A customer service advisor from Abergavenny is set to achieve her dream of running the 2026 TCS London Marathon for charity after her 11kg weight loss. 

On top of losing the equivalent of 11 bags of sugar, Bethan Griffiths, 29, is now representing Slimming World in their official marathon team at the iconic TCS London Marathon.

Bethan is running for Cancer Research UK in memory of her grandparents and aiming to increase awareness of how keeping a healthy weight and moving more can improve people’s health and help reduce the risk of developing 13 types of cancer.

Bethan began gaining weight as a teenager, spending her pocket money on sweets and chocolate on the way to school. At home she’d eat sugary cereals or toast before her evening meal, which would be comfort food served with bread and butter.

 Bethan says, “Being overweight has always been more about my confidence and the way I presented myself to the world through my clothes, tattoos and accessories. I was very insecure and found it difficult to make new friends.

“My final straw moment came when I needed double jaw surgery. During the Covid lockdowns I put on a lot of weight, and my orthodontist told me my BMI was almost too high for them to perform surgery. I was self-conscious of my crossbite, so to be told I potentially couldn’t have the procedure due to my weight was devastating. I knew then I needed to change my ways.”

Bethan added, “I wasn’t active at all before joining Slimming World. I live near mountains and would climb one maybe once or twice a year, but it always left me very out of breath. I hated walking anywhere and saw any form of exercise as a chore and sometimes even a punishment. Slimming World helped me build up my activity levels gradually and I’m always working towards my next goal. I started walking to get my steps in and eventually gave running a go. It has improved my fitness and had a positive impact on my mental health.

“I’ll be running the London Marathon and raising money for Cancer Research UK, in memory of my grandparents who sadly passed away from cancer. My family has always given to cancer charities, and I can’t think of a better way to do my bit than running my first ever marathon – the iconic London Marathon at that – in aid of one!”

Slimming World Consultant Shelly Willetts runs weekly group sessions in Abergavenny and says, “Bethan is a true inspiration to us all and we are so proud of her. When she first came through the door, she wanted to lose weight to feel healthier – however, she had no idea she’d go on to run the London Marathon! She is proof that when you believe in yourself, stay determined, and are supported by people who understand your journey and care about your progress, your weight loss and fitness dreams can become reality.”

Money raised for Cancer Research UK and Alzheimer’s Research UK helps fund life-saving research. Anyone who would like to sponsor Bethan can do so by visiting her fundraising page.  

Shelly’s Slimming World groups are held every Monday and Tuesday in Abergavenny. To join, call Shelly on 07980259638.