He had ballooned to 17 stone by the time he was 16 years old.
But by dropping his unhealthy lifestyle – which saw him gobble takeaway pizza for lunch – he managed to get fit enough to join the Royal Marine corps in just 12 weeks.
The Wiltshire lad also credits his transformation with finding the love of his life, fiancée Emma, after never having a girlfriend at school.
At his heaviest, he said, he was too shy to even talk to girls, saying the thought of approaching a girl ‘sent shivers down his spine’.

While at school James was loved by his mates for being the class clown, but he said behind the facade lay a ‘miserable’ teen whose self-esteem was so low he even refused to go swimming.
After pushing himself to the limit to meet the Royal Marines’ strict fitness requirements, James was a member of the service between 2011 and 2015.
He said the entire time he was a Royal Marine, he was always focused on his next goal – opening his own gym.
Two years on and he is now the owner of Sui Generis Gym in Pewsey, Wiltshire.
James said: “It feels great to share in other people’s weight loss transformations, and been through my own makes it easier to relate to what people are going through.
“I couldn’t be happier.”