Women eat less when they are in the most fertile stage of their monthly cycle so they can slim down to attract men, a study has found.
Researchers found that those who wanted to maintain an attractive figure were more likely to cut calories, and report a desire to lose weight, at ovulation compared to other times in the month.
While previous studies had found that women changed their eating behaviour around ovulation, it had been thought that this was due to physiological factors, relating to an interaction between their hormone system and nervous system.
But the new findings suggest there is also a psychological reason behind the reduced food intake: one that is related to cultural norms that dictate that a woman may boost her attractiveness to men by managing her weight, the researchers said.
“In our research we saw that shifting levels of hormones interacted with women’s desires to manage their body attractiveness, which predicted an important behaviour – eating less,” said study author Andrea Meltzer, of Southern Methodist University in Dallas.
“These findings illustrate that broader social norms that dictate that thin women are more attractive can play a role, in addition to physiological factors.”
Researchers found that women wanted to maintain an attractive figure and were more likely to cut calories, during ovulation
The findings were confirmed across three independent studies involving three different groups of women.
The first study followed 22 female college students who were not using hormonal contraceptives (which interferes with the natural cycle) and found they desired greater weight loss when they closer to ovulation than when they were not.
The second study followed a further 92 women students, some who were using hormonal contraceptives, and some who were not. Its findings replicated those of the first study: women who were not using hormonal contraceptives reported wanting to weigh less near peak fertility.
In contrast, women in the study using hormonal contraceptives – which act on the endocrine system (glands that produce hormones) to disrupt the menstrual cycle and prevent pregnancy by altering hormonal fluctuations – didn’t demonstrate a desire to lose weight.
A third study followed 89 married women and found that those who were not using hormonal birth control were the ones most motivated to restrict eating during ovulation, but only when they were more motivated to maintain their body attractiveness.
“Not only did the primary effect replicate across three independent studies, it emerged in two samples of undergraduate women from different universities and a sample of married women and did not vary across participants’ weight using two samples of women who had a normal weight on average and one sample of women who were overweight on average.”
Previous studies have shown that women are more likely to wear “sexier” clothes – especially in the colour red – around ovulation, that exotic dancers receive more tips at that time, and that men prefer the smell of T-shirts that have been worn by ovulating women.