Differences in Dietary Intake as a Function of Sexual Activity and Hormonal Contraception

Abstract

As a consequence of the need to downregulate some maternal immune responses so as to tolerate paternal genetic material following conception, the luteal phase of the menstrual cycle is associated with increased susceptibility to infection. Because meat was one of the primary sources of foodborne pathogens throughout our evolutionary history, Fessler (2001) predicted a decrease in meat intake during the luteal phase; the current research provides the first test of this prediction. Based on the assumption that any such behavioral changes would be hormonally mediated, we also investigated the effects of varying levels of exogenous hormones on meat consumption by examining dietary intake in women using hormonal contraceptives. Lastly, because, from a functional perspective, immunomodulation is unnecessary during anovulatory cycles and in women who are not currently sexually active, luteal phase compensatory behavioral prophylaxis was predicted to be absent in these contexts. Although we find that women who are sexually active eat less meat than those who are not, we do not find support for the core prediction regarding effect of cycle phase on meat consumption, nor do we find support for the ancillary prediction that meat consumption would be influenced by the presence or withdrawal of exogenous hormones. We replicate the finding that periovulatory total food intake is decreased compared to the rest of the cycle and find that sexually active women show a greater periovulatory decrease in food intake than sexually inactive women.

Disgust sensitivity in relation to menstrual cycle phase in women with and without an infection

“…During the luteal phase women were also more likely to express behaviors such as cleaning (Dillon, ) or obsessive pulling of hair considered an overexpression of the prophylactic behavior of grooming (Keuthen et al, ). However, Fleischman and Fessler () did not find any decrease in meat consumption in the luteal phase. Meat is one of the primary sources of foodborne pathogens throughout human evolutionary history, as animals carry pathogenic endosymbionts and parasites, and many microbes proliferate on meat (Fessler, ).…”

“…Consequently, modifications of the immune response in early pregnancy prevent the maternal immune system from attacking the genetically half-foreign blastocyst (Szekeres-Bartho et al, 1989;Szekeres-Bartho, Faust, Varga, Szereday, & Kelemen, 1996;Szekeres-Bartho, Par, Dombay, Smart, & Volgyi, 1997). However, progesterone induced immunomodulation-a downregulation of selected forms of immunity (Th1 and NK) increases vulnerability to pathogens and infections (Fessler & Navarrete, 2003;Fleischman & Fessler, 2007, 2011. Thus, according to the Compensatory Prophylaxis Hypothesis (CPH), during periods of increased susceptibility to infections, caused by high concentrations of progesterone (e.g., during the luteal phase of the menstrual cycle or during pregnancy), women should feel more disgusted and increase behaviors that are related to avoidance of infections (Fessler & Navarrete, 2003;Fleischman & Fessler, 2007, 2011.…”

“…The relationship between immunomodulation occurring in the luteal phase and the behavior of women has been tested using different approaches. Fleischman and Fessler (2007) used meat consumption as a proxy of disgust. Other approaches were taken by studies focusing on measuring disgust sensitivity (Fessler & Navarrete, 2003;Fleischman & Fessler, 2011;Jones et al, 2017;Zelazniewicz, Borkowska, Nowak, & Pawlowski, 2016).…”

Using 26,000 diary entries to show ovulatory changes in sexual desire and behavior.

“…The purported function would be to accept higher costs of sex, such as energetic and opportunity costs or sexually transmitted infections, the more likely it is that sex leads to conception. This theory also predicts fertile phase drops in somatic investment, such as food intake (Fleischman & Fessler, 2007;Roney & Simmons, 2017). In this study, we did not assess any non-reproductive motivations, and we collected no data on single women.…”