Pregnancy Cravings and Food Aversions – Shaping Factors

Researchers N. C. Orloff and J. M. Hormes conducted a comprehensive examination of 200 commentary entries authored by expectant mothers, all of which were published across leading U.S.-based pregnancy-focused digital platforms. Through this investigation, they systematically categorized the food items most frequently reported as objects of intensified cravings. The following enumeration is organized in descending order of reported frequency: confectionery products with high simple-sugar content, energy-dense carbohydrate-rich snacks (including items such as pizza and deep-fried potato strips), meat-based products, fresh fruit varieties, high-calorie dairy items characterized by pronounced saltiness (such as aged cheeses and heavy cream), quick-service restaurant offerings, frozen dairy desserts, vegetables exhibiting diverse flavor profiles, and sweetened dairy products with elevated caloric density (e.g., dessert-style processed cheeses, milk-based shakes, or premium ice cream). What underlying biological, psychological, or sociocultural mechanisms might account for this phenomenon? Could the explanation lie in fluctuations of reproductive hormone levels, subclinical deficiencies in essential micronutrients or macronutrients, or perhaps deeply ingrained dietary patterns transmitted within specific cultural contexts?

While the hypothesis that hormonal fluctuations serve as the primary driver behind food cravings and aversions during pregnancy does not provide a comprehensive explanation for these phenomena, substantial evidence indicates that sex hormones significantly influence the dietary preferences of expectant women. Research conducted by M. M. Faas, B. N. Melgert, and P. de Vos using rodent models has demonstrated that estrogens exert an inhibitory effect on appetite, whereas progesterone acts as a stimulant. Comparable findings were reported by N. Geary, who observed that women’s appetites tend to decrease during phases of elevated estrogen production while increasing when progesterone levels predominate. Furthermore, pregnancy is associated with pronounced alterations in taste and olfactory perception—changes that, according to studies in rats, may also be attributable to the actions of sex hormones. S. Nordin and colleagues propose that this heightened sensory acuity may serve a protective function by deterring the ingestion of substances potentially harmful to fetal development. Such transformations in gustatory and olfactory sensitivity lead to distinct shifts in eating behaviors: pregnant women frequently report sudden cravings for foods previously avoided or develop aversions to items they once enjoyed. For instance, in an observational study by C. C. Lawson (2004) involving 105 pregnant women, 65% experienced an aversion to coffee during the early weeks of gestation despite prior regular consumption—a phenomenon potentially linked to increased sensitivity to bitterness. Additionally, M. M. Faas et al. (2010) note a possible reduction in the ability to detect salty flavors among pregnant women, further illustrating the hormone-driven modifications in sensory perception.

A scientific hypothesis posits that the sudden, intense desires for particular foods may represent the body’s adaptive response to the escalating nutritional demands essential for optimal fetal development. Throughout pregnancy, the requirement for trace elements—including iron, iodine, and folic acid—substantially increases, as does the need for caloric energy. Additionally, ensuring adequate intake of docosahexaenoic acid (DHA) and vitamin D becomes critical, given their pivotal roles in neurogenesis and bone mineralization. Despite this, pregnant women frequently exhibit a marked preference for sweet, calorie-dense carbohydrate snacks, which typically lack significant concentrations of essential vitamins and minerals. According to this theory, a more biologically rational behavior would involve an instinctive inclination toward nutrient-dense foods, such as deep-green leafy vegetables, legumes, marine fish, or seasonal fruits. While this pattern is observed in a subset of pregnant women, it does not represent the dominant trend. Consequently, the nutritional deficiency hypothesis fails to fully account for the emergence of specific food cravings during pregnancy, leaving room for continued scientific inquiry and debate.

