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, PhD, 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, PhD, 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 Dr. Duffy. Interestingly, the aversion to bitter tastes typically lessens by the third trimester, when the crucial phases of fetal development have ended.
Unfortunately, though, taste changes that perhaps started as genuine biological or physiological needs before food was plentiful can backfire, particularly in developed countries. These changes that allow you to eat enough for appropriate weight gain can cause you to eat too much, says Deborah Bowen, PhD, a professor of public health science at the Fred Hutchinson Cancer Research Center in Seattle. For instance, an increased desire for sweets in a society where a candy bar or carton of ice cream is just a ride away could lead you to put on too much weight, not to mention that eating candy all day isn't very nutritious. And excessive weight gain can increase your risk of gestational diabetes and high blood pressure.
A woman of average weight needs to gain 25 to 35 pounds when pregnant; that equals only about 300 extra calories a day. Ideally, those calories should come from healthy foods, says Joanne Stone, MD, coauthor of Pregnancy for Dummies (John Wiley & Sons). But you don't have to deprive yourself of an occasional treat. If you find yourself craving an excessive amount of sweets, try to choose foods that taste sweet but are also nutritious, such as fruit.
Here are some healthy and satisfying substitutes for unhealthy cravings:
- Instead of ice cream, try sorbet, sherbet, Popsicles, or low-fat frozen yogurt.
- If you're craving doughnuts or pastries, try whole-grain bagels or toast topped with jam.
- Instead of potato chips, try baked chips, pretzels, or light microwave popcorn.
- If you can't stop thinking about chocolate, only eat a few squares instead of a whole bar or just have chocolate milk.
- Instead of soda, drink some flavored seltzer or fruit juice mixed with mineral water.
- When you want cakes, cookies, or pie, try low-fat banana or zucchini bread instead.
Some researchers argue that cravings aren't connected to nutritional deficiencies -- that they are merely a desire, and nothing more. After all, if someone is craving protein, why isn't she reaching for lentils and sardines--both good sources of protein -- rather than beef and bacon? Therein lies the rub -- pregnant women tend to crave specific foods, not every food in a group. It doesn't make sense that a woman would crave pickles but not potato chips if her body needed salt, says Dr. Bowen about two notorious and equally salty cravings.
It's likely that these cravings are the result of biological as well as psychological and environmental influences. The messages women receive during pregnancy, specifically about what kinds of foods they should eat, may in fact cause them to eat or drink more of those foods, says Dr. Bowen. So, if your ob-gyn recommends you add more dairy to your diet, it might trigger a "craving" to drink milk or eat more ice cream than usual.
Expectations about getting cravings might also cause them. Anecdotes that you've heard about women eating pickles for breakfast or your friend's description of her nine-month tomato mania may cause you to have some urges of your own. Of course, cravings for indulgent foods might also stem from a license to eat forbidden foods during pregnancy. The kinds of cravings people get are cultural, too. American women seem to crave chocolate like crazy, but European women don't, says Daniel Fessler, PhD, assistant professor of anthropology at UCLA.
It also makes sense that if certain foods are associated with good feelings during pregnancy, you'll eat more of them. If that's the case for you, indulge, says Dr. Stone. If you're feeling sick, then you should eat what you want, or what you can keep down. Most things in moderation are fine.Food Aversions
If certain foods tend to make you queasy or worse, why take chances? Meat is the most common aversion, according to studies. Dr. Fessler explains that meat and other animal proteins, including eggs and seafood, are more likely to carry food-borne illnesses. So, evolution-wise, women may be predisposed to avoid them.
For many women, it's not only the taste but also the smell of a food that causes the aversion. In fact, there is some evidence that pregnant women have a heightened sense of smell due to hormonal changes, and this impacts which foods they crave and avoid.Unusual Cravings
If you find you crave nonfood items, such as paint chips, laundry starch, or dirt -- a condition known as pica -- do not indulge, as many of these are potentially toxic to you and your baby. Tell your doctor if you're having nonfood cravings; in some studies, pica has been linked to nutritional deficiencies.
Some women also crave foods (such as flour or cornstarch) that, while harmless in small quantities, can lead to gastrointestinal pain or problems if eaten in large quantities. Other foods that may be a health risk during pregnancy include raw fish and raw eggs. Aside from those things that pose a real danger, it's okay to give into cravings, says Dr. Stone. Pickle-cravers everywhere can breathe a sigh of relief.
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