A new study tells us that succumbing to cravings during your time of the month is totally normal—but worrying about them can cause harm

We don't need science to tell us that PMS causes many women to eat more than normal (the emergency stash of chocolate in your desk is proof enough). We're all too familiar with the monthly cycle of craving junk food, eating too much, then feeling bad (and bloated!). But what you may not know is that your body is doing exactly what it's supposed to do-raging chocolate cravings and all-says a new study looking at hormonally-driven weight gain and what it does to us.

Monthly changes in food intake are all part of a natural, evolutionary process, says Kelly Klump, PhD, a professor at Michigan State University and lead author of the paper, which was recently published in the International Journal of Eating Disorders. Our estrogen and progesterone levels naturally fluctuate over the course of our cycle, and this hormononal roller coaster ride can cause increased hunger, programming us to eat up to 1,000 extra calories a day in preparation for growing a fetus. In addition, the hormones can inspire emotional eating, or eating as a way to deal with negative emotions. Both of these, obviously, can cause us to gain weight. (Check out these 6 Foods You Can't Overdo.)

However, the research proves that the problem isn't the emotional eating or even the weight gain-they are both totally normal-but with our reaction to those biological drives. This tendency to eat emotionally and the subsequent weight gain leads many of us to a particularly bad type of self-loathing. Who hasn't stood in their closet a week before Aunt Flo's scheduled visit and wailed, "Everything makes me look fat!"? And the kicker is the worse we feel about ourselves, the more we eat.

In the past, these female fluctuations weren't seen as cause for alarm, but, Klump says, "In our culture, we tend to view any increased eating by a woman as a negative thing, even when it is biologically- and evolutionarily-driven. This is a potentially dangerous chain of events that could lead to serious and life-threatening eating disorders, including anorexia nervosa and bulimia nervosa." She adds that this can be especially problematic during the holidays, with the increased pressure both to indulge and to look good.

So how do we break this vicious cycle of hormones, cravings, weight gain and body hate? When it comes to the first three, you really can't, Klump says, so we instead need to focus on letting the body do its thing and not judging ourselves for it. Just understanding how our hormones work can help alleviate some of the stress and angst-and can even help keep the emotional eating in check in the future. And the sooner we can make peace with our hormones, the better. Because if one thing's for sure, it's that Mother Nature will be back next month. (But, if you're feeling guilty after a sudden food binge, here's Your Post-Pig-Out Plan.)