Lower blood glucose levels lead to anger and aggression at spouses, according to a new Ohio State University study.

Brad Bushman, lead author of the study and professor of communication and psychology, said that glucose provides energy to the brain. So, when the glucose levels are down, brain fails to self-control emotions like anger and aggressiveness due to insufficient amount of energy.  

"Even though the brain is only 2 percent of our body weight, it consumes about 20 percent of our calories. It is a very demanding organ when it comes to energy," Bushman said in a press release. "It's simple advice but it works: Before you have a difficult conversation with your spouse, make sure you're not hungry."

For the study, the researchers initially surveyed 107 married couples to determine their relationship satisfaction levels.

Then all the participants were given a voodoo doll that represented their respective spouses, along with 51 pins. At the end of each day, for 21 consecutive days, the participants were asked to insert pins in the doll depending on how annoyed they were with their spouse. At the same time, a blood glucose meter was used to calculate glucose levels before breakfast and before going to bed.

The researchers found that the lower the evening blood glucose levels was, the more pins were struck to the doll.

"When they had lower blood glucose, they felt angrier and took it out on the dolls representing their spouse," Brad Bushman, lead author of the study and professor of communication and psychology, said in a press release. "Even those who reported they had good relationships with their spouses were more likely to express anger if their blood glucose levels were lower."

The participants were then asked to compete with their spouse to find out who could press a button faster after a command. The winner could blast his/her spouse with loud noise through headphones. In reality, the participants were actually playing against a computer as their spouses were in separate rooms during the experiment.

The researchers found that participants with lower levels of evening glucose blasted their spouse with long and loud unpleasant noise than those who had higher glucose levels. They also discovered that those who inserted more pins in the voodoo doll were more likely to be associated with louder and longer noise blasts.

"We found a clear link between aggressive impulses as seen with the dolls and actual aggressive behavior," Bushman said.

Researchers said that blood glucose levels can be quickly increased by munching on carbohydrates or sugary foods.

"People can relate to this idea that when they get hungry, they get cranky," Bushman said. "We found that being hangry ( hungry + angry)can affect our behavior in a bad way, even in our most intimate relationships."

The finding is published in the Journal Proceedings of the National Academy of Sciences.