12 Diet Questions Answered

Caffeine Please

Are you feeling jittery or experiencing insomnia or heartburn? If so, you may want to go easy on the joe. "On average, most adults will notice no side effects from caffeine at 300 milligrams or fewer a day," says Herbert Muncie Jr., MD, chairman of the department of family medicine at the University of Maryland School of Medicine in Baltimore. That's the caffeine equivalent of roughly 28 ounces (or three and a half cups) of regular coffee. If you're pregnant or trying to conceive, "reduce your intake to one caffeinated beverage a day," says Lisa Mazzullo, MD, an assistant professor of obstetrics at Northwestern University Feinberg School of Medicine in Chicago and coauthor of Before Your Pregnancy (Ballantine, 2002). Consuming too much caffeine may increase your risk of low birth weight or miscarriage.