I remember a recent-ish study that found a strong correlation at 3 or more (or was it more than 3?) coffees in a day, but was inconclusive below that amount. I

I remember a recent-ish study that found a strong correlation at 3 or more (or was it more than 3?) coffees in a day, but was inconclusive below that amount. I don't know what the unit of coffee was (probably standard espresso) and I unfortunately no longer remember the source. There are a bunch of different triggers though and they vary from person to person. Coffee is one I hear very often. For me, the worst is the combination of at least two of {hunger, dehydration, physical activity}.