Before the cramps kick in, before the swollen boobs, and before the mood swings, I get one tell-tale sign PMS has arrived: I can’t stop eating. I could be mid-salad, happily munching away, and all of a sudden, it’ll hit me. I need a very large bowl, I need it to be filled to the top with tater tots, and I need it right now.

PMS cravings are powerful — and you have your hormones to thank. “PMS causes the stress hormone cortisol to go up and the feel-good hormone serotonin to go down,” explains Carolyn Dean, MD, ND, Medical Advisory Board Member at the Nutritional Magnesium Association. “This change makes your body crave foods with lots of sugar and fat because they increase levels of serotonin (the body uses carbs to make serotonin) and fight cortisol production, making you feel better and happier.”

So that explains my tater tot mania — they’re essentially a major mood boost in tiny potato form. There’s something else at work, too, though. Magnesium levels also drop right before your period, says Dr. Dean. “Magnesium regulates cortisol, so if there is more cortisol before [your] period and less magnesium to regulate it, then cortisol wins out and causes more stress-related symptoms.” Plus, serotonin, a feel-good brain chemical that dips when you’re experiencing PMS, depends on magnesium for its production and function, she explains. “Numerous studies have shown [magnesium’s] effectiveness in boosting mood, lowering anxiety and depression, and reducing stress levels, as well as helping with deeper more restful sleep.” (Often issues that get worse with PMS.)

Though you’ll find a lot of magnesium in dark, leafy greens, salmon, and avocados, you probably find yourself gravitating to the shelves of chocolate in the grocery store, not to the swiss chard, right? That’s because chocolate — in particular, dark chocolate — is not only packed with magnesium, it gives you that sugar-induced serotonin boost, basically doing double-duty to battle your PMS blues.

And if you feel like your cravings are particularly intense during certain times of the year — like the winter — or when you’re going through a tough time emotionally, you’re not imagining it. “[PMS symptoms are] made worse under stress or other trying times, such as seasonal affective disorder — which also increases carbohydrate cravings,” says Rachel Carlton Abrams, MD, board-certified physician in family and integrative medicine and author of BodyWise: Discovering Your Body’s Intelligence for Lifelong Health and Healing.

So what’s a PMSing lady to do, besides curl up in bed spooning a bowl of potatoes? “One solution would be to reduce or eliminate processed foods, caffeine, and refined carbohydrates in the two weeks leading up to your period,” says Dr. Dean. Get those magnesium levels up, too — and not just before your period. 65 percent of women ages 19-30 and 48 percent of women ages 31-50 ingest less magnesium from food than their estimated average requirements, but almost all of those who take a supplement meet their requirements, so a supplement could be a good start. “[Start] supplementing with an absorbable form of magnesium such as magnesium citrate powder mixed in water and sipped throughout the day,” Dr. Dean recommends. A few diet adjustments can go a long way, too. “Increasing your intake of fiber and protein can all stabilize your blood sugar and your hormone production,” she says.

And if you’re still craving something sweet and carby, give yourself a break — and permission to indulge a bit. If you’re tuning out the natural ebb and flow of appetite and feel guilt, shame, and pressure to restrict, says Adina Pearson, RDN, you’re more likely to get stuck in a restrict-binge cycle. “Instead of casually enjoying the extra chocolate you desire and then going back to ‘normal’ as your body prompts, the fear of overdoing it will become a self-fulfilling prophecy.”

Message received — now pass the tater tots.

Diana Vilibert is a freelance writer and copywriter living in Brooklyn, NY. She loves flea markets, martinis, to-do lists, traveling, and wearing leggings as pants. You can see more of her writing at www.dianavilibert.com and follow her on Twitter at @dianavilibert.