Penny Gordon-Larsen, Ph.D., an associate professor of nutrition, and Natalie The, a nutrition doctoral student, both with the UNC Gillings School of Global Public Health, found people face the following risks of becoming obese, compared to people in romantic relationships who are not living together: married women and men – both more than twice as likely to become obese, women living with a romantic partner – 63 percent increased risk, men living with a romantic partner – no increased risk.
The findings will be published next month in the journal Obesity.
“We’re trying to find out some of the reasons why this might be happening,” He said.
“There are a number of health benefits to marriage, including decreased cigarette smoking and lower mortality. But we also see greater weight gain than in others of the same age, and greater risk of obesity,” she added.
“A number of studies have shown that teens tend to put on weight as they become young adults,” Gordon-Larsen said. “This is a time when people are facing significant changes in their lives. Marriage and cohabitation present even bigger changes than single people face. Maybe the cause of weight gain is not just age, but the pressure of shifting behaviors that result in weight gain.”
According to Gordon-Larsen, when people are living together – married or not – they tend to share behaviors and activity patterns. They may chose to eat meals together, possibly cooking bigger meals or eating out more often than they did when they were single, and may watch TV together instead of going to the gym or playing a sport.
Gordon-Larsen said that in subsequent interviews with both romantic partners, they found that couples who lived together for more than two years (especially those who were married) were most likely to display similar weight/obesity patterns and physical activity behaviors.
“If this is a time of shifting behaviors, and of influencing each other, then maybe it’s a good time to intervene with these young couples and get them to have a more positive effect on each other,” Gordon-Larsen said. “Maybe they can exercise together or cook healthy meals together. People who are married or who are living together tend to share behaviors. Couples can use that phenomenon to their advantage if they’re aware of what’s going on.”
“When people are married, or living together, they can offer each other social support for healthy behaviors and a healthy environment,” Gordon-Larsen said. “They can be good influences on each other. That may be how they can avoid the extra pounds now associated with marriage.”