One damaging effect of the US failure to switch away from imperial measurements is that most people are confused about coffee consumption data. From the article

One damaging effect of the US failure to switch away from imperial measurements is that most people are confused about coffee consumption data. From the article: > Patients would report drinking just a few cups of coffee a day, only to reveal that their idea of one cup was a forty-ounce thermos. “At three of those a day, they were drinking more than 1,000 milligrams of caffeine,” Cherniske says. This is an extreme example, but even a much less extreme case is commonplace and problematic. A large cup (the vessel) of coffee at most cafés is 20oz--but that's 5 cups (the imperial unit of measure). A study I read a few years ago tracked people's moods and found that people's moods correlated higher with coffee intake peaking at 3 cups, dropping at 4 cups but still remaining positive, and then plummeting into the negative at 5 cups. A single large coffee at many cafés will already put you at the 5 cup range.