In the study, men and women with a history of depression whose arguments with spouses were especially heated showed several potential metabolic problems after eating a high-fat meal.
They burned fewer calories and had higher levels of insulin and spikes of triglycerides - a form of fat in the blood - after eating a heavy meal when compared to participants without these risk factors.
The reduced calorie-burning in the seven hours after a single meal - 118 fewer calories, on average, by previously depressed people with marital discord - translates to weight gain of up to 12 pounds in a year, researchers found.
"These findings not only identify how chronic stressors can lead to obesity, but also point to how important it is to treat mood disorders. Interventions for mental health clearly could benefit physical health as well," said Jan Kiecolt-Glaser, director of the Institute for Behavioural Medicine Research at The Ohio State University and lead author of the study.
"Our results probably underestimate the health risks because the effects of only one meal were analysed. Most people eat every four to five hours, and often dine with their spouses," said Kiecolt-Glaser, also a professor of psychiatry and psychology.