I was never turned away but staff would always ‘double-check’ that my seatbelt fitted, which was mortifying.

In 2010, when I was 20, I met Oliver, the same age as me. I was working as a groom in the stables in his village and we bumped into each other in the local pub after work.

I was a size 18 then and weighed around 14 stone – Oliver was on the large side, too, but that didn’t matter to us.

We enjoyed nights in with a greasy takeaway and a bottle of wine, cuddling up on the sofa.

Kebabs were our favourite and the delivery driver would joke ‘See you tomorrow’ and we’d laugh, because we both knew he was right!

Neither of us was self-conscious about our weight though – we just both loved food, fancied each other and enjoyed a laugh. It really was that simple.

In 2011, I became pregnant with our eldest son Henry and moved from Wiltshire to Manchester for Oliver’s job in tech. Lonely and exhausted with a new baby, as ever I turned to food for comfort.

By 2013, though, I desperately wanted to lose weight because I just hated feeling like a blob, tired all the time. I tried everything – from Slimming World and intermittent fasting, to the keto diet and meal replacement shakes – but could never stick to it.

Every diet felt restrictive and miserable, and I always ended up back where I started, devouring white toast with butter and jam, pizza for lunch and a curry in the evening, topped up with chocolate and crisps throughout the day.

By the time Hugo was born in 2018, I was a size 22 and my confidence was at rock-bottom. I avoided social events and refused to be in photos, even ones with my children. I hated myself for it but I hated how I looked and felt even more.

By late 2023, I’d reached breaking point. My mental health was shattered, my joints ached and I struggled to keep up with the boys

I was only 34, but I began to worry that if I carried on this way, I wouldn’t see them grow up.

I knew that quick fixes and fads hadn’t worked in the past; if I was serious about transforming my body and health I needed to learn about nutrition and how to lose weight healthily and sustainably.

I enrolled in a number of online courses to educate myself and for the first time, I started to understand calories, protein and portion sizes. I realised I didn’t need to starve or ban foods. I just needed a sustainable plan.

In January 2024, I began weighing my food and tracking my calories. I began on 2,100 calories a day and gradually reduced that to around 1,600 as I lost weight.

Nothing was off limits. If the kids fancied a McDonald’s for a treat, I’d join them but opt for a salad instead of my usual Big Mac meal.

When we ate together as a family at home, I’d still tuck into spaghetti bolognese, I just had a smaller portion.

Out went my sugary cereal in the morning, replaced with Greek yoghurt with granola and I found I no longer wanted a cheese toastie and crisps for lunch, preferring a chicken breast with broccoli and rice.

By September 2024, I’d lost four stone, dropping from 15st 1lbs to 11st 1lbs and a size 22 to 12 – and it had felt easy. I wasn’t dieting, I was just eating differently.

Oliver then decided to join me. He weighed 17.5 stone at that time and my success inspired him. We began meal-planning together, going for walks and supporting one another to make good choices if we went out to eat.

By Christmas 2024, I was 9.5 stone and a size 8, and Oliver was 15.5 stone. We both felt fantastic but I wasn’t done yet.

I loved Margot Robbie in the Barbie movie and googled her weight – which was 55kg, or 8st 9lbs.

‘Could I slim down to the same size as her?’ I wondered. I told Oliver I wanted to be ‘Barbie Sophie’ and he thought I was bonkers, but I was determined.

By April 2025, after 15 months following my new lifestyle, I hit 7st 7lb and a size 6.

By then, Oliver had lost 5.5 stone and was a svelte 12st 7lbs.

Together we’d lost 13 stone.

A year on, we are both maintaining our weight through healthy eating and exercise – I’ve joined the gym and now love lifting weights. I want to be strong, not just slim.

Inspired by my own experience, I’ve created a weight-loss app called Calocoach (www.calocoach.co.uk) to help others track calories, protein and progress. I’ve got clients already. As a qualified health coach, it feels incredible to help others break the cycle I was once trapped in.

Last July, on holiday in Catalonia, Spain, I didn’t hide my body away like I used to. I played with the boys on the beach and smiled for photos in a size 6 bikini.

My boys tell me I am unrecognisable and that makes me happy. I never want to go back to how I used to be – tired, unhealthy and unhappy. I missed years hiding away. I’ll never get them back. But now I’m making every moment count.

As told to Matthew Barbour