It forms part of a wider campaign, which has been backed by public health experts and commentators, that says the reality TV show has hit a new low. Chief among concerns is that the show will feature children for the first time. The youngest contestant is a morbidly obese 15-year-old boy. The show's theme this year is the ''Next Generation'', as overweight parents team up with their kids to ''make a promise that allows you to change the future of your family''. The producers claim that this year, The Biggest Loser is ''not just a television event, but also a social movement that aims to break the vicious cycle of generational obesity''. But parents and health professionals aren't buying it. The Parents' Jury, an online network that promotes healthy eating and exercise for children, says the show is exploiting vulnerable kids for entertainment. The group has raised fears that if the young contestants - many of whom have been bullied - put weight back on, they will face further ridicule when they return to the real world. Eating Disorders Victoria has posted a statement on its website condemning the show and sent a letter asking the production company what screening for body-image disorders the contestants have undergone before appearing on the program.

Shine Australia has not responded to this letter, nor to Ms Graham's. Chief executive of Eating Disorders Victoria Jennifer Beveridge said the show's tactics were part of a ''moral panic'' over obesity that was fuelling an increase in body-image problems. ''We see people every day who are so scared of being obese, they will do anything not to be fat or overweight so they continue to reach for that ideal, which is that if they lose weight they will feel good about themselves, they will look better. It's that voice in the head that's saying, you're not good enough,'' Ms Beveridge said. ''The bottom line is fast diets don't work. People engage in them because they want to see a quick change and if you've got somebody yelling at you, the fear and shame of failing is the motivating force in the situation rather than the positive strengths of building resilience from within.'' But one of the show's personal trainers, Shannan Ponton, defended the program and said that as a society we need to ''harden up''. He said the trainers' tactics were designed to get the most out of people who had failed to lose weight any other way.

''We definitely do push them to the limit, but that's to get a desired result. If it upsets people at home, I can put their minds at rest because the contestants, once they have started their journey, will never look back. They've never been fitter, happier or healthier.'' Dr Leon Massage, a GP and weight-loss and nutrition spokesman for the Australian Medical Association, has treated former Biggest Loser contestants who regained weight after leaving the show, finding its regime was unsustainable on the outside. He said while contestants seemed to lose large amounts of weight each week, former participants had told him the weigh-ins were often not filmed weekly. ''It sets up this dangerous and unrealistic expectation among the general public that this sort of weight loss is normal,'' Dr Massage said. Mr Ponton conceded that on previous seasons of the show, ''weekly'' weigh-ins were sometimes recorded nine days apart. But he insisted the weight loss was achievable. The show has come under fire in previous seasons for pushing contestants to exercise until they vomit, and for allowing a 214-kilogram man to collapse during training for a marathon.

A spokesman for Channel Ten said: ''All contestants work with highly qualified and professional trainers, nutritionists and psychologists. We are not, repeat not, in the business of shaming contestants. The Biggest Loser has a long history of helping people … address their weight issues and helping them lead healthier lives.''