Hey ladies, here's a great diet tip: turn on the television and watch any of the cautionary-tale programmes breaking out about the morbidly obese.

Initially, I thought they'd be of the freak-of-the-week genre that really puts you off the Haagen-Dazs. Actually, they did make me think I didn't need another bag of Cheezels - but not because I was grossed out. Rather, because these stories show how easy it is for comfort eating to lead to obesity.

Tonight's Fat Doctor episode on Prime is a sensitively made English documentary that recognises the sadness that lies behind most really big people. It tells the story of Lubna who weighs 159kg and whose unhealthy relationship with food has ruined her life. She was a normal size until her early 20s when she moved in to look after her sick parents. After they both died, she says food was the only thing that helped her through the pain. There is also the story of Sarah, who lost 57kg after gastric surgery.

TV3's Wednesday documentary, Too Fat For 15, is the true story of Brit teenager Georgia who became hugely overweight after her father died. Georgia is too young for gastric surgery so is sent to a special weight-loss boarding school in the US.

She is a remarkably articulate young woman. "I have to do this. I could be dead next year if I don't take this opportunity."

Her boarding school programme includes diet and exercise but also therapy and counselling to tackle the reasons why food has become such a problem.

Meanwhile, The Fattest Man in Britain, also on TV One tonight, is not a true story but a quirky British drama about a housebound, grotesquely obese man named Georgie (Timothy Spall) .

It looked like it might be in grossly bad taste, since it opens with Georgie singing Turning Japanese, complete with slitty-eye gestures, for a group of Asian tourists. But it turns out to be a heartwarming story about how Georgie struggles out of his chair after meeting Amy, a community service worker who is the first person to care for his welfare without having a vested interest in keeping him big.

The funny thing is, having watched all three programmes, I was struck by how similar all the stories were. Also, how lovely all the overly big people were. They all seemed to be very sensitive people who had turned to food to try to soothe their emotional pain. There has been so much talk about the obesity epidemic it is easy to zone out or to think the issue is all about food. It's not; it's about the ways people cope with painful feelings. That is so sad it takes your appetite away.

The Fattest Man In Britain plays on TV One tonight at 8.30 and Fat Doctor is on Prime at 10.35pm. Too Fat For 15 repeats on TV3 Wednesday at 9.30pm.