Being in a happy, high-quality marriage may help prevent obesity by influencing the connection between the brain and the gut.
A world-first study on how social bonds influence weight and eating behaviors through “the love hormone” oxytocin has suggested that the quality of a person’s relationships may be as important to physical health as eating well and exercising.
Researchers studied almost 100 people with a range of marital statuses, body mass index, race, age, sex, diets and economic statuses—analysing images of the subjects’ brains while they looked at pictures of food. They also took samples of body fluids and conducted clinical and behavioral evaluations, including on how they felt about their emotional support system.
It found that married people with higher perceived emotional support had a lower body mass index and exhibited fewer food addiction behaviors compared to married people with low emotional support.
People with higher emotional support showed more activity in the part of the brain that manages craving and appetite when viewing food images, but unmarried people–regardless of whether they had strong emotional support–did not show the same brain patterns. Researchers believe this could be due to their more diverse and less consistent social support networks, rather than a spouse who is always there.
This also affected gut metabolism: married participants with strong emotional support had higher levels of oxytocin compared to unmarried individuals, which may suggest oxytocin acts as a messenger that enhances self-control and promotes healthier gut metabolic profiles.
However, further and more long-term research with larger and more diverse samples are required to confirm the findings of the study. The researchers noted that it was carried out at a single point in time, most participants were overweight or obese, and married participants tended to be older.
Dr Arpana Church, a neuroscientist at UCLA Health and lead author of the study, said the study reveals how “marriage and emotional support literally get ‘under the skin’ to influence obesity risk.”
In a statement, she added that oxytocin could be thought of as a “conductor orchestrating a symphony between the brain and gut,” which “strengthens the brain’s ability to resist food cravings while promoting beneficial metabolic processes in the gut, both of which help maintain healthy weight.”
The results of the study could indicate that marriage serves as a “training ground for self-control,” as maintaining a long-term partnership needs a person to override “destructive impulses” and work towards long-term goals, “which may strengthen the same brain circuits involved in managing eating behavior.”
It was vital, she said, to understand the importance of building “long-lasting, positive, and stable relationships to promote overall health.
“Social connections aren’t just emotionally fulfilling; they’re biologically embedded in our health.”
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Reference
Zhang, X., Dong, T. S., Gee, G. C., Kilpatrick, L. A., Beltran-Sanchez, H., Wang, M. C., Vaughan, A., & Church, A. (2025). Social bonds and health: Exploring the impact of social relations on oxytocin and brain–gut communication in shaping obesity. Gut Microbes, 17(1). https://doi.org/10.1080/19490976.2025.2566978
