When I think of food cravings I think of the clay-eaters of the South — people who have an unusual craving to eat clay or dirt. In many regions of South America, clay-eating, or geophagy (also known as pica), is also common, particularly among religious zealots and pregnant women. Those who indulge in the practice believe they are satisfying their body’s need for the minerals and other nutrients found in earth. Me, I think I’ll stick to chocolate chip cookies.

BUT THAT would make me out of sync with my gender, according to some surveys.

Last year, a report in the journal Appetite compared the food cravings of men and women in Hispanic and American cultures. In both, researchers learned, more males (about five-eighths of those surveyed) craved salty, spicy foods than chocolate and sweets, while more females (about five-eighths) craved sweets than savories.

The Journal of the American Dietetic Association has published similar findings: Women report significantly more cravings for chocolate and sweets than men do.

The exact mechanisms behind these gender differences in food cravings remain unclear.

The term itself is awfully unscientific. One person’s cravings may be another’s idle desire and someone else’s burning obsession. If you’re like me, the eleven o’clock news stimulates a powerful desire to consume a bowl of ice cream and the aforementioned chocolate chips. This kind of craving can be thought of as the lack-of-willpower and bored-before-bed craving.

The other is not so benign and falls into the category of eating disorder. Although not all clinicians like to go that far. Some euphemistically refer to the desire to satisfy cravings as “emotional overeating” and have concocted a clever acronym, FATS, to describe the four emotions at the core of such overindulgence — fear, anger, tension and shame.

Experts say it’s difficult to explain what mechanism is responsible for cravings. Some blame a powerful psychological dynamic. If foods with pleasurable tastes — that wonderful combination of butter, sugar and salt, for instance — are used to provide comfort in childhood, they could be used to provide solace during moments when, as an adult, you’re consumed by FATS.

Others say cravings represent a physiological need that must be satisfied. “Carbohydrate cravings can simply be from hunger because your blood sugar levels are too low,” says Susan Schiffman, a professor of medical psychology at Duke University Medical Center.

But Dr. Jeffrey Hampl, a dietitian and spokesperson for the American Dietetic Association, doubts that theory. “We don’t fully understand why people crave foods,” he says. “Some people say that it’s a nutrient deficiency that causes us to seek out that food. I don’t believe that’s true. Often the foods that we crave aren’t a good source of that nutrient.”