Teenager Chris Clark talks confidently to the large group of slimmers gathered in a Copnor church hall.
The college student seems relaxed and at ease with all eyes on him as he laughs, jokes, tells the group about his weight loss experiences and offers a few words of wisdom.
And mum Marguerite listens proudly, knowing how far her son has come in just under a year.
Chris has lost almost five stone, dropping from 16st 4lb to a trim and healthy 11st 5lb.
The weight loss has not only boosted his fitness, health and energy levels but improved his self-esteem.
In fact the 18-year-old says it has pretty much changed his life.
‘I wouldn’t have been able to talk to you like this last year and when I joined the group I didn’t want to say anything,’ he reveals.
One of the biggest bonuses of the teenager’s slimming success is that it has improved his mobility.
Chris had difficulty getting around because one of his legs had grown long than the other.
The problem is fairly common among young people and should rectify itself.
But the weight was causing him additional problems.
The teenager’s new confident manner is partly because he feels comfortable with the group, but Marguerite says that her son is also a far more outgoing teenager.
‘He goes out more. I used to be worried because he only had a few close friends and stayed in all the time. Now he’s more how an 18-year-old should be.’
Sitting by his side in the group, Marguerite is as proud of her son as he is of her.
They have achieved their impressive weight loss successes together and now Marguerite has hit her own target, losing 2st 8lb.
‘It’s wonderful,’ she says, beaming after receiving a Slimming World certificate. ‘We’ve lost a small person between us – seven-and-a-half stone.’
For Chris, it’s a far cry from last year, when he was unconfident, sluggish, struggled to walk for even 10 minutes and was too shy to speak in his first Slimming World group.
It was Marguerite who suggested they try to lose weight together after noticing how unhappy her son was becoming.
Chris admits to being fed up but plays down his distress. But Marguerite was worried about him.
‘His exam results hadn’t been good and he had a bit of a meltdown, it was “my weight, my legs, my exams”. So I said you can take your exams again and if we do something about the weight, it will help with the legs.
‘And I thought I could do with losing a few pounds, so why not?’
As a young lad, he also wanted to be trim, wear nice clothes and fit in with his friends.
‘I used to feel like I was different, I felt like I stood out because I was bigger and couldn’t always do the same things, shop at the same stores or wear the same clothes.
‘If someone said do you want to go out tonight or go out for a bike ride I’d say no.’
Slimming World consultant Vanessa Steenton says: ‘The great thing about Marguerite and Chris is that they have done it together. The support and encouragement they give each other is very important.’
Chris says the final straw was when he expanded beyond his 44-inch waist trouser.
He had also suffered bullying through school, although he says ‘I gave as good as I got’.
But Marguerite says it did upset him and he would go home and raid the cupboards for comfort food.
The first day at Slimming World was a big step for the teenager. He was the youngest in the group and one of the only males.
But he fitted right in and feels so confident now that he’s aiming to become a consultant. ‘I’d like to do it because Slimming World has helped me so much,’ he says.
Chris’s diet of sausage rolls, crisps and sweets before lunch, sandwiches, dinner and then evening snacks like biscuits has been replaced by cereal and fruit, jacket potatoes and beans, salads and healthy meals.
For his efforts he was voted Young Slimmer of the Year in his group and went to the contest final in Derby.
The Portsmouth teen wasn’t crowned winner of the competition, but didn’t mind as he had the chance to meet Rebecca Adlington.
The media student wrote about Loose Women for his coursework and became a fan of Rebecca when she joined the TV show.
One of the biggest bonuses of Chris’s weight loss is that he no longer needs physiotherapy, although he makes sure he improves muscle tone in his legs by going to the gym.
Marguerite says she has been amazed by his success. ‘I didn’t think he’d stick to it as it’s not easy, so I’m really pleased and proud.’
Chris admits that mum giving him £5 for every half-stone lost has gone some way to helping.
Now he’s learned to cook and is proud to be a Primark size small (‘that means it really is small’), is happier at college and is aiming one day to be a science teacher.
Of course he has treats and likes to go out drinking with his friends sometimes. But he’s keeping the weight in check and becoming more active.
‘I even thought about doing sport at college. What’s happening to me?’ says Chris laughing. ‘I didn’t in the end, but the fact that I was thinking about it was quite crazy.’