The comedian Bob Mortimer once described Matt Lucas as “the angriest man I have ever met”. Lucas was 18 when Mortimer said it and he’s 35 now; the quote has been hanging around his neck for a long time, so maybe it’s time to take it off. “Teenagers can take themselves very seriously; you spend too much time on your own, you start to mythologise yourself. You wear your perceived nonconformity on your sleeve.”

Lucas didn’t seem angry when I met him. Not at all. He gets upset and depressed from time to time, he says, like many people. But in our interview he was amusing, polite, most of all thoughtful. He seemed like a man who has put in a lot of work on himself, and the work has paid off. The tears of a clown may well have flowed 15 or 10 years ago; I’m not sure they do any longer.

We meet in a photography studio in North London. He is here to publicise his new BBC series, Kröd Mändoon and the Flaming Sword of Fire, a “Blackadder meets Red Dwarf kind of thing” in which he plays an “Alan Rickman-esque Sheriff of Nottingham psychotic baddie. I got the script and it really made me laugh. I auditioned for it and got the role. It was a giggle.”

He’s been followed to the studio by paparazzi, “but it would be churlish to aspire to be on television for many years and then to be on television and moan”. The media have, in any case, “cottoned on to the fact that a picture of me as Vicky Pollard is a lot more interesting than a picture of me walking my dog [Milo, two, chocolate Labrador]. Also, for the majority of the time that I’ve been famous, I’ve been in a relationship, and to be in a monogamous gay relationship is not as interesting as being, say, straight and single.”

Like his Little Britain partner, David Walliams, for instance? “Like David or Russell Brand or all those people. And they would be considered sexier and more attractive than me. I don’t crave more attention than I get. I will always, like the vast majority of people, look at a photo of myself and wince or cringe. I’ll always have that, but I think it’s quite natural.”

When we met some months ago, Lucas was single again after his long relationship with Kevin McGee ended in summer 2008. “I was with Kevin for almost six years, from August 2002.” The two men had had a civil partnership in 2006, finally dissolved in January this year. Lucas and McGee have both a gentlemen’s and a legal agreement not to discuss their relationship. “We turned down offers to photograph our ceremony. Kevin didn’t ask to be in the public eye, I still feel very protective towards him,” says Lucas. “I’m not in another relationship,” he said at our interview, “and it’s not something that I am looking for.”

Months later, however, during a telephone update, that situation has changed. “There is someone I like at the moment,” he says, “who likes me. It’s very early days and it came as a surprise to me. That’s all I’m going to say; I don’t want to jinx anything.”

The other big change between the initial interview and the phone follow-up is that Lucas has been on a serious, and so far successful, diet. “I was 106 kilos [getting on for 17 stone] when we met. I’m 90 kilos now.” This equates, he says, to ten inches around his stomach. He wants to get to 70-75 kilos (about 11 and a half stone) which, for a man of 5ft 6½in (“I really treasure that half”), “may still be a bit tubby, but I don’t mind”.

Is he feeling more attractive? “A little, maybe. But then, almost everybody I’ve ever dated, I’ve felt they were really handsome and they’ve felt the opposite. Beauty is in the eye of the beholder.”

For the photo shoot, Lucas is wearing a green corduroy suit and a bright red shirt. You’d think maybe he was a classic look-at-me extrovert, but he isn’t at all. Instead, this chap who dressed up in a Babygro when he was first on TV at the tender age of 18 in Shooting Stars, or strutted around in spandex as Daffyd the only gay in the village, is self-effacing to the point of shyness.

We sit in the café at the photography studio. He has a hot chocolate and a cookie (this is pre-diet). He speaks quietly, doesn’t draw attention to himself. His humour is the opposite of slapstick: so deadpan it takes a moment for the gag to register. When I ask him if he weighs himself, for instance, he says, “Yeah, I do, and then I get peckish and eat the scales.”

I say I’m someone whose weight also fluctuates dramatically. “Whereas I’m lucky I can eat and eat and eat and not put on an ounce.”

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010