Independent living often feels like the only show in town for adults with learning disabilities these days.

So the idea that a 22-year-old woman with Down's syndrome is told by her parents that she can't carry on living in her shared home with her fiancee, but must move back in with them, seems anathema.

That is one of the scenarios explored in a BBC documentary about young people with learning disabilities looking for love and relationships, to be aired next week.

Seeking Someone Special looks at the story of Natasha Connon and her fiancee James sensitively, and also features Natasha's parents explaining why they took the action they did.

In her first 14 months of independent living with James, who also has learning disabilities, an inability to manage healthy eating saw their daughter's weight soar, taking her from a size 10 to a size 22. "It was like self-destruction in front of our eyes," her father says. His wife adds: "I'm not trying to interfere, I'm really trying to help, so she lives a long, happy and healthy life."

During the time cameras were filming, Natasha met a target to reduce her weight from 14 stones down to her normal 8.5 stones, and was allowed to move back in with James, who she is due to marry next year.

The documentary is frequently moving, as when Natasha tries on the wedding dress she has dreamed of and is literally given permission to cry by the fitter, whereupon she buries her head into James's shoulder.

The film also explores the frustrations of two young men with learning disabilities who are struggling to establish relationships, and the anxieties of their parents. Richard Brownlie, 25, from Larkhall, who has Asperger's syndrome, is enthusiastic and affectionate but his lack of understanding of social situations and hyperactivity can be a hindrance. He ends a relationship with one girlfriend and tells his mother about her reaction. "She got upset, and angry and cheeky," he says, with a note of surprise.

Peter Bowers, from Glasgow, a DJ with ADHD who is affected by foetal alcohol syndrome, also features. He has yet to see the film, but said he didn't mind having the cameras follow his – thus far unsuccessful – search for a girlfriend. "I was up for it from the start," he explains. "I hope I'll get offers of DJing work, and get famous and noticed by friends and family."

The focus is a club night at the Arches, in Glasgow, for people with learning disabilities. The first of its kind in Scotland, it was launched in April based on similar successful nights in Leeds and London. The second Glasgow night is scheduled to take place on October 4, while the event has spawned an Edinburgh twin at the Voodoo Rooms.

Robert Gallagher, project manager at independent living charity C-Change, said the night had been more popular than hoped. "It is aimed primarily at people with learning disabilities, to let them be part of the clubbing scene, although anyone is welcome," he says.

Club nights run from 7.30pm until midnight. Despite initiatives such as the Stay Up Late campaign it can still be difficult for people with disabilities to get carers late at night. Strathclyde Police provides plainclothes officers to ensure vulnerable party-goers make it home safely.

"There were nearly 300 people at the first night, including some from Edinburgh who have now started their own club night," Mr Gallagher says. "If you are aged from 18 to 25 then clubs tend to be a big part of your social life and how you meet people. We are replicating that environment and if people want to pull each other that is fine."

Seeking Someone Special is on BBC2 on Monday at 9pm.