Living together or being married might have some health benefits, but losing weight may not be one of them.
Couples who marry or cohabit are more likely than their single-and-dating counterparts to be obese, according to a new study in the July issue of the journal Obesity. Those living together for two years or more are also less apt to be physically active, part of the recipe for obesity.
Researchers from the University of North Carolina at Chapel Hill looked at data from the National Longitudinal Study of Adolescent Health, a large study tracking students from Grade 7 through adulthood to age 27. The data also included a couples sample, which included the study participants' heterosexual romantic partners.
Here's the breakdown of their romantic life: about 41% transitioned from single-and-dating to dating, 29% transitioned to single, 17% transitioned to living with someone, and 13% transitioned to marriage. Men and women who shifted from single-and-dating to married were more likely to become obese than those who made the transition from single-and-dating to dating. And women who went from single-and-dating to single, or single-and-dating to cohabiting, were more likely to become obese.
Living with a romantic partner for one year or more increased women's chances of becoming obese. Men who lived with a romantic partner for one to two years were twice as likely to become obese compared to men not living with a significant other.
Marriage didn't seem to have much of a slimming effect. Overall, couples who lived together or were married had less healthy habits for obesity, exercise and screen time than dating couples. Married couples also tended to have one or two fewer active partners in them than those who were dating, and cohabiting couples were more likely to have two sedentary partners in them. Couples who lived together for two years or more were considerably more likely to have one or two partners in them who were obese, less physically active, and more sedentary.
As for the whys of all this, researchers speculate that a couple's living conditions may contribute to the added poundage. The actions of one partner -- eating fattier foods, for example -- could influence the other, perhaps with bad results. But knowing that, they add, may also lead to more effective interventions.
So maybe registering for a Wii Fit for your wedding isn't such a bad idea after all.
-- Jeannine Stein
Photo: Ken Hively / Los Angeles Times