Serena Williams arrived in London on Thursday for her much-hyped return to professional tennis after a four-year hiatus.

Her entourage, at just 12, is now half of what it was during her glory days as a 23-time singles Grand Slam champion.

Williams is half her size as well.

Since giving birth in August 2023, a year after announcing her retirement, Williams has lost 34lb. She has posted many, many photos of her abs on social media: a post showing her body alongside that of her on court in her heyday is shocking, as though she has been boiled in a hot wash.

That glorious backside is no longer bootylicious, merely deflated. As one online commentator puts it: 'Is that what her husband wants? ... She looked good thick.'

Serena's weight loss has been well-documented and just as well-marketed.

An advertisement during the Super Bowl in February for the weight-loss drug company Ro, in which her husband, deep-pocketed Reddit founder Alexis Ohanian, is an investor, championed both facts in front of millions.

It's handy that weight loss drugs are not banned in tennis under doping rules. It's even handier that the US is one of only two countries to allow the promotion of prescription drugs (New Zealand is the other).

And why on earth did Serena rock up at the Met Gala in Marc Jacobs last month to stake a place among skinny idiots who think making the shape of a teapot is an achievement?

Serena, 44, is in the UK to play doubles at the HSBC Championship at the Queen's Club in West London, which many tennis insiders are already calling a warm-up for Wimbledon at the end of June.

Whether she winds up back at the Grand Slam, one thing is clear: Williams' appearance in London is a master-class in product placement – and the product is her.

Why Serena, oh why?

You are already worth hundreds of millions of dollars and your husband at least a hundred more. You and your sister blazed trails now inhabited by younger players of color, like Naomi Osaka and Taylor Townsend, another super-curvy athlete who won the doubles at the French Open on Sunday.

You've weathered intense criticism and even on-court outbursts with your integrity and legacy intact. Why cheapen it now by turning yourself into a walking billboard for pharm-assisted weight loss?

Williams clearly, if over-optimistically, wants to win; and if she does carry a match or two, what greater promotion could there be for a drug that tends to leave many of its users hollow-eyed, arms resembling violin bows, with thinning hair, loss of libido, often nauseous and empty of pocket?

The problem, beyond the tackiness of appearing to shill for her husband's side hustle, is this: Serena has always been, like it or not, the fierce, uncompromising poster girl for women who do not want to look like stick insects. For whom being tiny, sweet, uncomplaining with a jaunty blonde ponytail holds no truck.

Her body has been her meal ticket, the best in the world.

She ignored or more likely withstood the criticism of her shape – she and older sister Venus endured negative comments even on court, notably from Swiss player Martina Hingis - who in 2004 compared her style to 'playing a steamroller' that she lacked subtlety and finesse - to reign supreme. Serena even played while eight weeks pregnant during the 2017 Australian Open.

Now, though, it seems she has succumbed to the Kate Moss mantra: 'Nothing tastes as good as skinny feels.' 

Her many fans say that she has a history of diabetes in her family. That her joints, battered by decades on court, could do with a little less flesh on them. 

But if even one of the world's greatest athletes believes her body isn't good enough, then what hope is there for the rest of us?

Serena seems blind to how wonderful she was because athletes are fragile, self-doubting: you only have to look to Aryna Sabalenka, the world No 1 in women's singles, punishing herself when crashing out of the French Open last week.

Serena back on Centre Court reminds me of Madonna, 67, gyrating in her undies above Times Square a few days ago. But Williams should - with a loving family, wealth and an unimpeachable legacy - be able to sit back and bask in the glory. Why are you doing it again?

It's undignified, and the worst possible example for girls: that they will have to be toned, waxed, perfect and match-ready until they're almost 70. 

Men are allowed to run to seed, kick back with their spiraling eyebrows and balloon bellies. Does Beckham wish he was brighter at 51? Did Maradona at barely 5ft5in yearn to be taller? No! But for women, the honing and harvesting always winds up front and center.

If Serena crashes out at the Queen's Club, despite Canadian teenager Victoria Mboko as her doubles partner, her extraordinary legacy will be in the trash.

Overweight or even merely physically insecure young women have looked to Serena Williams as a lifeline. No one wants to be unhealthy but surely being at the top of a highly competitive, physically demanding sport is proof thinness is not the ideal standard of beauty and certainly not the pinnacle of health.

I've campaigned for 25 years for more diverse body shapes in the media, only to be thwarted by huge industries (namely fashion and beauty) who want to sell you stuff; if you're happy in your own skin, of course you buy less.

When I photographed Renee Zellweger for the cover of Marie Claire on the eve of the first Bridget Jones film a quarter-century ago, I was dismayed when she turned up at the studio too skeletal to fit in any of the clothes, ribs showing, collarbones jutting: even she despised the full silhouette of a character that made her career.

Today? We've taken a huge step backwards: one size must fit all, no matter the cost. Women now believe a drug is the only thing that can save them.

Serena's transformation and desperation feels like a betrayal. As though Dame Judi Dench emerged having had a face lift, eager to play Juliet.

Call me evil, but I hope Williams crashes out (as she seemingly cashes in) during straight sets this week, devastated as I am to read this comment on Reddit, which her husband founded back in 2005, of all deeply ironic forums...

'As a young female athlete who looked up to Serena in regard to her body confidence ... I am so sad to think that the next generation of young women won't be able to feel the relief that comes with hearing: "Look at Serena Williams, she's the best in the world, and her body is just like yours."'