It's full-on wedding season, but anyone about to pledge to have and to hold should pay closer attention to the bit about "in sickness and in health." New research shows that within a few short years of getting hitched, married individuals are twice as likely to become obese as are people who are merely dating.
The study, published in the July issue of Obesity, set out to determine how romantic relationships affect the tell-no-lies number on the scale. Researchers tracked changes over a handful of years in the weight and relationship status of 6,949 individuals, and their findings don't bode well for commitment. Not only are married people more likely to become obese than those who are just dating, but young people who move in with a boyfriend or girlfriend tend to pack on the pounds too.
And in a twist sure to tick off all the ladies in the house, the study notes that unmarried women who have been living with their sweeties for five years or less run a 63% increased risk of obesity. What about unmarried men? On average, they have no increased risk during cohabitation.
"With women, we saw incremental risk after one year," says Penny Gordon-Larsen, one of the two nutrition epidemiologists at the University of North Carolina at Chapel Hill (UNC) who conducted the study. "The longer she lived with a romantic partner, the more likely she was to keep putting on weight." Meanwhile, the risk of obesity among guys married and unmarried spikes only between the first and second years of living together.
What's behind the weight gain? Gordon-Larsen and the paper's lead author, Natalie The, have their theories after questioning 1,293 couples for a separate part of the study. Mealtime may become more important than it was when the people were living alone. Gym memberships may not get the same workouts they did before nuptials. And maybe, after months of prepping to squeeze into crinolined and cummerbunded finery, couples just let themselves go.
Scientists have known for a while that having a close relationship with an obese person, whether a friend or a spouse, makes you more likely to become obese. So how to break the cycle? Perhaps by drawing inspiration from the same person who helped get you into this mess: your better half. Amy Gorin, an assistant professor of psychology at the University of Connecticut, published a study last year that showed if one spouse participates in a weight-loss program, the unenrolled spouse tends to lose about 5 lb. Now Gorin is exploring whether enlisting the support of spouses can help both partners shed more pounds. In June she wrapped up a 16-week pilot study of 20 couples, in one of which, the support person lost more weight than the main participant in the study.
Couples don't have to live chubbily ever after. And studies show that marriage conveys some health benefits, like living longer and being more likely to quit smoking, notes UNC's The, who lives with her boyfriend but insists her obesity findings haven't scared her away from the idea of marriage. "This is an interesting paradox," she says, "but it certainly wouldn't stop me."