Determined Sara Roper, 31, shed the pounds after joining Weight Watchers in Ashford three years ago.
Within two years, the mother of two went from 18 stone six pounds to a slim 11 stone four pounds.
Sara before the weight loss
Mrs Roper, from Willesborough, said: “I was in denial before, but hearing that it would be difficult to hear my son’s heartbeat because I was overweight was the shock I needed.”
As well as sticking to a diet and attending weekly meetings, Mrs Roper took up running and cycling in order to get fit.
She has now been at her goal weight since February last year.
Sara Roper has lost 7 stone
She added: “I’m still getting used to my new weight. I haven’t been this slim since I was at school, so this is the first time as an adult that I’ve felt like this.
“When I try on clothes it is still a shock sometimes that they fit.
“Even when I was at the cinema the other day, I thought to myself, these chairs are really big, but before it was me that was so big.”
Sara can easily fit into her old clothes
Mrs Roper says she chose to join Weight Watchers because the diet suited her lifestyle.
"Hearing that it would be difficult to hear my son’s heartbeat because I was overweight was the shock I needed" - Sara Roper
She added: “It doesn’t feel like a diet. You can still eat what you enjoy, but in moderation.”
Mrs Roper’s Weight Watchers leader, Michelle Lockyer, said: “I feel very proud of Sara.
“She has gone from exercising in a graveyard so no-one would see to running six miles in a go and cycling 35 miles.
“She has also joined a karate club with her daughter. She is a true inspiration.”