SHE is one of the country's all-time most successful sportswomen, but a cursory trawl on Google before meeting Rebecca Adlington makes for disheartening reading.

Rather than celebrate her many achievements, which include being a double Olympic champion, the internet yields a litany of cruel taunts from online trolls who have honed in on her appearance, variously labelling the former swimmer as "ugly", criticising her "shark fin nose" and saying she looks like a "whale" and "dolphin".

Unsurprisingly, Adlington, 25, has a lot to say on the topic of body image, not least when it comes to imparting a positive message to young girls and women. In person, she is far from the caricature the aptly named trolls would have us believe. Strikingly pretty with huge blue eyes, a sheet of blonde hair and disarmingly warm smile, for the record there is no resemblance whatsoever to the raft of ocean-dwelling creatures to which Adlington is regularly unfavourably compared.

One of the first things that strikes you is her textbook girl-next-door demeanour. You could easily picture Adlington having a laugh at Take Me Out on a Saturday night while sharing a bottle of wine and a family-sized bag of Maltesers with a gaggle of mates. She possesses a sunny disposition and lack of bitterness which belie the onslaught of disparaging comments.

By her own admission, Adlington has become adept at dealing with the soul-sapping remarks thrown like emotional grenades from the anonymity of a computer keyboard. She was first catapulted into the public eye after winning two gold medals at the 2008 Olympic Games in Beijing. Four years later that interest intensified when she competed at London 2012 claiming double bronze.

While she concedes that once you've read something, you can't unread it, especially when it plays on your insecurities, Adlington has learned to box clever when it comes to preventing negative comments from affecting her. "I'm definitely getting better at stopping it encroaching," she says. "Especially things like Twitter that are on your mobile phone, I think we all have a habit of letting it creep into life all the time. Before you go to bed or when you wake up in the morning, you check your phone.

"So I've been a bit more: 'You know what? This is my family home. This is where I live with my boyfriend. Why am I letting it creep in to that side of things?' When I'm at home that is my area to relax, be myself and to feel free - and rightly so. You need to have those boundaries and I've definitely learned that."

One of the most high-profile figures to pass their critical judgment on her appearance is Scottish comedian Frankie Boyle who, in 2008, said on BBC panel show Mock The Week: "The thing that nobody really said about Rebecca Adlington is that she looks pretty weird. She looks like someone who's looking at themselves in the back of a spoon."

It earned a reprimand from the BBC Trust who branded it "humiliating" and "offensive" but two years ago, Boyle reprised his caustic attack by posting on Twitter: "I worry that Rebecca Adlington will have an unfair advantage in the swimming by possessing a dolphin's face."

I'm curious as to whether Adlington has ever met Boyle and called him out on his remarks. Her response is sanguine. "He's a comedian," she says. "I do understand comedians highlight certain things and they take the p***. None of us can say we have never laughed or found that humour funny. I don't personally like his humour, I just don't get it. I prefer Jason Manford, Peter Kay or Michael McIntyre where their humour is more story-based about their lives.

"I've never met [Boyle] but I know he does this to loads of people. I'm not the first and I definitely won't be the last. I don't think he picks people out to be personal. It's what he finds funny, I guess."

There have been rumours that Adlington underwent a cosmetic procedure earlier this year to have a bump removed from her nose. The contours of her profile certainly look smoother than in older photographs, although it's something she refuses to confirm or deny. "I don't really want to talk about surgery, thank you," she says, politely but firmly when the topic is raised. It's the only time during our conversation that I sense anything remotely resembling raised hackles.

The youngest of three daughters, Adlington grew up in Mansfield, Nottinghamshire. While she remains Britain's most successful ever swimmer - an Olympic, world and European gold medallist as well as reigning double Commonwealth Games champion - when it came to calling time on her sporting career, she was more than ready to walk away.

While many former athletes struggle to fill the void - fellow swimming legend Adrian Moorhouse said recently it took him "about two Olympics" to stop wishing he was taking part - Adlington had no such misgivings. "It took me a day," she says. "I just was so ready. There is not 1% of me that wishes I was in the pool. I have no regrets. I think it has to be your decision and I'm lucky it was 100% me saying: 'I'm done.'

"I just didn't enjoy the racing any more. I'm not competitive. I guess that's why I don't miss the competitive element of it one bit. I much preferred the training, which in swimming is 99% of it, so I chose the right sport. If anything I miss the training."

Since retiring in February last year, she has launched her eponymous nationwide learn-to-swim scheme, Becky Adlington's Swim Stars. In addition, Adlington is an official ambassador for Glasgow 2014 and will be in the thick of the action at Tollcross International Swimming Centre - albeit it firmly on dry land - fronting BBC's coverage of the Commonwealth Games.

"I've never to this day got nervous about TV, it just doesn't faze me," she says. "I think, 'Just be yourself'. If I got nervous, I'd probably stumble on my words. I prefer to be natural and let it flow. I know the sport inside and out, I know everything there is to know about swimming and that's what I'm going to be talking about.

"I've been lucky enough to go to a Commonwealth Games so I think you've got to talk from your own experiences."

