In a paper published a few days ago, it was shown that out of 275 women of diverse backgrounds, foreign-born women were half as less likely to experience menstrual chocolate craving, compared to women born to U.S.-born parents, and two-and-a-half times less likely than second generation immigrants.

In fact, the researchers have noted in their paper that only 6% of Egyptian women and only 28% of Spanish women experience craving chocolate in general (not just before their period), as opposed to 90% of American women.

And what makes things more interesting is the fact that the researchers have found that women with the most cravings are more "westernised" than the ones without cravings, reporting "significantly greater U.S. acculturation and lower identification with their native culture than non-menstrual cravers."

So, things are simple: the more TV a woman watches, magazine articles she reads, and the more she chats about premenstrual chocolate cravings, the more she will experience them herself. But what about the weather, sedentary lifestyle, indoor living etc.? Don't these play a role in chocolate cravings before the period?

"Not specifically," explains Georgios. "The researchers have found in this study that there were no significant differences between the three groups in the prevalence of non-chocolate food cravings or in the prevalence of regular, non-PMS related chocolate cravings."

"This means that boredom, stress, sedentary/indoor living and weather cannot be blamed for the differences in increased PMS cravings of first generation, second generation immigrant or 'native' women: they all experienced normal, day to day (non-PMS) chocolate cravings equally," says Georgios.

"In previous research, scientists have found that, contrary to popular belief, PMS is not related to fluctuations of estrogen and progesterone, so the use of contraception and altered menstrual cycle regularity in Western women cannot be blamed either," Georgios states.

But how did those PMS chocolate cravings start in the first place?

The two scientists who have conducted this study believe that the constant struggle to remain slim in U.S. popular culture pushes women to find socially and personally acceptable excuses to consume "taboo" foods like chocolate, such as PMS and pregnancy.

On the other hand, nicotine craving seems to indeed be related to hormonal fluctuations before periods, while alcohol cravings (another taboo for constant dieters) are also increased before the period.

"The former is indeed a proven physiological response, while the latter may be either a physiological response and/or a convenient excuse to consume alcohol, blaming it on the PMS," explains Georgios.

In summary, and despite some limitations, this study has shown that immigrants to Western countries have an initial health advantage, in comparison to local populations, with lower risk of overweight and related diseases. However, by adopting westernised food, that advantage dissipates.

So, next time chocolate cravings hit, female hormones should not be blamed. PMS seems to be a convenient excuse to break that strict eating regime and "let loose" for a few days.