Is Your Significant Other Making You Fat?

In the study, which included more than 6,000 Australian women, scientists found the average 10-year weight gain for a 140-pound woman was 20 pounds if she had a live-in partner and a child, and 15 pounds if she had a partner but no kids. Women without a significant other or little ones? They only put on 11 pounds, The New York Times reported.

The suspected causes of this weight gain disparity are behavioral changes for those women don't have children and psychological changes for those who do, according to the study's lead author, Annette J. Dobson, a professor of biostatistics at the University of Queensland in Australia.

"Women's bodies may adjust to the increased weight associated with having a baby," Dobson told The New York Times. "There may be a metabolic adjustment that goes on when women are pregnant that is hard to reverse. This would be more consistent with our findings than any other explanation."

Even after adjusting factors for age, height, education, employment and exercise, married women still outweighed their single counterparts. This left some scientists scratching their heads, but Maureen A. Murtaugh, an associate professor of epidemiology at the University of Utah thinks the answer could lie in busier social lives that married women tend to have.

"Think of going to a restaurant," Murtaugh told The New York Times. "They serve a 6-foot man the same amount as they serve me, even though I'm 5-feet, 5-inches and 60 pounds lighter."

Also, for those wondering about the effects of marriage on men, an earlier study cited an increased risk for obesity in men with children, further pointing to the theory that social factors -- not biological ones -- lead to packing on the pounds over time.

Whatever the reason, the fact remains that marriage and children may contribute to weight gain. So turning off the TV, eating right, exercising and staying active as a family are the things that might just help you live happily -- and healthily -- ever after.

Take a look at other reasons why marriage could make you fat.