Maintaining good health usually implies ample exercise, eating well and avoiding hazardous activities like going to the beach without sunscreen.

Most of us, however, don’t think of marriage.

A recent study by University of California, Los Angeles scientists suggests that feeling lonely and unsupported in a marriage exacts not just an emotional toll, but a physical one.

Their study found that the body mass index of these lonely spouses was five points higher than those who felt supported and comforted in their marriage.

The investigation analyzed brain imaging, gut metabolites and blood tests to measure oxytocin in 94 Los Angeles adults. Participants also completed a questionnaire on their emotional support system.

The research results didn’t hold for unmarried individuals, whose weight did not appear to be affected by the dynamic.

One potential factor in the weight gain appears to be food addiction. Scientists could actually see differences in brain activity during an MRI, depending on a person’s relationship quality, when participants were shown a photo of food.

The part of the brain where these changes occur is called the dorsolateral prefrontal cortex. This is an area of the brain where impulse control is centered. If this area of the brain goes awry, consequences might include obesity, depression and chronic pain.

Researchers say a good marriage involves self-control. Spouses suppress selfish motivations to support their partner’s needs. If that mutual support is missing, those self-control circuits atrophy.

A bad marriage can weigh on a spouse in more ways than one.