Fighting with your significant other lately? Before you call it quits over irreconcilable differences, take a look at your diet. Turns out the source of many interpersonal frustrations may have more to do with your blood sugar level than how compatible you are with your mate.

A team of researchers at The Ohio State University led by Brad Bushman, Ph.D., tracked the nightly blood sugar levels of 107 married couples (most of whom had been hitched at least a decade) for three weeksLow glucose relates to greater aggression in married couples. Brad J. Bushman, C. Nathan DeWall, Richard S. Pond, Jr., et al. PNAS. 2014 Apr 29;111(17):6254-7.. Participants also received a voodoo doll representing their spouse and were instructed to stick up to 51 pins in it as a way of marking how angry they were with their partners.

Following this 21-day stretch, spouses competed against each other in a lab-based computer game. The goal: Be the first to press a button in response to a red square popping up on their screens. (Spouses played alone in a room, under the assumption that their husband or wife was their opponent. Little did they know they were playing against the computer.) Winners earned the once-in-a-lab-time chance to blast their opponents with ear-shattering noises—fingernails on a chalkboard, dentist drills, and crazy loud ambulance sirens. (Less retaliatory victors could, of course, opt for a “no noise” option.)

Who delivered the most unbearable and lengthy aural assaults to the ears of their beloved? Participants whose blood glucose levels consistently clocked in below normal during the weeks preceding the game. What’s more, the lower their glucose levels were, the more abuse (in the form of pin pricks) their spouse-representative voodoo dolls suffered. Ouch.

Why Hunger Makes Us More Likely to Lash Out

So what the heck is it about hunger that it makes us likely to hulk out? “Anger is one of the most difficult emotions to regulate,” Bushman says, explaining the connection between low blood sugar and aggression. “Without adequate fuel in the form of glucose, the part of the brain responsible for curtailing angry impulses—the prefrontal cortex—simply doesn’t have enough resources to exert self-control.”

Research confirms that hanger is a legit problem.

Previous research has confirmed that hanger is a legit problem. In one study using a similar computer game setup, players who slurped down a pre-competition sugary lemonade delivered less vicious bombardments to their competitors’ eardrums than those who’d chugged calorie- and sugar-free drinksSweetened Blood Cools Hot Tempers: Physiological Self-Control and Aggression. C. Nathan DeWall, Deckman T., Gailliot M., et al. Aggressive Behavior. 2011 Jan-Feb;37(1):73-80.. In another, folks unable to properly metabolize sugar—a hallmark symptom of diabetes—were less inclined to forgive a wrongdoer. And by the way, single folk among us are not immune: Depressed glucose levels have also been cited as a primary cause of increased irritability around others (friends and lovers included), over-the-top anger, and general anxietyThe physiology of willpower. Personality and Social Psychology Review. Gaillot M.T. & Baumeister R.F. 2007 Nov;11(4):303-27..

“We’re not advising people to binge on sugar just to get along with their partners,” Bushman says. “But if you have something important to discuss with a significant other, you should avoid doing it on an empty stomach.”

For better noshing that keeps us both energized and healthy, sports dietitian Heather Mangieri, MS, RDN, CSSN, recommends constructing snacks as mini-meals—half a turkey sandwich with an orange or an apple with peanut butter. “The point of a snack is to hold you over, maintain your blood sugar, and supply your body with the vitamins and minerals it needs,” Mangieri says. “People often forget this because they associate snacking with something crunchy, salty, sweet, or processed.”

If you have something important to discuss with a significant other, you should avoid doing it on an empty stomach.

Healthy eating may not make relationship conflicts disappear. But properly nourishing our bodies can help us control anger and iron out issues with our loved ones by energizing us enough to manage strong emotions.

The Takeaway

Going from hungry to hangry is a legit problem—and it can make us hostile toward those closest to us. We’re more easily irritated when we’re running on empty because our brains don’t have enough fuel to tamp down aggressive thoughts and impulses. Self-control takes energy—in the form of food and drink that keep you sated and energetic throughout the day. Don’t be shy about keeping a decent supply of easy-to-carry, non-perishable snacks on you or at least within reach, especially if you’re susceptible to hanger-induced ragefests. Preventing hunger means preventing hanger, which means your body, brain, and significant other will all have something to thank you for.