LOWRI Turner has waged a lifelong battle with yo-yo dieting. For 20 years, the 5ft high TV presenter shuttled between a size 10 and 16 – and every dress size in-between.

But upon turning 40, the mum-of-three decided to take control. Now trained as a nutritionist and hypnotherapist, she combines the two disciplines to help others do the same.

The 46-year-old is running a hypnotherapy for weight loss course at The Laboratory Gym in The Avenue, Muswell Hill, which involves tackling issues like comfort eating and portion control while in a hypnotic trance.

She says: “I got to 40 and wanted a new chapter in my life. I wondered what I was going to do for the next 20 years. Nutrition had always interested me because I struggled with my weight in my teens and 20s and spent my adulthood going up and down by three stone.”

Life hasn’t been easy for Turner in recent years. In 2007, she split with her second husband just months after their daughter Ariel was born.

Working to support her family by day, she pulled all-nighters to complete her nutrition studies. But while she found the anatomy and chemistry tough going, once she started seeing clients, it all fell into place.

“Interviewing people, listening to them and learning are the same skills as journalism, the only difference is that I had to learn to shut up.”

Turner, who once appeared on reality TV programme Celebrity Fit Camp, says it’s an advantage that she has “read every diet book going” and understands the compulsive behaviour that once made her a 50-a-day smoker.

“I know from experience, handing people a diet plan and expecting them to follow it is unrealistic. You have to help them change their behaviour around food.”

That’s where the hypnotism comes in. After years of radio broadcasting (she stands in for Vanessa Feltz on BBC London), she knew how to use her voice as a tool. She claims hypnotherapy and Neurolinguistic Programming can “reset” the triggers which lead to unhealthy cravings.

“The mind is very powerful and the effect of food on the brain is so important. If you aren’t properly nourished, you can become depressed and the foods we crave, like pasta, potatoes, ice cream and cheese all contain exorphins, an addictive morphine like substance which has a similar effect on the brain. To get people off grain and dairy products, you have to do hypnosis, to make them believe they can manage without them.”

As well as regular appearances on The Wright Stuff, writing for women’s magazines, Turner has a regular spot as Grazia’s nutritionist, holds a clinic just off Harley Street and sees clients at her Muswell Hill flat.

“Seventy-five per cent are women. They come for weight loss but many have other problems: depression, anxiety, stress or thyroid problems. You have to treat the whole person. Hypnotherapy can be a good place to start.”

Turner has stabilised her own weight to a size 10/12 by giving up dairy products, quitting smoking, alcohol, most wheat or grains and making regular gym visits.

But aged 24, as a young fashion editor on the Evening Standard, it was a different story.

“I was the only plump girl in a very thin industry but at least the fashion houses couldn’t bribe me with clothes.

“Everything else in my life I could do really well, yet I couldn’t control my weight. I see so many successful, hardworking people like that – food is an escape valve and their vulnerability, distress and anger comes out in that one area. You have to try to find other ways to express that without swapping one addiction for another.

“You are on such a high when your weight’s down, you get lots of attention from men, but it’s easier to put on than to lose it and it becomes so time-consuming, worrying about your weight and counting calories.”

Turner acknowledges the huge pressure for women to be thin and believes weight is a “multi-layered” issue linked to body confidence and self esteem.

“No-one loses weight when they feel bad about themselves – when I am stressed out I eat my worst. We all know what we should be eating yet we can’t do it because if we are tired or stressed or in need of a treat we can’t be rational about food. I’m about giving clients the confidence to feel they can stick at it.”

Turner, who grew up in Archway, recently moved back to north London because of its schools.

“I vowed I would never live here because it’s too suburban but I’ve had enough of edgy and urban. I’d be lying if I said I have found the promised land. I still have to watch what I eat but I feel so much better.”