One of the most prevalent and distinctive phenomena associated with pregnancy is morning sickness, which in some cases progresses to vomiting. Research suggests that specific dietary preferences and aversions—such as avoiding bitter-tasting foods, eggs, or certain types of meat—may serve an adaptive purpose. According to the hypothesis proposed by scientists N. C. Orloff and J. M. Hormes, these reactions represent a defensive mechanism of the body, reducing the risk of food poisoning as well as exposure to potentially teratogenic or abortifacient compounds. Although these symptoms significantly impair the quality of life for pregnant individuals, extensive epidemiological data—including studies by A. E. Czeizel and E. Puhó—indicate that their occurrence correlates with a lower incidence of preterm births. Furthermore, research conducted by R. L. Chan and colleagues demonstrated a statistically significant association between experiencing nausea and vomiting and a reduced risk of spontaneous miscarriage, which may suggest an evolutionary role of these symptoms in safeguarding fetal development.

Undoubtedly, the nature and scope of dietary cravings and aversions experienced by women during pregnancy or in the premenstrual phase are profoundly shaped by the cultural context in which they are embedded. As researchers such as S. Parker, N. Kamel, and D. A. Zellner have documented, chocolate emerges as an exceptionally coveted food item in American society, whereas in other global regions—Egypt, for instance—entirely distinct culinary preferences prevail. Within Indian cultural traditions, this phenomenon is encapsulated by the term *dola-duka*, where *dola* denotes sudden, intense food cravings, and *duka* signifies an aversion to specific food items. Studies conducted in Nigeria reveal that pregnant women there most frequently opt for fruits, vegetables, and cereals, whereas in Tanzania, the dietary focus shifts toward meat, fish, fruits, vegetables, and grains. These variations arise not only from the availability of particular food groups but are also deeply intertwined with established customs and social norms. Nevertheless, the occurrence of pronounced preferences or aversions toward certain foods appears to be a distinctive yet universally observed aspect of women’s experiences across diverse geographical and ethnic landscapes.

Yielding to cravings for high-calorie foods during pregnancy may result in excessive gestational weight gain, which is strongly associated with an elevated risk of gestational diabetes mellitus and preeclampsia. For the fetus, potential consequences include macrosomia (abnormally high birth weight) and an increased susceptibility to overweight or obesity later in life. This issue affects over half of pregnant individuals in the United States, whereas in Vietnam, merely 2.7% of women exceed a 20-kilogram weight gain during pregnancy. Research indicates that cultural dietary patterns—particularly those prevalent in the U.S.—play a pivotal role in this disparity. For instance, Hispanic immigrants residing in the U.S. for less than a decade exhibit a 50% lower risk of excessive gestational weight gain compared to those with longer durations of stay (Chasan-Taber et al., 2008). According to *Institute of Medicine* guidelines, the recommended weight gain during the first trimester ranges from 0.5 to 2 kilograms, with further adjustments tailored to pre-pregnancy body mass index (BMI).

Pica—a compulsive consumption disorder involving non-nutritive substances—may also emerge during pregnancy. As documented by S. L. Young and colleagues, this phenomenon has been observed across nearly all human cultures and in various animal species, suggesting that its origins are not solely cultural but likely linked to micronutrient or macronutrient deficiencies. The most prevalent manifestations include geophagy (ingestion of soil or clay), amylo phagia (consumption of raw starch-based products such as uncooked rice or flour), and pagophagy (excessive ice consumption). A cross-sectional study conducted by Young et al. among pregnant women in Tanzania revealed that pica was more prevalent in individuals with iron deficiency and anemia compared to those without these conditions. While these findings indirectly support the hypothesis that pica is driven by nutritional deficits, other research indicates that both soil and raw rice consumption may impair intestinal iron absorption, complicating causal interpretations. The authors postulate that a third, unidentified factor—such as chronic gastrointestinal inflammation—could underlie both anemia and pica-related behaviors, as geophagy might alleviate symptoms like reflux (via gastric pH neutralization) or diarrhea (through slowed intestinal transit). Estimating pica’s prevalence in Poland remains challenging; however, R. A. Lumish et al. detected it in 46% of pregnant U.S. adolescents who reported at least one instance of craving non-food substances (e.g., ice, raw rice, or baby powder). These individuals exhibited lower serum iron levels. If pica symptoms arise, a complete blood count with iron studies and consultation with the obstetric provider are advised. Although increased appetite, cravings, and food aversions are normal during pregnancy, fulfilling these impulses should be balanced with a nutrient-dense diet and monitored weight gain to mitigate potential health risks.