Obesity among US immigrant subgroups by duration of residence

Context The prevalence of obesity has increased substantially since the 1980s. While immigrants are the fastest growing segment of the US population, little is known about obesity or clinician counseling about diet and exercise in this group. Objectives To estimate the prevalence of obesity among immigrant subgroups and quantify the magnitude of the association with duration of US residence, and to describe reported diet and exercise counseling by birthplace, race, and ethnicity. Design, Setting, and Participants Cross-sectional study using data from the 2000 National Health Interview Survey. Main Outcome Measures Body mass index (BMI, measured as weight in kilograms divided by the square of height in meters) based on self-reported height and weight measurements, and self-reported rates of diet and exercise counseling. Results Of 32374 respondents, 14% were immigrants. The prevalence of obesity was 16% among immigrants and 22% among US-born individuals. The age- and sex-adjusted prevalence of obesity was 8% among immigrants living in the United States for less than 1 year, but 19% among those living in the United States for at least 15 years. After adjusting forage, sociodemographic, and lifestyle factors, living in the United States for 10 to 15 and at least 15 years was associated with BMI increases of 0.88 and 1.39, respectively. The association for 15 years or more was significant for all immigrant subgroups except foreign-born blacks. Additionally, immigrants were less likely than US-born individuals to report discussing diet and exercise with clinicians (18% vs 24%, P<.001; 19% vs 23%, P<.001, respectively). These differences were not accounted for by sociodemographic characteristics, illness burden, BMI, or access to care among some subgroups of immigrants. Conclusions Among different immigrant subgroups, number of years of residence in the United States is associated with higher BMI beginning after 10 years. The prevalence of obesity among immigrants living in the United States for at least 15 years approached that of US-born adults. Early intervention with diet and physical activity may represent an opportunity to prevent weight gain, obesity, and obesity-related chronic illnesses.