The 26-year-old dropped from almost 19 and a half stone to 14 stone after getting engaged and deciding that she didn't want to regret her wedding photographs.
As soon as she got engaged to her partner Will, she started her weight loss journey by signing up to Slimming World, swapping processed food for healthy, homemade alternatives.
Becky also hated getting on aeroplanes, as she was terrified that she would need a seatbelt extension or would not be able to fit comfortably on the seat.
Following her loss of five stone, she decided to sign up to run the 10 mile event.
The event is something that Becky has always dreamed of doing, but always feared being too overweight to be able to complete it.
After her weight loss success, it was first on her list of goals for 2018.
Becky, who works as a primary school teacher, said: '˜I decided to lose weight for my wedding which takes place in August as I always said I wanted to be able to look back on my wedding photographs and not have any regrets.
'˜I used to be a very self-conscious and anxious person. I wouldn't want to go out with friends or family because of the way I looked and I always struggled on school trips as it would make me very tired.
'˜Getting on a plane used to be such a worrying experience for me because I was worried that the seatbelt wouldn't fit.
'˜When I got engaged I started Slimming World. I used to skip meals through the day or snack on chocolate, crisps and white bread.
'˜I'd then think nothing of calling at McDonald's on my way home from work and then still go home for dinner!
'˜Now I try to cook from fresh by having soup with vegetables and fruit as a snack.
'˜As I started to see progress with my weight loss, I decided to sign up to the Simplyhealth Great South Run as a goal to keep me going.
'˜I've always wanted to take part and run 10 miles, but I was too afraid because I thought I was too overweight.'