The 45-year-old star of the Bridget Jones films puts her new looks down to changes in her lifestyle, dismissing rumours about cosmetic surgery as silly. "I'm glad folks think I look different," she said. "I'm living a different, happy, more fulfilling life, and I'm thrilled that perhaps it shows."
Before and after: Renee Zellweger in 2000 and in late 2012. Photos / Getty Images
Still, the pictures unleashed a media storm, with various commentators blaming an appalling misogyny that forces beautiful actresses such as Zellweger to embark on surgery the moment they fear their looks start to fade.
Away from Hollywood, the issue was again highlighted by the news yesterday that a 24-year-old British woman had died undergoing liposuction at a clinic in Thailand.
So, what is it like for the loved ones of people who decide to drastically change their appearance, with potentially life-threatening risks? And was my reaction to my mother's new face typical?
"When someone you love makes themselves unrecognisable through surgery, it can be very disconcerting," says Frank Furedi, author and professor of sociology at the University of Kent. "You have to renegotiate your relationship with them and it's not always possible to do this successfully. Changing your appearance changes something very fundamental in the way people know you, and sometimes loved ones never acclimatise."
My mother's botched facelift in February 2004 unleashed six months of shock in our family. We were appalled that a supposedly routine procedure, carried out by a leading London surgeon at great expense, could have gone so wrong. Her skin had been pulled back too much on one side, making her face look uneven, and she had scarring and a lump on her nose. I was 25, and seeing her changed appearance was profoundly upsetting. Only her sad, frightened eyes were familiar.
I held her hand at her bedside as she described the terrible pain she was in, and how fearful she was that she was never going to look like herself again. Whether or not she should go back and have it redone, with all of the risks, or just live with it became the only subject our family talked about for months.
Figures from the British Association of Aesthetic Plastic Surgeons show that more than 50,000 cosmetic surgery procedures were carried out in the UK last year, a 17 per cent rise on 2012. Consumer confidence in the sector seems to be at an all-time high, with breast augmentation rising 13 per cent, despite fears about some implants.
Karl Burkitt, 54, was concerned when his wife Penelope, 47, who works in the beauty industry, told him she wanted cosmetic surgery. "I didn't think it was necessary," says Karl, who runs a consultancy business and lives in Cheltenham. Yet despite his reservations, he accompanied Penelope to a clinic in Istanbul earlier this year where she had an endoscopic facelift, an upper and lower eyelid tuck and nose-tip refinement in surgery that took 10-and-a-half hours.
"She awoke drugged and covered in bandages with drains on either side of her head taking the blood away," says Karl. "It was gory and very upsetting - horrific, in fact. I couldn't understand why she had put herself - and me - through it.
"When the bandages came off, Penelope looked completely different from the woman I fell in love with. Her skin was taut and stretched, her nose was much smaller, even her eyes looked different. I'm still not clear why she wanted to have it done and that's something that does play on my mind. I don't think she needed to do it - but she feels happier with the way she looks now and I suppose that's what is important."
Jennifer Townsend, 33, a solicitor from Esher, Surrey, also found it hard to come to terms with her mother's dramatic new look after she had a facelift, eyelift and nose job five years ago. "She had been unhappy with her appearance for a long time and decided, at 62, to do something about it," says Jennifer. "She was delighted with her new look, but my father and I found it very difficult to get used to it. She looked radically different, as if she had taken over the face of a stranger.
"She and my father went through a rocky patch for months afterwards. He said the whole experience was very unnerving, like waking up one morning and finding yourself married to a completely different person. My mother also found it upsetting that we couldn't just be pleased for her. What she didn't understand was that we had both thought she was perfect as she was."
Furedi says adapting to a loved one's new face can be "impossibly distracting if, all the time you're talking to someone, you are comparing and contrasting the new face to the one you knew and loved".
Recent research suggests mothers who have had cosmetic surgery have problems bonding with their newborns because their faces are not moving in the right direction. Those who have Botox can also damage their babies' ability to interpret the emotions of others, which they learn from their mothers' expressions.
Others whose relatives have gone under the knife report feeling angry and hurt that a person they love is putting their health at risk - and potentially the happiness of their family - for a vanity procedure.
The American rapper Kanye West is said to have banned his wife, the TV reality star Kim Kardashian, from undergoing cosmetic surgery after his mother, Donda, died on the operating table in 2007 during a breast-reduction and liposuction procedure. Meanwhile, Joan Rivers's daughter Melissa pleaded with her late mother, who is believed to have had 739 procedures, to stop. "I started to think the risk outweighs the reward and I wanted my mom to know how I felt," she said in 2012.
The American author Candy Schulman recalls feeling fearful and angry when, aged 16 in 1969, she went to visit her mother in hospital after her facelift. "I felt as frightened as if she'd survived a near-fatal car crash and suffered traumatic brain injury... and angry that my parents hadn't warned or prepared me. Decades later, whenever anyone mentioned how 'young' my mother looked, I was reminded about how upset I'd felt that day, as if it had happened yesterday."
As for my mother, after those traumatic first six months, she eventually decided to have her facelift redone. "I went from being confident about my appearance to being horrified by it," she says now. "My lowest point was when I went to see another surgeon and he said, 'I'm not sure I can do it'."
Her second operation was, however, a success and today she looks exactly like herself again, just younger and fresher. Best of all, she is back to her ebullient self and, despite her horrendous experience, remains adamant that rather than being instruments of misogyny, facelifts give older women like her a new lease of life.
"The only slight drawback to looking 10 years younger than your contemporaries is that you can encounter a little jealousy," she says. "Especially if, like me, you're not mixing in Hollywood circles, but considerably less sparkly ones in suburban England."