I asked myself this question abut a gazillion times when I was pregnant and my pregnant friends ask me this question all the time. I found a few useful resources that I think can help provide an answer, but I'm sure there are more so feel free to add any you've found! As with any question regarding pregnancy, it.s always best to consult a physician. These sites, though, can help you learn more about the role of diet in a healthy pregnancy and begin to answer some of the most recurring questions like: Does fish have too much mercury? Smoked meat too many nitrates? Are artificial sweeteners safe? Can you have too much caffeine? Are all herbal teas okay? Read on for some preliminary answers.