Or maybe it is just me doing exactly the same thing and therefore noticing every new post containing the word caffeine. Either way, this is interesting:
The study I linked above found that caffeine withdrawal occurs in people who consume as little as 100 milligrams of caffeine per day. But how much is that? As nutrition blogger Colby Vorland pointed out last month, that’s not an easy question. Vorland cites two studies that attempted to measure the caffeine content of coffee. The researchers found that depending on where you get your coffee and how it’s prepared, the caffeine content in a serving can vary from 58 mg to 259 mg. Espresso shots in general had less caffeine than brewed coffee, ranging from 58 to 92 mg per shot; the 259 mg of caffeine was in a 16-ounce cup of Starbucks brewed coffee.
Meaning: I can get away with one espresso a day. Or not. Since one of the problems of caffeine is that no one seems to know how it really works. Does it give you energy immediately? Or much later, so you will not be able to sleep when you drink coffee after lunch? Are there actual withdrawal symptoms? Is it all just a placebo? Are you alert because of your coffee or because you do not have the withdrawal symptoms anymore?