That is the finding of a study on marital satisfaction and weight gain, according to psychologist Andrea L. Meltzer, lead researcher and an assistant professor in the SMU Department of Psychology at Southern Methodist University in Dallas.
"On average, spouses who were more satisfied with their marriage were less likely to consider leaving their marriage, and they gained more weight over time," Meltzer said.
"In contrast, couples who were less satisfied in their relationship tended to gain less weight over time," she said.
The study's researchers said the findings challenge the long-held notion that quality relationships are always beneficial to one's health.
Instead, they said, the findings suggest that spouses who are satisfied in the marriage are less motivated to attract an alternative mate.
As a result, satisfied spouses relax efforts to maintain their weight.
Previous psychological research has established that marriage is associated with weight gain and that divorce is associated with weight loss.
But the role of marital satisfaction in those changes in weight is less clear, Meltzer said.
Previous research also has demonstrated that marital satisfaction is associated with health maintenance behaviors, she said.
"For example, studies have found that satisfied couples are more likely to take medications on time and schedule annual physicals," Meltzer said.
The study is published online in the scientific journal Health Psychology.