Hands up everyone who knows a diet bore.
You know, the one who hasn't eaten carbs since 2002, always asks for her dressing on the side and only drinks clear spirits.
In my experience, just 15 minutes of concentrated diet talk is enough to drive the average woman to distraction (and Dairy Milk), so why do we have such an insatiable appetite for tabloid stories about celebrities and their weight battles?
Last week, it was Kerry Katona's turn again.
Despite the fact that she doesn't look remotely overweight, Kerry is rumoured to have gained a stone after tucking into curries, crisps and chocolate since being voted off Dancing on Ice.
Give it a month and no doubt she'll be making headlines for her 'great new shape', and a few weeks after that we'll hear how her 'friends' fear she's 'too thin'. And then the whole fat/thin cycle will begin again.
You'd have thought that the only person who would be interested in Kerry Katona's weight would be Kerry Katona.
But no.
Us Brits have become avid Celebrity Weight Watchers. Keeping tabs on the fluctuating weight of the stars has become a national sport – but unfortunately there aren't really any winners, just a succession of 'biggest losers'.
While it's true that a dramatic weight loss story can be inspirational, these are few and far between.
And even when a celebrity does manage to lose a significant amount of weight over a sensible amount of time, we can't quite bring ourselves to feel happy for them.
It's taken Fern Britton three years to lose five stone and drop from a size 22 to a 12 – but she's been accused of 'cheating' because she had a gastric band fitted, even though it still must have taken considerable effort and commitment to overhaul her eating habits and get fit.
When Jennifer Hudson stepped onto the red carpet at this year's Oscar's ceremony, rather than focusing on how stunning she looked in her red Versace gown, critics were quick to say that she's taken her weight loss too far.
Jennifer, who has dropped five dress sizes since 2009 and is now a slinky size 10, has been following the Weight Watchers plan and works out for 25 minutes five days a week – which sounds admirable, not excessive. She's spoken about how happy she is with her new body, and she's right to be – she looks great. So it must sting to be slagged off for being too thin – especially when she's just one unflattering paparazzi shot away from 'Jennifer's Shock Weight Gain' headlines.
Even the teeny weenies like Cheryl Cole aren't spared the scrutiny of the Celebrity Weight Watchers. Although she's usually scolded for being too thin, last month she was papped looked 'fuller faced' – and all women know that's code for 'fat faced', right?
Of course Cheryl, whose 'fat jeans' are probably a size six at most, looked nothing of the sort – but that doesn't stop us lapping it up.
Given that Britain is the 'fat capital' of Europe and around half of British adults are overweight, it's no surprise that we're obsessed with weight – but surely it would be more sensible to focus on our own dress size, not everyone else's.
And maybe if we could face up to the fact that we all have fat days and thin days, admit that fad diets don't work and accept that it takes time and effort to stay in shape, we'd stop scrutinising celebrity bodies.
And if we could do that, I'd hazard a guess that we'd feel much more confident about our own as a result.