A voodoo doll used in the study to measure participants’ anger with their spouses. Photo by Jo McCulty, Ohio State University

Some days it seems that, despite your best intentions, it’s inevitable the bickering will escalate into a full shouting match.

But the answer may be as simple as eating a little chocolate or taking a few bites from a plate of pasta.

New research reveals that lower levels of blood sugar may make married people angrier at their spouses and even more likely to lash out.

In a 21-day study of 107 couples, researchers found that levels of blood glucose in married people measured each night predicted how angry they would be with their spouse that evening.

Those who had lower levels of glucose were willing to blast their spouses with unpleasant noises at a higher volume and for a longer time than those who had higher glucose levels.

Brad Bushman, lead author of the study and professor of communication and psychology at The Ohio State University, says blood glucose levels can be brought up quickly by eating carbohydrates or sugary foods.

“People can relate to this idea that when they get hungry, they get cranky,” Bushman said.

It has a slang term: ‘hangry’ (hungry + angry).

“We found that being hangry can affect our behavior in a bad way, even in our most intimate relationships,” he said.

During the study, participants were given a voodoo doll they were told represented their spouse, along with 51 pins.

At the end of each day, for 21 consecutive days, the participants inserted 0 to 51 pins in the doll, depending on how angry they were with their spouse.

They did this alone, without their spouses being present, and recorded the number of pins they stuck in the doll.

Each person also used a blood glucose meter to measure glucose levels before breakfast and every evening before bed for the 21 days.

The result: The lower the participants’ evening blood glucose levels, the more pins they stuck in the doll representing their spouse. This association was present even after the researchers took into account the couples’ relationship satisfaction.

Why does low blood sugar make people more prone to anger and aggression?

Glucose is fuel for the brain. The self-control needed to deal with anger and aggressive impulses takes energy and that energy is provided in part by glucose.

Bushman said:

“It’s simple advice but it works: Before you have a difficult conversation with your spouse, make sure you’re not hungry.”

The study, which took three years to complete, appears in the journal PNAS (Proceedings of the National Academy of Sciences).

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