Food cravings and aversions are a common phenomenon, especially among pregnant women (6, 10). These changes typically start towards the end of the first trimester and increase in the second trimester (6), resulting in at least one aversion of a food they previously loved (3). Sometimes causing a craving for food they disliked before pregnancy (6). Though cravings and aversions aren’t generally related to each other, a significant correlation between morning sickness and nausea has been noted. Over 60% of pregnant women in one study reported that aversions and nausea began the same week of pregnancy (5). These aversions are no joke, and many women report extreme changes in taste: “I used to love cran-apple juice. After I got pregnant, I couldn’t even choke it down - it tasted like pure alcohol to me. I still can’t drink it 15 years later”(1).
We surveyed nearly 800 women about the foods they loved and hated when pregnant. While many women had some really obscure food preferences, a few patterns emerged. One trend was the disdain of strong smells. As one Kindara community member described it, "Anything cooked or strong smelling was off the menu. Fried onions were the worst!" (1).
Why does this phenomenon occur?
Many theories exist on what causes cravings during pregnancy, but evidence to support any of these claims is insufficient. Below is a breakdown of the current theories and why they aren’t supported by science.
Hormonal or sensory changes theory: This theory makes logical sense but doesn’t account for why pregnant women have aversions to some foods and not others (10). In other words, if the change was purely sensory caused by hormone fluctuations, why wouldn’t someone be averse to all foods rather than only a few? Additionally, one study found that increased smell sensitivity was increased for pregnant women depending how far along they were in the pregnancy, with most women (about 2/3) reporting increased sensitivity at week 16 (2).
Nutritional deficiencies theory: Many believe nutritional deficiencies are to blame for cravings, but more evidence suggests that nutritional deficiencies cause pica, a condition defined as persistent eating of non-nutritive substances like clay or soil, rather than cravings. The case against this point is that pica can be seen in anyone, not exclusively pregnant women (6).
Potentially pharmacologically active ingredients in craved foods theory: A commonly-used example is chocolate, which contains a group of potentially pharmacologically active ingredients called methylxanthines. These methylxanthines are said to be energizing, but a normal serving of chocolate doesn’t contain enough of them to have an effect on anyone except the very sensitive (6).
Cultural and psychosocial factors theory: In other words, being told “you’re eating for two” or having the social approval or disapproval to eat certain foods may have a powerful effect on the eating habits of pregnant women (10). Cultural norms also have an effect on what cravings manifest; for example, in Japan, cravings for rice are commonly reported, whereas in the U.S., chocolate cravings are the most common (6).
Maternal/embryotic protection theory: This theory suggests that aversions are an adaptation to protect the mother and developing fetus from disease and to help the placenta grow by directing more nutrients to the placenta and less towards the mother (10).
What should I do if I have strong cravings or aversions?
Maintaining a balanced, nutritious diet including fruits and vegetables plus meat, low-mercury fish, nuts, and legumes, which are excellent sources of protein, zinc, iron, and magnesium, is especially important during pregnancy (7, 8, 9). But this is easier said than done if you’re dealing with aversions or cravings. Not to worry! We have a couple tips that might help. If you're craving unhealthy salty or sweet foods, find a similar healthy alternative; for example, substitute a handful of nuts instead of potato chips or fresh strawberries for strawberry ice cream. If you find yourself with an aversion to red meat, try to eat other foods that provide plenty of protein, like poultry, pork, eggs, or beans (8).
If your cravings and aversions steer you in an unhealthy direction, talk to your health care provider. Of course indulging in moderation is OK, but eating healthy is important for both you and your baby. As always, keep in touch with your doctor to make sure you’re getting the nutrition you need for a healthy pregnancy and a healthy baby.
Lopez, L. B., Langini, S. H., & Pita de Portela, M. L. (2007). Maternal iron status and neonatal outcomes in women with pica during pregnancy. International Journal of Gynaecology and Obstetrics: The Official Organ of the International Federation of Gynaecology and Obstetrics, 98(2), 151-152.