It's not genetically determined, it's probably culturally learned.
This is according to a study published in the scientific publication PLOS ONE. In America, 50 percent of women say they like chocolate. There are several old hypotheses that it may have to do with fluctuating hormones or nutritional deficiencies during menstruation. New research claims otherwise:it has to do with norms within the culture you live in.
Notable differences
Women who live in America, but have parents who were born in another country, have just as much appetite for chocolate during their period as women born in America. A notable difference is that these women do not believe that their menstrual cycle has anything to do with it. Only 17 percent of women born in other countries indicated that they wanted chocolate.
In other countries too, research has been done into cravings for chocolate during menstruation. In Spain, 28 percent of women feel like chocolate during the monthly period. In Egypt, this turned out to be the case for only 6 percent of women.
Do you feel like chocolate more when you have your period?
Cravings seem to vary by culture. That's not to say you don't deserve a triple chocolate chip cookie or that the craving isn't real. There is a chance that it is more in your head than in your body.