This study is Irish, so I think they likely use 170ml cups? That means a normal mug of ~500ml is 3 cups.
Perhaps they even use US coffee cup size, which is 118ml?
Honestly, using an unit of measurement that varies from 118ml to 250ml in a scientific paper brings the whole paper into question.
> a normal mug of ~500ml
woa where is half a liter of coffee a "normal" portion?
Okay, you'll definitely have to explain the NORMAL mug of HALF A LITER!
The reactions to your comment got me curious enough to check. The mug I use for coffee and tea holds almost exactly 400 mL when comfortably full and I used to drink 2 of those per day (across 12 hours or so). Based on that, personally I'd consider ~800 mL of black coffee to be on the high end of moderate consumption.
I’m Irish.
A NORMAL mug of 500ml??? this is insanity to me
Does it matter what size the cup is? Usually you get the same amount of coffee water + additional water/milk/whatever.
????