In the perfect fairytale world, we'd get married to our Prince Charming and live happily ever after. But in real life, well, we start to sprout love handles (no pun intended) as the extra pounds creep on -- slowly, but surely.

An increasing number of research has found a connection between married couples and weight gain. Newlywed women in their early 20s packed on 24 pounds while newly married men gained 30 pounds -- an average of 6 to 9 pounds more than their peers who are single and dating, according to a study by the Obesity Society.

But why the post-marriage weight gain? Getting too comfy with your spouse may be to blame: It's the "I-don't-have-to-take-care-of-myself-anymore" attitude many men and women adopt after they exchange their wedding vows and the loss of motivation to stay thin. (In a single world, we have to aim to look our best to the opposite sex and oftentimes that includes having a healthy weight.)

Another culprit for the weight gain is a shared living environment. Eating habits are socially contagious and you're more likely to influence each other's diet when you're living together. That means when one partner falls into a routine of making unhealthy choices, the other is likely to follow suit. (Think late-night TV and your mate orders a pizza. Guess who shares a slice or two with him!)

But the good news is that you can make this shared environment work to your advantage. Start embarking on an active lifestyle and your healthy habits will rub off on your spouse. And there is also evidence that couples who join forces to shed the pounds are more successful than those who go at it alone. Here are some healthy ideas for you and your guy:

Split the calories

Sharing an entree or dessert cuts the calories in half, not to mention you'll save money, too. The next time you're eating out, try ordering a shared meal with extra greens on the side.

Discover enjoyable activities

There are much more exciting ways to spend time together than in front of the TV. Get moving -- whether it's signing up for salsa classes, rollerblading or biking together. The key is to find an activity you both enjoy so you're more likely to stick to it.

Be each other's gym buddy

Many people find working it out solo at the gym a bore. But sweating it out together makes you more motivated and less likely to find exercising monotonous.

Compete

Rev up your weight-loss motivation by engaging in a little healthy competition! For example, "whoever completes a 3-hour run this week doesn't have to do the dishes."