英语翻译

英语翻译
标题是：find yourself packing it on?blame friends
文章是：Obesity can spread from person to person,much like a virus,researchers are reporting today.When one person gains weight,close friends tend to gain weight,too.
Their study,published in The New England Journal of Medicine,involved a detailed analysis of a large social network of 12,067 people who had been closely followed for 32 years,from 1971 to 2003.
The investigators knew who was friends with whom as well as who was a spouse or sibling or neighbor,and they knew how much each person weighed at various times over three decades.1 That let them reconstruct2 what happened over the years as individuals became obese.Did their friends also become obese?Did family members?Or neighbors?
The answer,the researchers report,was that people were most likely to become obese when a friend became obese.That increased a person’s chances of becoming obese by 57 percent.3 There was no effect when a neighbor gained or lost weight4,however,and family members had less influence than friends.It did not even matter if the friend was hundreds of miles away,the influence remained.5And the greatest influence of all was between close mutual friends.There,if one became obese,the other had a 171 percent increased chance of becoming obese,too.
The same effect seemed tO occur for weight loss,the investigators say.But since most people were gaining,not losing,over the 32 years,the result was,on average,that people grew fatter.
Dr.Nicholas A.Christakis,a physician and professor of medical sociology at Harvard Medical School and a principal investigator in the new study,said one explanation was that friends affected each others’ perception of fatness6.When a close friend becomes obese,obesity may not look so bad.
“You change your idea of what is an acceptable body type by looking at the people around you,”Dr.Christakis said.
The investigators say their findings can help explain why Americans have become fatter in recent years—each person who became obese was likely to drag along some friends.