Examining food choice of human females from the evolutionary perspective: The role of sexual selection

From the perspective of evolutionary psychology, sexual selection played important roles in the evolution of human psychology and behavioral phenotype. For example, studies showed that both risking behavior in males and prosocial behavior in females were partly shaped by sexual selection. However, the influence of sexual selection on females’ food choice has not been given much attention or systematically examined. As we know, food choice plays an important role in body shaping. Body mass is directly related to intake of high-fat food. To lose weight or shape body figure, many females look to dieting and healthy food intake. Also, females’ body mass and body shape are related to health and reproductive value. All the evidence suggest that food choice might be strongly selected by sexual selection in females.

To systematically explore the role of sexual selection in female food choice, two kinds of studies would help. The first kind of study is to experimentally manipulate mating motive and then record the change of food choice in females. This kind of study makes us possible to understand the causal relationship between mating-related cues and female food choice, which helps understand the role of sexual selection in female food choice. Theoretically, the salience of mating motive would make both males and females show signals that enhance their attractiveness in the eyes of the opposite sex. Since a low BMI and an attractive body shape are essential indexes of body attractiveness as well as signals of females’ reproductive value, and food choice contributes to fluctuation of BMIs and body shaping, it is not hard to speculate that priming of mating motive would cause an effect on female food choice. Meanwhile, we should diversify methods used to manipulate mating motive and explore the types of food that might be influenced by mating motive, so as to have a better understanding of the relationship between mating motive and female food choice. The second kind of study relies on examination of the fluctuation of female food choice across menstrual cycle. Female menstrual cycle is largely shaped by sexual selection and is accompanied by fluctuation of hormones such as estrogen and estradiol, which means relevant studies would contribute to understanding the neurobiological mechanisms underlying the link between sexual selection and female food choice. However, the neurobiological basis of the relation between menstrual cycle and food preference has seldom been explored. Besides, sex hormones are regulated by human brain. Examining the brain substrates underpinning the above relation would be invaluable for further understanding the mechanisms involved. Also, human brain might interact with sex hormones in affecting the relation between female menstrual cycle and food choice.

In future studies, we need to examine the role of sexual selection in female food choice from different perspectives and explore the moderating roles of other psychological components in the relationship between mating motive, menstrual cycle and female food choice. For example, previous studies have showed that dinning environment, affective state, cognitive and social factors all contribute to food choice in females. The above factors might interact with mating motive and menstrual cycle to cause an effect on female food choice. Moreover, oxytocin and vasopressin are also neuropeptides that play important roles in maintenance of intimate relationship. Future studies need to explore whether these two neuropeptides also play roles in female food choice as well as potential interacting effects involved. Owing to the difficulty of directly unveiling the dynamics of sexual selection, we have to look to some indirect evidence to understand the true nature of the roles of sexual selection in female food choice. Meanwhile, a brain-hormone-behavior framework would help a lot to systematically understand the role of sexual selection in female food choice.