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When I got married seven years ago, my best friend took bets on how much weight I’d gain. She figured at least 10 pounds within five years. After all this time, I’m proud to say that I still weigh less than when my husband and I said our “I dos”— but it hasn’t been easy. Being a dietitian definitely helps, but being married to someone who eats healthy and exercises also makes it easier for me to keep the scale steady.

For most women, marriage is good for your overall health—just not your waistline. Living with a man (married or not) leads to significant pounds gained, and the longer you’re together, the worse it can get. (Have you seen Mariah Carey lately?) Now, researchers at the University of North Carolina are trying to figure out why women gain so much once they live with, or marry, a man.

The researchers reported their findings in the prestigious journal Obesity this month, after studying nearly 1,300 couples. They found that when single women become part of a couple, their risk of becoming obese doubles or triples. While men also put on pounds, women gain appreciably more than their romantic partners.

The authors outlined several reasons why we gain once we say our I dos. Here’s just the short list: You no longer care as much about attracting a mate so you let yourself go—you settle. Women eat larger portions and eat more frequently to match their man’s appetite. Couples engage in less physical activity than they did when they were single and watch more TV instead. In essence, couples create their own unhealthy “obesigenic” environment in which it is safe for each to eat what he or she wants and be inactive.

Sad, but true—I can certainly relate to a lot of that myself.

But you don’t have to succumb to extra love handles once you find yourself in love—even if your partner isn't the picture of health himself. Here are some tips to keep both of your waistlines in bachelor and bachelorette shape.

Next page: Pretend you're single

Pretend you’re single
I do this often, just to wonder if I would be attractive to other men. It gives me a realistic view of whether I’m sticking to my workout routine or if I’ve gained a few pounds. I have a closet full of skinny jeans that I make sure I wear at least once a month to make sure they still fit.

Feed yourself first
Many married women just cook what their spouse loves—and often it’s loaded with too many calories and fat. Instead, make something that is good for you—a salad or grilled seafood—and then figure out what side dishes you can add for your man (but skip for yourself).

Set healthy house rules
To break your home from being a toxic food environment, take charge of the shopping and set ground rules for what can (and cannot) come in your kitchen. Keep it well stocked with healthy fruits, vegetables, and whole grains. Take a healthy cooking course if you need to brush up on some leaner cooking techniques. Also, limit the hours spent watching TV and try to schedule more active time with your partner, instead of couch time.

Address the issues
If you’re unhappy in your relationship (or with work, friends, or with any other situation) and you’re overeating to feel better, you’re never going to feel good: There isn’t enough chocolate in the world to heal our emotional ups and downs. Seek a counselor or trusted friend, or find another outlet to help you deal with your emotions.