According to the FDA, 80% of American adults drink caffeine every day, averaging about 200mg a day—the amount in about 2 cups of coffee. But food manufacturers aren't required to include caffeine on labels, so it's difficult to know how much we are getting. Here's a handy guide–complete with calories and sugar, too–for those who like their caffeinated beverages beyond just black.
How much is too much? Limit caffeine to no more than 400mg a day. That's about 3 K-cups, or one Starbucks Venti. Sound unbearable? Try this: Enjoy 1 to 2 cups of coffee in the a.m., and switch to green tea with a splash of milk, a dash of ginger, and cinnamon.