he show titles of last week's three episodes of Ricki Lake were "I Hate Who You Date", "I Refuse To Be Used" and "Mum - Grow Up and Act Your Age". For all the kamikaze frankness of the festival of dysfunction she presides over, the Hairspray star turned talk show empress is the first person in the history of these interviews to object to having her picture taken while she chats.

"How long is he going to be doing this?" Lake, 27, demands, diminutive but stern, as the photographer struggles to blend into the hotel wallpaper. Her head snaps into a reflex rictus whenever she feels the lens upon her: "I'm trying to concentrate and he's, like, moving around."

Already an institution in its fourth series, Ricki Lake's youthful take on the classic US studio bloodbath format often outscores Oprah - the mother of all talk shows - in the British ratings. How does she feel that the unique means of communication, talk show language, differs from standard conversation? "There always seems to be some stupid rhyme or slogan. We try to be as cheesy as possible." She pauses: "Is cheesy a word here?" Yes. "Good. My favourite title of all time is 'You Have Naked Pictures of Me and I Want Them Back Now'."

Does Lake ever find it a frightening show to present - for instance when the audience is baying for blood and a crazy woman in a polyester trouser-suit, which gives off enough static electricity to run the Blackpool illuminations, is complaining of being beaten up by her teenage daughter? "I can't say I'm ever scared ... I'm glad to say that no one has ever hurt themselves - or anybody else - on our show." There does seem to be a lot of anger in the studio sometimes, though. "A lot of anger," Lake concurs wistfully, "and a lot of sadness."

At this point Ricki Lake's executive producer, Gail Sternberg - a scary, overseeing presence hunched in a large armchair in the corner of the room like a hungry bird of prey - opts to swoop. "Isn't it interesting that the British reaction to people expressing themselves emotionally is that it's frightening?" she demands. "Am-ericans don't view it that way."

But wouldn't some of the issues raised on the show - "Today My Mum Confronts the Guy I Lost My Virginity To" springs to mind - be better addressed privately? Lake looks concerned. "Certainly people do sometimes talk about intimate things which I wouldn't necessarily talk about for the first time on TV, but I think regardless of where they do it, it's better to get this stuff out than slip it under the rug."

Lake is not afraid to make her own contribution to an atmosphere of full and frank discussion. On her recent appearance on the Gaby Roslin Show, it took only the briefest application of Gaby's velveteen inquisitorial thumbscrews to elicit the revelation that when she first met her husband- to-be - illustrator Rob Sussman - at a Hallowe'en party a couple of years back, Lake was "naked within two hours". "I guess I can share this" - Lake looks to Gail for reassurance. There's more? "I'd been with someone else the night before, so when I told all my friends the next day 'I met this amazing guy and I want to marry him' they were like 'Dean?' And I said 'No, you know - Rob' - and that is so not me. I mean, I was such a prude in high school I was a virgin till I was [inconclusive hand gesture] so old."

Ricki Lake comes from the sort of settled family background that might be the envy of many of her guests. Raised in suburban Westchester county, half an hour from New York city, Lake's grandmother instilled a love of the performing arts in her by taking her to plays and operas and ballet in the city every weekend. Her father, a pharmacist, maintains a "Ricki shrine" of articles and photographs, dating back to well before she secured the lead role in John Waters's hit 1988 film Hairspray during her freshman year at college.

Part of what made the Ricki Lake of this period such an appealing figure was her total lack of inhibition about what Waters's script graciously termed her "heftiness". "I was the fat girl who got the part because I was fat, so it was something I was completely comfortable with: I only started to care when it stopped working for me." After making six films back to back and securing a major role in a trashy TV show called China Beach, things started to go wrong for Lake. At the age of 20 she found herself "in a horrible relationship with a really abusive guy and weighing 260 pounds".

In shedding half her body weight to come back from the dead as a global microphone goddess (her show is as big in Thailand, New Zealand and Sweden as it is back home in America) Lake has acquired some fairly formidable armour plating. A small disturbance outside the interview room inspires a reaction worthy of Alexis Colby: "I just got back from lunch and it's like distraction, distraction, distraction." Gail gets up to put an end to it, and Ricki is almost shame-faced: "I'm sure they're working, I don't want to make them stop."

"One of the things that we've discussed a lot and I know Ricki feels very strongly about," Gail butts in supportively, "is that talk shows have become the community of the Nineties." Beneath the bland, mashed potato surface of this generalisation there lurks a piquant cheesy sauce of truth. One of the most affecting things about the people who appear on Ricki Lake (or Oprah or Jenny Jones or Montell Williams) is that they might actually be right - this might be the best chance they've got of affirmation or romance or psychiatric help. The other uncomfortable reality is that the talk show arena - gladiatorial as it is - seems to be the nearest thing American society currently has to offer to democracy in action.

"The audience gives a lot of good advice," Lake observes. "You know they don't live by what they're saying, but they like to say it." In what way don't they live by it? "They're always so politically correct - you can see their noses growing as they speak because they're just, like, so full of it." But surely the point of the show is that one person's say is as good as anybody else's? "Exactly: we have gay people on, we have all minorities on, and we treat them like every other guest. We have people who are, whatever you call it, 'trailer park trash' and I treat them with the same respect with which I would treat the Queen."

This might explain why Ricki Lake has attracted so much condemnation from right-wing American politicians and media commentators. "I think they're just pointing a finger at the easiest target they can see," Lake suggests. "They're not looking at their own responsibilities: the provision of education and health services in America are in a despicable condition and our show reflects these problems. These are much bigger issues than whether someone should be revealing that they have a secret crush on their schoolteacher."

"The average income for a family of four in the US is $17,000 (pounds 11,300) a year," Gail points out. "The people we have on our show are most of America. They're people who don't have access to psychiatrists and health care - and that's what people like William Bennett [the Republican moral guardian who called Ricki Lake "cheap, demeaning and immoral"] can't stand about it.

"TV shows like Leave It To Beaver, The Brady Bunch and The Cosby Show have always tended to reflect a very idealised view of American family life, but talk shows are the one place you get real people."

In November 1994, Ricki Lake felt the fetid breath of the American fourth estate hot upon her own neck after she and her husband were jailed for 25 hours for their part in an animal rights protest (trespassing in the office of a fur-using fashion designer). "I just wanted to speak out about something and then the media started attacking me for wearing leather," Lake complains. "I mean, I was speaking out about fur and only fur, I don't have all the answers." Is she a vegetarian? "I go back and forth; because I'm anaemic, I have health problems where I need to eat meat sometimes ... Right now I'm a strict vegetarian - I eat only fish." But isn't that like being a strict teetotaller who drinks only lager? "Morally, I would love to never eat anything that has eyes." Except potatoes. Ricki laughs: "Yeah, right."

If it hadn't been for her weight loss, the Ricki Lake story would have been worthy of her mentor John Waters ("I remember him and Divine teaching me how to walk in high heels," Lake remembers fondly, "That was really fun.") Waters' films always seem to be about people expressing themselves by being different, so does he think Lake is the enemy now? "He's really shocked. First of all he never thought I would lose so much weight. He was always on at me after Divine died - because his obesity certainly had something to do with him dying at such an early age - saying 'I don't want what happened to Divine to happen to you.' Second of all, he can't believe I host a talk show and he's been on as a guest."

8 'Ricki Lake' continues, Channel 4, 5pm Tues-Thurs. 'Adult Ricki' starts late night Thursdays in July. Sample show title: "I Share My Husband with My Sister".