The idea that pregnant women crave bizarro foods (pickles, ice cream) is a well-established one, and you probably assume it has to do with nutritional needs for the baby … or … something. And so no one would think to discourage pregnant women from indulging in them. But researchers have actually never been able to come up with a convincing biological explanation for pregnancy cravings, according to a new paper in Frontiers in Psychology that takes a close look at the most commonly reported pregnant-lady craving: chocolate.
Cravings aren’t explained by hormones, for one; most studies show that fluctuating hormones don’t have much of an effect on the frequency or intensity of chocolate cravings. And it’s not likely explained by the caffeine in chocolate, either; moms-to-be aren’t likely drawn to chocolate for an energy boost, because there just isn’t enough caffeine to have an effect on most people. (A 60-gram serving of milk chocolate only contains 12 milligrams of caffeine; compare that to one eight-ounce cup of coffee, which contains up to 200 milligrams of caffeine.)
Another guess is that maybe there’s something in chocolate that corresponds to a nutritional need. But Orloff writes that if this were true, more pregnant women would crave foods high in nutrients that are particularly important during pregnancy, like folate, iron, and magnesium. (But you don’t exactly hear a lot about an overwhelming urge to consume dark leafy greens or beans.) And the cravings are also unlikely to be caused by a need for a general increase in calories — that whole “eating for two” thing — because cravings tend to start during the first trimester, “long before a majority of fetal growth (and thus fetal demand for nutrients),” write the authors, led by Natalia C. Orloff, a graduate student at SUNY – Albany.
Cravings in pregnancy, the authors argue, probably tell us more about our minds than our biology. Because cravings in general tend to be triggered by the idea that a food is “forbidden,” the more off-limits a food is, the more we’ll want it, research has shown. And pregnancy may be the one “socially acceptable time for women to indulge” in these food cravings, Orloff and colleagues write. Calling the urge for a specific snack a craving makes it sound like there’s some kind of biological pull happening, which makes it okay to give in, in other words.
So why does it matter where cravings come from? Partially because, when it comes to pregnant women, at least, we afford them a near-mystical power. Orloff and her colleagues worry that this notion of irresistible cravings may be why some American women to gain too much weight during their pregnancies, which can lead to health problems for both the mom-to-be and the baby. Orloff explained the next direction her research will focus on in an email to Science of Us:
The next step for our research is to begin looking at cravings and other possible psychosocial correlates (i.e., restrained eating) longitudinally over the course of pregnancy. The goal of future work in this area is to start to identify what the significant predictors are of excess gestational weight gain and subsequently start to develop interventions to reduce the amount of weight gain and the negative consequences that develop due to excess gestational weight gain.
To summarize, as someone who has never been pregnant: The whole thing seems hard and weird and confusing and apparently you can’t have as much chocolate as I was once led to believe.