Long-term neighborhood ethnic composition and weight-related outcomes among immigrants: The Multi-Ethnic Study of Atherosclerosis.

Weight among immigrants in the United States (US) is lower than among the US-born on average, but higher among long-term immigrants than the newly arrived. Neighborhood coethnic concentration-the proportion of neighborhood residents of the same ethnic background-may influence weight among immigrants via behavioral norms and market-driven community resources. However, the relevant exposure timeframe may be far longer than is captured by existing cross-sectional and short-term studies. Using detailed historical residential address information on 1449 older Latino and Chinese long-term immigrants, we investigated associations of 10-20-year neighborhood coethnic concentration trajectories with current waist circumference and weight-related behaviors (diet, physical activity, and sedentary time). Among Chinese participants, compared to persistent low coethnic concentration, increasing coethnic concentration was associated with higher waist circumference (difference = 1.45 cm [0.51, 2.39]). In contrast, both increasing coethnic concentration and persistent high coethnic concentration were associated with a healthier diet. Among Latino participants, trajectories characterized by higher coethnic concentration were associated with higher waist circumference (e.g., difference = 2.11 cm [0.31, 3.91] for persistent high vs. persistent low) and low physical activity. Long-term patterns of neighborhood coethnic concentration may affect weight-related outcomes among immigrants in complex ways that differ by ethnicity and outcome.