将于下月发表在《肥胖》期刊上的一项最新研究发现，结婚或同居的两个人长胖的几率是同龄独居者的两倍。研究人员表示，结婚会给生活带来很多积极的变化，比如吸烟人数减少、死亡率降低等；但同时人们的肥胖几率却有所增加。研究发现，共同生活超过两年的伴侣会表现出相似的行为举止和肥胖状况。两个人生活在一起后，生活习惯的改变和互相适应可能是导致肥胖的主要原因。

Couples who live together are more than twice as likely to become obese¹ than those who live separately, new research shows.

The study to be published next month in the journal² Obesity³ also showed that the risk of obesity rises the longer people live together.

Penny Gordon-Larsen, associate professor of nutrition at the University of North Carolina, found some positive health benefits to marriage, including decreased cigarette smoking and lower mortality.

But she added: "We also see greater weight gain than in others of the same age, and greater risk of obesity.

"Maybe the cause of weight gain is not just age, but the pressure of shifting⁴ behaviours that result in weight gain."

She said people living together – married or not – tended to eat meals together, possibly cooking bigger meals or eating out more often than they did when they were single.

They were more likely to watch television together instead of going to the gym or playing a sport. Her research found that couples who lived together for more than two years – especially those who were married – were most likely to display similar obesity patterns and physical behaviours.

She added: "Maybe this a good time to intervene⁵ with these young couples and get them to have a more positive effect on each other.

"Couples can use that phenomenon to their advantage if they're aware of what's going on." "They can be good influences on each other. That may be how they can avoid the extra pounds now associated with marriage."