"The path to a woman's heart is through her stomach."

I ignored a great many things my wonderful father said, but this old maxim stuck with me. Women were a colossal mystery to me in my teens (now they're just a mystery), so I clung to anything that would grant me even a meager chance of scoring a date.

Now, my dad's advice has a study published in a prestigious science journal to back it up.

Reporting in the Proceedings of the National Academy of Sciences, an international team of scientists has found that low blood glucose levels correlate to greater amounts of aggression and anger between spouses. Translation: both men and women are happier with their significant other when they're satiated with food.

Glucose, one of the simplest sugars, is the human body's preferred source of energy. The brain particularly craves glucose, and when it doesn't get enough of the stuff, mental processes like decision-making and self-control fall by the wayside. Deficits in the latter spiral into other deleterious effects.

"People have more difficulty controlling their attention, regulating their emotions, and overriding their aggressive impulses," the researchers say.

With a bounty of prior evidence in tow, the research team, led by Ohio State University psychologist Brad Bushman, sought to test whether low glucose levels contribute to violent tendencies between intimate partners.

For 21 days, 214 participants from 107 heterosexual couples measured their glucose levels each morning before breakfast and each evening before bedtime. To gauge their aggression, every participant was given a voodoo doll and instructed to stick between 0 and 51 pins in it each evening depending upon how angry they were with their spouse. The quirkily macabre procedure was to be completed in private and the results recorded.

Once the 21 days concluded, participants were brought into the lab and told that they would be competing with their spouse in a very basic computer game involving pressing a button as fast as possible. Winners were allowed to blast the loser with a cacophonous mixture of sounds like fingernails scratching on a chalkboard, dentist drills, and ambulance sirens, at an intensity and duration of their choice.

"Basically, within the ethical limits of the laboratory, participants controlled a weapon that could be used to blast their spouse with unpleasant noise," the researchers described.

In reality, subjects were competing against a computer and randomly lost 13 of the 25 trials. When debriefed at the end, only 3 of the participants suspected the ruse.

The results were revealing. After controlling for relationship satisfaction and gender, the researchers found that daily evening glucose levels predicted sticking fewer pins into the voodoo dolls. In other words, on nights where a subject's glucose levels were lower, they felt more anger towards their spouse.

For the computer-based aggression test, the researchers averaged subjects' evening glucose levels, finding that lower levels predicted higher aggression in the task. Subjects with lower average glucose levels punished their spouses with louder volumes and longer durations of noise.

The study's approach was a strength, in that it tested subjects in their own homes as they carried out their normal habits. But such a design allows for confounding variables to seep in. Could alcohol intake have affected the voodoo doll results? Or what about the time that participants performed their nightly "stabbing"?

Overall, the research suggests that partner aggression can be curbed by maintaining blood glucose at normal levels. When you're feeling especially angry towards your spouse for no apparent reason, your blood sugar may be low. So reach for a small glass of orange juice or a snack-sized candy bar, not a frying pan.

Source: Brad J. Bushman, C. Nathan DeWalld, Richard S. Pond, Jr., and Michael D. Hanusa. "Low glucose relates to greater aggression in married couples." PNAS. April 2014.www.pnas.org/cgi/doi/10.1073/pnas.1400619111