Where do those uncontrollable urges for sweet, salty or spicy foods come from? Or the crazy combinations, like olives and cheesecake? There are lots of theories, like the old wives’ tale that desire for chocolate means you’re having a girl. But the truth is there is surprisingly little scientific understanding of exactly what triggers cravings.1
Approximately half of pregnant women in the U.S. experience them.2 A survey by babycenter.com found that 40 percent of women crave sweet, 33 percent salty or spicy, 17 percent citrus, tart or sour, with the remaining 10 percent craving “strange” combinations.
Cravings typically follow a pattern: they start by the end of the first trimester, peak in the second and fade as the pregnancy is carried to term. Research by Valerie Duffy, PhD,3 found that preferences for sour tastes were more likely in the second and third trimesters while cravings for salt increased throughout pregnancy. She also determined that women were more sensitive to bitter tastes during the first trimester, which could serve an evolutionary function by protecting the fetus from poisons or substances that could be harmful to baby and mother during early stages of development.
Folk wisdom holds that cravings are the body’s way of signaling the need for nutrients or foods that address particular metabolic functions. But there is little hard evidence connecting cravings and nutritional requirements. And it has been pointed out that women typically crave a very specific food, not the food group that would satisfy various nutritional needs.4,3 It’s also striking that American women, in particular, often choose high-calorie, sugary, fatty foods.5,4 So, for instance, why crave chocolate instead of red meat, egg yolks or dark leafy greens for iron? Or beans and lentils for folate, iron and magnesium? Or tofu instead of ice cream for calcium? (Well, OK… that one seems obvious, even to a nutritionist!)
This isn’t saying that cravings aren’t real. In fact, they’re common around the world, which seems perfectly reasonable considering the tremendous hormonal changes that occur during pregnancy and how much they influence how things taste and smell. (This includes the flip side of cravings—food aversion, the most common being to meat.)6,3
But it turns out that cravings are very different in other parts of the world. Chocolate cravings are virtually unheard of in Egypt. In Japan, pregnant women desire rice. In Tanzania, meat and fish, vegetables, fruits and grains.7,4
Aside from cultural factors influencing cravings, there could be psychological elements involved, too. In the U.S., where women have very complicated relationships to food and desired body image, it has been proposed that pregnancy may provide “permission” to eat foods that would normally be avoided.8,4 A physician’s suggestion to add more dairy might also trigger a sudden urge for ice cream.9,3 Keep in mind, these psychological elements don’t dismiss cravings or attempt to “blame” women for them. They are part of a complicated group of contributing factors that aren’t well understood.
Another contributing factor could be leptin, an endocrine growth factor involved in regulating appetite and stimulating metabolism.10,5 Pregnant women are resistant to leptin, which causes a chain reaction of several different internal control mechanisms to increase appetite. That’s a very positive part of mother and baby’s nutrition, but still unclear as to its exact connection to cravings for specific foods.
There is one condition called pica that requires a note of caution. Pica involves craving non-food items, such as dirt, laundry starch, crayons, clay or ice. Aside from potentially interfering with normal nutrition, there is an associated danger of ingesting lead—which is dangerous for both mother and baby.6 If experiencing such cravings, you should check with your physician right away.
Cravings for foods that may increase your risk of food poisoning or listeria should also be discussed with your doctor.
Otherwise, following your cravings within reason is perfectly acceptable.11,1 But try to maintain a balance with the most nutritional food choices—and every once in a while, consider frozen yogurt instead of ice cream or baked sweet potato “fries” instead of French fries.
1 Ward, E. M. (2006, June 1). Coping With Pregnancy Food Cravings. Retrieved March 15, 2017, from http://www.webmd.com/baby/features/coping-with-pregnancy-food-cravings#1
2 BabyCenter Medical Advisory Board May 2016. (2016, December 19). Food cravings and what they mean. Retrieved March 15, 2017, from https://www.babycenter.com/0_food-cravings-and-what-they-mean_1313971.bc...
3 Brody, S. (2015, June 11). Pregnancy Cravings. Retrieved March 15, 2017, from http://www.parents.com/pregnancy/my-body/nutrition/pregnant-cravings/
4 Orloff, N. C., & Hormes, J. M. (2014). Pickles and ice cream! Food cravings in pregnancy: Hypotheses, preliminary evidence, and directions for future research. Frontiers in Psychology, 5. doi:10.3389/fpsyg.2014.01076
5 Graves, A. (2010, July 28). The Mystery of Pregnancy Cravings. Retrieved March 15, 2017, from http://www.bu.edu/synapse/2010/07/28/the-mystery-of-pregnancy-cravings/
6 Bouchez, C. (2008, October 08). Pregnancy Cravings: When You Gotta Have It! Retrieved March 15, 2017, from http://www.webmd.com/baby/features/pregnancy-food-cravings