If you've been snippy with your partner lately, you might want to reevaluate your diet. New research is investigating a potential link between a fatty diet and a stressful relationship. The study, launched in April 2012 by a husband-and-wife research team at the Ohio State University Wexler Medical Center, will look at how couples respond to discussing a stressful subject after eating a high-fat meal. Results aren't in yet, but researchers theorize that what we eat may impact how we react in heated situations.

"What you're eating may actually interact with your behaviour to make things worse in terms of your physiological response," says study researcher Janice Kiecolt-Glaser.

This theory doesn't surprise Cassie Reid, a registered dietitian at Cleveland Clinic Canada in Toronto who often advises couples on healthy eating habits. "If you have a diet that's low in protein and higher in processed carbohydrates, it can lead to feeling unsatisfied and irritated, and that can happen on a hormonal level," she explains.

Here's how it works: everything we eat breaks down into glucose, which is what the body uses for energy. Once glucose enters the body, the pancreas releases the hormone insulin to convert it to usable energy or store it for later. But a diet that's high in fat and processed carbs may make it harder for the insulin to move that glucose into the cells that need it. The body may then release more insulin, which can make you feel hungry and irritated. "We all know that when you give in and eat something that makes you feel gross, you can take it out on the people around you."

On the flip side, Reid says choosing to eat well can be a bonding experience for couples and may improve relationships. She recommends making healthy living a team effort by exercising and cooking together.

Not sure you can convince your partner to hop on the healthy bandwagon? Lead by example and start making healthy choices on your own. "Be strong about it and make it clear to your partner that this is the way you'd like to eat," suggests Reid.

Photography, iStockphoto.com.