Many women’s carefully crafted discipline of healthy food habits goes haywire just before their period. As premenstrual emotions and fatigue strike, so do cravings for foods rich in sugar.1 But why do women crave sweets before their period?
Sridevi Krishnan, a nutritional biologist at The University of Arizona, studies factors that affect what food women crave before their period. Many women report that these cravings are specifically for chocolates.2 “I wish we knew [why],” said Krishnan. She believes that there may be a cultural aspect to it; for instance, more Americans reported craving chocolates around their period compared to women from other geographies.3 However, Krishnan noted that women tend to crave sweet-tasting foods, even if it is not chocolate, before their period.
A few reports have offered some clues about why this is the case. Researchers know that estradiol, an estrogen-derived female hormone, contributes to influencing food behavior in rodents; it alters the brain’s sensitivity to the satiety hormone leptin to reduce feeding behavior in mice and rats. 4,5 “[But] this had never actually been looked at in humans,” said Krishnan.
So, Krishnan and her colleagues conducted a clinical trial in 17 women between the ages of 18 and 30.6 They measured the levels of estradiol and leptin in volunteers’ blood throughout the menstrual cycle and also recorded their food habits and cravings.
They observed that the ratio of estradiol to leptin during the luteal phase—the period just before menstruation begins, when both progesterone and estrogen levels are high—corelated with food cravings. Women with a higher ratio reported cravings for sweet and carbohydrate-rich food. “What we saw was that it's not just leptin by itself that determines whether a woman is going to crave high calorie dense foods,” said Krishnan.
Aside from the endocrinal aspects, the team also wanted to pinpoint the central nervous system circuits involved in this food preferences. Other researchers previously showed that leptin suppresses endocannabinoid (EC) signaling—a pathway wherein certain neurotransmitters bind to cannabinoid receptors—that impacts food intake.7 To investigate whether EC or EC-like chemical signaling influenced food cravings, Krishnan and her team carried out an observational study in the same participants as their previous report.8 They measured the concentration of EC neurotransmitters in the participants and used that to model a link to their food cravings. This revealed that women with naturally high levels of oleoylethanolamide, an EC-like chemical that regulates feeding, during the first half of the cycle craved less sugary food during the luteal phase.
“So, I think it's a combination of so many different factors,” explained Krishnan. “It's their leptin-estradiol axis, it's what kind of ECs they are intrinsically making, but also regulated by what kind of diet, especially the fat they [consume], which again, changes what kind of ECs they make.”
The team had also hypothesized that altered insulin sensitivity during the different menstrual cycle phases may influence food habits, but they did not find a link between the two. However, in another small clinical trial with 11 women, researchers observed differences in insulin sensitivity in the brains of participants at different phases of the menstrual cycle.9 They found increased insulin sensitivity after the period during the follicular phase. This reduced as the participants entered the luteal phase, suggesting a shift towards insulin resistance and difficulty in controlling appetite. Although the researchers did not directly test the participants’ food intake in the study, the results could explain why cravings strike just before the period.
Despite being such a common observation, there is relatively less research to explain the basis of period cravings, in part due to the dearth of funding for women’s health-related studies. “It is hard to establish [whether] behaviors that result from craving in the luteal phase alone result in women's health being impacted adversely,” said Krishnan. “Without that evidence, it's going to be hard for scientists to invest more into it.”
- Meneghesso BR, et al. Evaluation of premenstrual syndrome and its relationship with changes in food consumption during the luteal phase in a university center in northwest paulista: A prospective observational cross-sectional study. Int J Nutr. 2022;15(3).
- Osman JL, Sobal J. Chocolate cravings in American and Spanish individuals: Biological and cultural influences. Appetite. 2006;47(3):290-301.
- Hormes JM, Niemiec MA. Does culture create craving? Evidence from the case of menstrual chocolate craving. PLoS One. 2017;12(7):e0181445.
- Matysková R, et al. Estradiol supplementation helps overcome central leptin resistance of ovariectomized mice on a high fat diet. Horm Metab Res. 2010;42(3):182-186.
- Clegg DJ, et al. Gonadal hormones determine sensitivity to central leptin and insulin. Diabetes. 2006;55(4):978-987.
- Krishnan S, et al. Estradiol, SHBG and leptin interplay with food craving and intake across the menstrual cycle. Physiol Behav. 2016;165:304-312.
- Di Marzo V, et al. Leptin-regulated endocannabinoids are involved in maintaining food intake. Nature. 2001;410(6830):822-825.
- Krishnan S, et al. Structural equation modeling of food craving across the menstrual cycle using behavioral, neuroendocrine, and metabolic factors. Physiol Behav. 2018;195:28-36.
- Hummel J, et al. Brain insulin action on peripheral insulin sensitivity in women depends on menstrual cycle phase. Nat Metab. 2023;5(9):1475-1482.
