A new study is providing fresh evidence that American dietary habits are not good for the waistline. A report published in the Journal of the American Medical Association reveals that immigrants who have been in the United States for a number of years are fatter than those who recently arrived.
As Americans have become larger -- and the negative health effects of obesity have become more apparent -- U.S. medical researchers have turned their attention to the topic of why people are fat. So far, most studies have considered only the native-born population.
But Mita Sanghavi Goel, a medical professor at Chicago's Northwestern University, decided to conduct a study of obesity among immigrants - partly after observing her own family. "My parents are immigrants," she says, "and when I looked at their wedding pictures and then looked at them, I sort of wondered, 'Something has changed.' That might be true in many, many families, but I thought about that in the context of an immigrant lifestyle in the United States."
She discovered that obesity is not a major problem among newly arrived immigrants - just 8% are obese, compared with 22% of native-born Americans. But, after a number of years, the immigrant population starts to look a lot more like the native-born. Dr. Goel found that, among immigrants who have been in the United States for 15 years or more, the obesity rate was 19% -- nearly as high as the rate in the native population. "We found that this was true for foreign-born whites, foreign-born Latinos, and foreign-born Asians," says Dr. Goel. "We didn't see this association for foreign-born blacks, and it could be we just didn't have a large number of foreign-born blacks in our population."
So what is causing the increase in obesity? Dr. Goel's study did not attempt to answer that question. But she and others in the medical community say it is not too difficult to figure out. There is a lot of food to be had in the United States, and much of it is processed and full of fat and sugar. "As people move to this country, there are certain foods that are more readily available," says Alan Tso, a physician who works with immigrants at the Charles B. Wang Community Health Center in New York City's Chinatown. "It's very different from some of the villages in China. And so meat is more readily available and so on and so forth. So a lot of immigrants, [when] they come over, they change their diet."
They also change the way they eat, according to Xiao bin Li, an immigrant who has been living in the United States for almost 15 years. Ms. Li says that, in China, most people eat their main meal in the middle of the day and then have a light dinner before going to bed. But in America, people are working too much during the day to eat a major meal. "So that's why [you] eat just a small lunch," says Ms. Li. "But after a whole day of work, when you go home, you want a big dinner. After dinner, you only lie down, then sleep. No exercise."
It is not clear whether immigrant communities recognize excess weight as a problem. Researcher Mita Goel says very few immigrants visit a doctor about their weight. According to Dr. Alan Tso, this may be because of cultural misconceptions about putting on extra kilos. "Again, it goes back to economics, basically," says Dr. Tso. "People who are more well-off, in China, at least, in the old days, you know they have a rounder face, because they eat better, right? That's the symbol of wealth."
Dr. Tso says this misconception is having an impact on children. He recently completed s study of more than 300 children, all born to immigrants living in the United States. He found that the youngsters were more likely to be obese if they were been born after their parents had arrived in America.