People who come to the United States from other countries tend to be as obese as U.S. natives after 15 years, according to an article in the December 15 issue of JAMA (2004; 292 (23), 2860–67).

Investigators looked at data from the 2000 National Health Interview Survey. Of 32,374 eligible people, about 14% were immigrants. When these foreign-born persons had lived in the United States for less than a year, only 8% of them were obese. In contrast, after they had been living in the United States for at least 15 years, their BMI statistics approached those of U.S. natives. Among the foreign-born persons, 41% were at normal weight, 38% were overweight and 19% were obese—compared with (respectively) 41%, 35% and 22% of the U.S.-born respondents.

The authors concluded that, as more people move to the United States from other countries, it may be necessary to offer diet and exercise intervention programs early in order to prevent weight gain and, consequently, obesity-related illnesses.