02/14/2011 12:39 pm ET | Updated May 25, 2011

And They Lived Pudgily Ever After: Dating, Marriage and Obesity

When you sit down with your sweetheart at your favorite restaurant to share a bottle of wine and chocolate molten lava cake this Valentine's Day, look closely. Are either of you putting on some poundage? Depending on how long you've been in your relationship, there's a good chance those love handles came from being in love. According to a study published in the July 2009 issue of Obesity, married people are more likely to become obese than those who are single.

Two nutrition epidemiologists from the University of North Carolina at Chapel Hill set out to investigate whether romantic partnership and duration of cohabitation are related to incident obesity and obesity-promoting behaviors. The researchers studied two groups of people for this. One part of the study followed a large group teenagers as they grew into young adulthood and the other part studied 1,293 couples.

In a phone interview, one of the lead authors, Penny Gordon-Larsen, PhD, Associate Professor of Nutrition at the Gillings School of Global Public Health told me that over the years the study was conducted, everybody gained weight, as is common in our society these days. But, hands down, the people who gained the most weight were the couples who had been together the longest. The ones who stayed the thinnest were the ones who were still living la vida solo. Although much of the information is convoluted and difficult to explain, Gordon-Larsen says, "there is a higher concordance in obesity and obesity related behavior in married couples versus dating couples." And, cohabitating couples fall somewhere in between. The $64,000 question: Does the environment of living together and adopting each other's bad habits cause the weight gain or is "assortative mating" (attracting a partner of a similar body type or traits to your own) to blame? This is what Gordon-Larsen would have liked to vet from the study but couldn't.

Before you toss your engagement ring back to your fiancé, or pull your profile off of eHarmony, consider this. The same bad behavior that you may have adopted from your honey, like making multiple laps around the neighborhood Hometown Buffet or watching a House marathon on cable, can also be turned around with positive support and teamwork with your spouse. It's usually much harder to stick to a weight loss program when you have to go at it alone. Your willpower can be worn down when you have your partner eating Ben & Jerry's in front of you or lounging on the sofa after work when you're trying to make it to the gym. Support from the one you love on the other hand, has a very positive effect on your efforts.

So instead of a decadent dinner and romantic comedy flick on Valentine's Day, try these healthy and still romantic alternatives instead:
-A hike in the Santa Monica mountains followed by brunch along the beach.
-A walk thru Huntington Library and around the Botanical Gardens then a sashimi dinner at your favorite sushi place.
-Go for a tandem bike ride along the beach and pack a picnic.
-Take a boot camp class or book a trainer for a kick-butt workout followed by a couple's massage at a spa.

Gordon-Larsen says make dates to workout rather than eat out. After all, sweating together is definitely sexy!

If you've gained weight during a relationship or lost weight together, post a comment and share your experience.