Tory MP Helen Grant, the UK Minister for Sport, Tourism & Equalities, came under fire in February for suggesting British women should be encouraged to take up "feminine" sports such as cheerleading and ballet, activities, she said, that would leave them looking "absolutely radiant". I'm keen to hear Adlington's thoughts on those comments.

"It's each to their own," she says. "That's like saying the boys should stick to rugby because that's more manly. Or that a working-class person can't play polo or tennis. That is ridiculous. Sport is for everyone and that's what is so great about it. No matter who you are, what your background or culture, whether you are disabled or not, that is what sport embodies: it gives everyone the same opportunity.

"My parents tried me with ballet when I was younger and I hated it," she adds. "I love swimming but I would still consider myself feminine. Obviously I'm not" - she adopts a cut-glass accent - "'afternoon tea, darling', prim and proper, but I love all that girly stuff like painting my nails, putting make-up on and getting dressed up.

"That was what was great about London 2012. I loved seeing Jess Ennis on the front of magazines looking beautiful, stunning and promoting a healthy body image. It showed if you have muscles that is amazing. It's what has given her an Olympic medal, so why not show that off?

"It's much better than showing someone who has been airbrushed to the max, that is not natural. I would much rather see Jess than really airbrushed models. For me, I think we need to show that off more."

Adlington has spoken in the past about her own struggles with body image, not least during her time on ITV reality show I'm A Celebrity ... Get Me Out Of Here, when there were countless media comparisons with her fellow contestant Amy Willerton, the 2013 Miss Universe Great Britain.

According to Adlington, the show's producers edited out a long discussion on the topic of body image, something which disappointed her greatly. "We all said - and this was the thing they edited out - that there needs to be a change," she says. "I've never sat down with my friends and said: 'This is what I'm insecure about'. We joke and mess around, but I would never seriously say: 'This is what bothers me'. We need to get it out there, be more open and honest. That is what we said, but obviously they [the producers] made it out to be more of a me versus Amy thing rather than a positive message."

But what did prove eye-opening, says Adlington, was hearing Willerton alongside some of the show's male celebrities admitting that they too had been victims of online trolls. "Hearing Amy and even the boys saying: 'I get people sending me nasty messages on Twitter all the time', kind of shocked me because I've never spoken to anyone else who has been through it as well," she says. "It was helpful because I realised how powerful it is to speak up and talk to someone about it."

She hopes sharing her own experiences will help drive home that message to young girls and women. "Being a woman in sport, your body is your tool," she says. "We look at our opponents and think: 'Wow, she's in good shape', we don't think: 'Oh, she has cellulite, she has big boobs' - or whatever it is. It's about our strength and power. These are our tools.

"It's interesting coming out of that world and being a normal 25-year-old girl, which I am now, but my body is still moulded on that swimmer. For me, it's something people feel they want to comment on. I just don't get that side of it. If someone says: 'Oh, she's got a little bit of cellulite' or 'look at that roll [of skin]'. Everyone has that. Every single women. It's not news that someone has a roll. Even the skinniest person, if you sat in the wrong position, it [your skin] will roll over. I don't see why things are so highlighted around a woman's weight and a man doesn't really get the same abuse.

"If a man doesn't have a shave it's 'sexy stubble'. What's wrong with a woman having a bit of cellulite, then? It's natural. I don't get highlighting it when it can't be helped."

Adlington experienced her own body going through a stark transformation when she retired from sport, not least getting used to no longer needing 3500-4000 calories a day to fuel training. "I definitely put on weight after I finished swimming," she says. "A lot of athletes go through that period where your appetite is still the same but you aren't exercising. That is something I had to adapt to but at the same time I think it just naturally happened.

"It probably took me a good year to make all the changes. What happened is I had muscle, then started to have a bit of fat. The ratio of muscle to fat was kind of flipping on its head. It was about losing all that muscle definition then losing the fat. My body structure is still the same. I'm 5ft 11in. I'm big built and still have big shoulders. That's never going to change because the muscles and the bone have developed that way. I'm always going to look like I've done sport. I'm not as toned, my body doesn't have the muscle it did, but you get used to that."

After covering the Commonwealth Games, Adlington will concentrate on the finishing touches of her wedding plans with fiance and fellow swimmer Harry Needs. The couple are due marry in Manchester next month and she jokes that viewers shouldn't be surprised to see her hastily writing up place cards between commentary sessions. "It's one of those things that seems to be never-ending," she laughs. "It's been hectic but we have all the big stuff done - it's now the little details which I'm not very good at."

Beyond that, Adlington doesn't rule out dipping a toe further into the world of television. She's already done a stint on Loose Women and quite fancies the chance to showcase her aspiring culinary skills on The Great British Bake Off. "I do love baking but I'm crap at it," she laughs. "I'm more about taste than how it looks.

"One thing I make a lot is banana bread because it's so easy, you can wrap it up and it lasts a few days. It's not something that has cream on it where you worry it's going to melt if you take it out for the day - it's practical.

"I'm very much a traditional type of eater. I love casseroles, chicken stew, lasagne and I'm the same with cakes. I like a Victoria sandwich, your traditional and hearty food. I'd take pub food over a Michelin-starred restaurant any day."

Rebecca Adlington is part of the line up for the BBC's coverage of the 2014 Commonwealth Games in Glasgow, live across the BBC on TV, Radio 5 live, online and mobile from Thursday