A mental health trust has been featured in a filmmaker's newest documentary which will air this weekend.

Louis Theroux's new documentary, focusing on anorexia, will air on October 29 on BBC2 and will feature interviews and footage taken from the Barnet, Enfield and Haringey Mental Health NHS Trust, where Theroux spent two months filming with his crew.

One of the patients who takes part in the film, Rosie, is treated at the trust's St Ann's Hospital in Haringey for anorexia.

She said: "I wanted to take part in the film to show people what it is like to have an illness like Anorexia. I wanted to show how it can take over your life, and that it’s not just about food.

"It’s about your mind controlling you, and it can be a real nightmare, affecting your life and your relationships particularly with your family."

Louis Theroux spends time in BEH’s St Ann’s Hospital and Vincent Square Clinic run by Central and North West London Foundation Trust, meeting patients of various ages and in various stages of their illness, accompanying them through an enforced daily routine which includes scheduled eating and group therapy sessions.

Maria Kane, the trust's chief executive, said: "We are delighted that Louis has decided to take a close look at eating disorders for his latest film.

"It’s incredibly important that people understand and empathise with anorexia which is a very debilitating, misunderstood and dangerous illness.

"Our eating disorders service provides specialist care for very vulnerable patients and our aim is to treat people as early as possible both in hospital and in our community outreach programmes."

Around one in every 250 women are affected by anorexia in their lifetime, as well as increasing numbers of men, and in recent years the number of people admitted to St Ann's because of their condition has risen dramatically.

Louis Theroux on Anorexia will air on BBC2 at 9pm on October 29.