Immigrants generally originate from countries where the prevalence of obesity is lower than that of the United States, but acculturation to U.S. norms over time may lead to an increasing prevalence of obesity among this population, said the study's lead author Mita Sanghavi Goel, M.D., a researcher in general internal medicine at Northwestern University Feinberg School of Medicine.
Immigrants also face more barriers to quality health care and are less likely to receive preventive health care than persons born in the United States, Goel said.
Goel and co-researchers from Harvard University also found that immigrants are less likely than U.S.-born people to discuss diet and exercise with their doctors.
Over 127 million American adults are overweight and almost 70 million are obese or severely obese. The high prevalence of obesity in the U.S. population has produced a major burden of obesity-related illness and death.
Immigrants are the fastest growing segment of Americans, comprising more than 11 percent of the total U.S. population.
The investigators surveyed almost 32,400 eligible people. About 14 percent were foreign born and generally older and had lower annual household incomes; less education; lower illness burden; and less access to good health care than U.S.-born respondents.
Fewer of the foreign-born respondents were obese compared with respondents born in the United States, but they were more sedentary than U.S.-born respondents.
The proportion of overweight and obese foreign-born individuals increased with longer residence in the United States.