I didn't, until yesterday, that is.
How I managed to live a full life without knowing this fascinating piece of trivia is beyond me.
It's around 10-14kg a day, just in case you're interested. Yeesh.
That little nugget of information came from the offices of the Royal Zoological Society of Scotland (RZSS), which can mean only one thing: it's panda-monium time again.
Cue the handstands of Yang Guang, the twice-daily urine samples and swabs of Tian Tian, and more webcams trained on their Corstorphine 'love nest' than seems polite.
Talk about performance anxiety.
I love animals – I'm a borderline puppy stalker – but the hype surrounding the pandas has put me off forking out £15.50 and then queuing up to see them in the flesh... sorry, fur.
Call me an old grump, but I just don't want to receive an update every time one of their bowels has moved since they arrived 14 months ago.
Can you imagine the fuss there will be if we do hear the pitter patter of tiny panda paws?
I wonder which politician or celebrity will score the first photo opportunity with the little blighter.
The irony is, if Tian Tian was a human, and not a hulking great beast, then the mother-of-two would be breaking her own country's one-child policy.
All this fuss to make one panda procreate in captivity seems obscene when the basic rights of women in China continue to be compromised in such a draconian fashion.
In the half-decade of diplomatic negotiations with China that it took to bring the pandas here, I doubt very much that the subject of human, rather than animal, rights was ever broached.
With Edinburgh Zoo stating that it will use 'natural' as well as 'assisted reproduction' this time, it's also ironic that the panda courtship coincides with the National Institute for Health and Clinical Excellence (NICE) publishing its guidelines for provision of fertility treatment on the NHS.
NICE recommends upping the age limit to 42 – three years younger than Cherie Booth was when she gave birth to her youngest child, Leo.
And anyone undergoing infertility treatment will be only too aware of the postcode lottery in provision that already exists: the different age limits, the varying number of cycles offered and the wide-ranging waiting wtimes depending on where you stay.
But these couples are missing a trick. What they really ought to do is dress up in panda suits, develop a taste for bamboo and £250,000 enclosures, and then they'd be laughing.