What is it about pregnancy that can turn a meat-eater against beef or make a vegetarian crave steak? How can it make one woman gaga for guacamole and another barf at the sight of broccoli? Some of it is hormone-related, says Janet Pope, Ph.D., an associate professor of nutrition and dietetics at Louisiana Tech University in Ruston. Just as women have cravings at various stages of their menstrual cycle due to hormones, the same thing happens during pregnancy. Some theories hold that there is also a wisdom of the body. A craving for milk might mean you need calcium; a craving for fruit may signal a need for vitamin C. In fact, fruit, milk, and milk products (as well as chocolate and salty snacks) are the most common pregnancy cravings, says Dr. Pope.
One thing we do know is that a woman’s taste preferences change throughout pregnancy and these changes may affect what she chooses to eat. For example, moms-to-be tend to have a greater affinity for sweet foods (hello, chocolate!). Scientists think this could be caused by an increased need for calories during pregnancy. Research conducted by Valerie Duffy, Ph.D., an associate professor in the School of Allied Health at the University of Connecticut in Storrs showed that women:
Liked sour tastes more in the second and third trimesters than in the first trimester or before pregnancy
Like a preference for sweet tastes, a sour preference helps women get a more varied diet later in pregnancy so they can get enough calories, says Dr. Duffy. A yen for sour foods also seems to explain the classic pickle craving. And since fruit is typically a combination of sweet and sour tastes, it also explains why fruit is the most common pregnancy craving.
Showed an increased preference for salty tastes — which would include foods like potato chips and pickles (again!) — as their pregnancy went along.
During pregnancy, a woman’s blood volume increases, so this taste change may be tied to her greater need for sodium.
Had an intensified perception of bitterness during the first trimester
Scientists suspect that being able to isolate bitter tastes during pregnancy is an evolutionary protection because many toxic plants and fruits taste bitter. This taste change helps warn pregnant women against consuming poisons, such as alcohol, during critical phases of fetal development, agrees on Dr. Duffy. Interestingly, the aversion to bitter tastes typically lessens by the third trimester, when the crucial phases of fetal development have ended.