BIG ratings: Overweight and on TV

Yet another reality TV series about obesity starts this week. Are these programmes tackling the problem, or only an excuse to laugh at fat people and ignore our own problems? Julia Stuart reports

"I've had to wear a thong today because I couldn't find my normal knickers," whimpers 23-stone Stacey Pinnock, emerging from a tent. "I'm going to have chef's arse again by the end of the day. It's when the sweat trickles down your back into your crack, and it rubs and gets all sore."

The 22-year-old is one of eight of the "fattest people in Britain" chosen by Channel 4 to attempt to walk 500 miles from Devon to Edinburgh in an attempt to get fit and lose weight.

Too Big To Walk?, which starts tomorrow night, sees participants clambering over styles, snacking illicitly and bickering over who's going too slow, to say nothing of the sniping provoked when 22-stone Alice Duxbury checks into a hotel one night rather than staying in a tent like everyone else.

"Fat people are full of bloody excuses," mutters 22-stone Adam Van Gogh, who admits to having wasted a decade being a "fat, lazy, fucking bastard". Only half of them complete the eight-week journey.

Gary Baines, 45, who weighed 24st 4lb at the beginning of the journey, was simply trying to stay alive. "The doctor said I needed to sort myself out as I was heading for a heart attack," says the accountant from Hapton, Lancashire.

Baines, who lost 3st 4lb on the walk, wants the series to inspire overweight people to become active. "I would have liked the chance to have done it without the cameras being there, but I trusted the crew and the production team to put something together which wouldn't make us a laughing stock. I'm pleased I went on it - but ask me again when it comes out."

Pinnock, from east London, works as temp. She signed up to be able to fit into more flattering clothes and "attract better looking guys". She also reached Edinburgh, shedding two-and-a half stone along the way, weight she has kept off.

She, too, had hopes of being an inspiration, but now doubts it. "On the walk there were people who were giving us abuse. At one point there were grown men shouting out 'fat bastards'. I've never had that before. I think people will just laugh when they watch it. I don't think the Great British public will realise how much heartache we went through and how much pain we were in."

Jane Thompson Smith, 41, pulled out after a week because she developed cellulitis on her legs, a skin infection that can be life-threatening. The 23-stone chartered accountant from Middlesbrough wanted to lose weight to be in the best shape to conceive. " Hopefully we'll smash a few prejudices," she said.

Nigel Denby, of the British Dietetic Association, is doubtful. "I don't think that very, very overweight people trying to walk from Devon to Edinburgh is going to necessarily inspire the rest of the 50 per cent of the nation with a weight problem to make any real advances in changing their lifestyle," he says. "A large number of viewers actually get a false sense of security because so often the people who are used as participants in programmes have such extreme problems it allows everyday people to sit back and think, 'Thank God I'm not as bad as that. I don't need to do anything.'"

Denby was one of the experts who appeared two years ago on Channel 4's The Fit Farm, which featured 10 people trying to lose weight. "My feeling from that experience is that some of the participants can do very well from it, but for others it can be a quite dramatic and difficult experience."

He says those in the programme were chosen for their ability to "make good telly", which meant some were selected because they would find the process upsetting and cry on camera.

Experts can also be chosen more for their entertainment value than their qualifications, he says. "Usually the criterion is the person who can bully and humiliate rather than actually help."

Andrew Hill, a professor of medical psychology, refuses to appear on such shows. "These types of programmes are broadly entertainment and have little merit scientifically, clinically and personally, particularly for the viewers," says Professor Hill, a former chairman of the Association for the Study of Obesity.

"I would question whether they have a lot of merit for the participants. They reinforce stereotypes about overweight people andinvite the audience to laugh at them."

'Too Big to Walk?', Channel 4, tomorrow at 9pm

TV DIETERS: WHAT HAPPENED NEXT

You Are What You Eat

Lorna Slater, 50, a business development manager from Rushden, Northants

My colleagues put me forward. I was nearly 50 and 13st 7lb. The production company filled my cupboards with sweets and put a cheesecake in the fridge, which annoyed me. I was in tears because Gillian ripped me to bits. When she inspected my poo it was horrendous - she told me it was the worst she had ever had. I lost a stone and a half and felt fabulous, but I'd put it back on again within two or three months. I slipped back into bad habits.

You Are What You Eat

Kim MacDonald, 39, a waitress from Cambridge

I had to do something. I was more than 17 stone. It was very, very hard at first but I got into it and wanted to prove everyone wrong. Gillian made me cry, but not in a horrible way. She told the truth. People say that you're nice as you are - she told me that if I didn't lose weight I'd have a heart attack before I was 40. She gets behind why you eat. I lost three and a half stone and I've lost another 9lb since. I feel brilliant. It was the best thing I ever did.

Celebrity Fit Club

Russell Grant

I agreed to go on because I had a mini heart attack about two years ago and I needed to lose weight. I was 22st 11lb. I lost nearly four stone, and a couple of pounds since. I've kept it off because of the way they taught us how to eat. It was all very, very good advice. I have spent 40 years on television and it was one of the happiest, exciting, constructive and productive shows I've ever done. It didn't bother me that my weight was being used as entertainment.

Ian Wright's Unfit Kids

Jerome Trim, 15, from north London

I was picked to go on the show by my school. I just wanted to meet Ian because I'm an Arsenal fan, but when I got through I was really excited and wanted to prove that I could change. I wasn't happy and didn't like myself very much. Before the programme I just went on my PlayStation and watched films on the TV. The programme showed me that there were sports that I could enjoy, and I lost a stone. I feel so much better now. I go to the gym three times a week, and swimming, and I'm always outside with a ball playing football. Sport is fun. I didn't know that before. I like myself much better now.