You know that breakups can affect your weight—either for the better (more time for the gym!) or the worse (oh hai, Ben & Jerry's). But did you know that relationship issues can cause weight gain even if you're in a committed relationship? (Learn about the other weird ways your body reacts to stress.)
For four years, University of Michigan researchers followed more than 2,000 heterosexual married people who were together for an average of 34 years and had them record their waist circumference, negative marriage quality, stress level, and more. They found that the more stressed the man felt about the state of his relationship, the more weight both he and his wife gained—up to four extra inches on their waists over the course of the study. (Weirdly enough, when women had fewer relationship complaints, the husbands were more likely to gain weight. Researchers think this might be because it implies the woman doesn't care.)
"Marriage has powerful influences on health," lead author Kira Birditt, Ph.D., a research associate professor at the University of Michigan Institute for Social Research said in a press release. "The stress experienced by partners, and not the individual's stress, was associated with increased waist circumference. This effect of stress was even stronger in particular spousal relationships."
And don't think that just because you haven't been married for three decades that your young love will protect you. Birditt says the effects of partner stress are the same for younger couples, although she notes you might not feel the health effects as keenly as older couples. (But once you've gained that weight, those increased levels of body fat can actually trigger a vicious stress-weight gain cycle.)
No matter what the reason, however, the message is clear: Relationship stress affects both partners, so both of you need to take an active role in managing it. "It's important for couples to find ways to cope together using positive coping strategies like exercising together, having calm discussions, and creating shared goals," she says.