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Nibble, Then Quibble

March 01, 2015

Finding yourself and your partner on the brink of a spat? First check how long since either of you have eaten.

We all know how easy it is to be grumpy when we’re hungry. Indeed, there’s a connection between our mood and the level of blood sugar — glucose — in the body. Research has found that a low glucose level makes it far easier to express anger — even to behave aggressively — toward the people around us.i Why is this so? Think of glucose as a fuel for the brain. Without adequate fuel, the brain lacks the energy it needs to support optimal functioning. In our intimate relationships, where we regularly bump up against one another’s habits and moods and unique patterns of thinking, optimal functioning includes the ability to exercise self-restraint — to speak kindly, to be patient, to listen carefully and measure our words. Self-restraint is an invaluable skill during arguments and debates. But it doesn’t come easily; self-restraint takes energy. And much of that energy derives from the food we eat, the body’s source of glucose.

Although the brain constitutes only two percent of body weight, it utilizes nearly 20 percent of available calories. It’s a big energy consumer, needing to be “fed” in order to operate at its best.

“Our study shows how one simple, often overlooked factor — hunger caused by low levels of blood glucose — may play a role in marital arguments, confrontations, and possibly even some domestic violence,” says psychology researcher Brad Bushman, who has studied the relationship between blood glucose levels and anger." ii

If you find yourself and your partner inching toward (or in the early stage of) a difficult conversation or argument, check how long it’s been since the two of you have had food or drink. It may make sense to call a brief recess for a bit of nourishment; after eating, blood sugar levels begin to rise within 15 to 30 minutes provided your meal or snack includes the proper carbohydrates.iii So nibble, then quibble.

References & Citations

i Bushman, Brad J., et al. "Low glucose relates to greater aggression in married couples." Proceedings of the National Academy of Sciences, 2014 111 (17) 6254-6257.

ii Ohio State University. "Lashing out at your spouse? Check your blood sugar." ScienceDaily, 14 April 2014.

iii “Carbohydrates from liquids, such as juices and soft drinks, are usually digested more rapidly, while carbohydrates from solid foods, such as pasta and fruits, take a bit more time to break down. Foods that don't contain carbohydrates or only very little, such as non-starchy vegetables, butter, eggs, meat, poultry, fish, cheese and nuts, do not have the ability to significantly influence your blood sugar levels.” (From: