Immigration and Obesity Among Filipinos: the Multiethnic Cohort Study

Purpose: Obesity is a growing critical health issue across race/ethnicity in the United States. Research has shown that immigration status (e.g., generational status based on birthplace and length of residence) is associated with various health outcomes among immigrants and their descendants. However, Filipino Americans have rarely been targeted in obesity research. Given that the number of Filipino immigrants is substantially increasing, it is crucial to understand the role of immigration status in the risk for obesity. This study sought to assess the association between immigration status and obesity to inform social work and public health efforts aimed at preventing and reducing obesity among Filipino Americans. 

Methods: Cross-sectional analyses were performed for ethnic Filipinos who participated in the Multiethnic Cohort Study in Hawai‘i and Los Angeles in 1993-1996. For the current study, Filipinos were selected based on self-reported ethnic/racial background that indicated 'Filipino' without any other ethnicity (n=7,818). Self-reported weight and height were used to calculate body mass index (BMI, kg/m²) and classify individuals as overweight (BMI ≥25 kg/m²) or obese (BMI ≥30 kg/m²). Filipinos were divided into Philippines-born (the first generation) and US-born (the second/third generations). Among US-born Filipinos, we defined those with both parents who were born in the Philippines as the second generation, and those with at least one US-born parent as the third generation. Philippines-born Filipinos were categorized into three groups by length of residence: ≤10 years, 11-25 years, and ≥26 years. We used the general linear model procedure with least square means for descriptive statistics (adjusting for age, gender, and education) and logistic regression to examine the associations of immigration status with being overweight or obese (additionally adjusting for physical activity and total energy intake).

Results: The prevalence of being overweight or obese was the highest in the third generation (62% and 23%, respectively), followed by the second generation (59% and 15%, respectively) and is significantly different from the first generation, Philippines-born Filipinos (around 35% and 5%, respectively). The percentage of overweight Filipino men was higher in those who had lived in the US for ≥26 years than in those with ≤25 years of residence. The multivariate odds ratios (ORs) of being overweight were 2.83 (95% confidence interval (CI): 2.40, 3.32) in the second generation and 3.20 (95% CI: 2.51, 4.08) in the third generation, compared to the Philippines-born Filipinos with ≤10 years of residence in the US. The ORs of being obese were 3.32 (95% CI: 2.46, 4.48) in the second generation and 5.54 (95% CI: 3.87, 7.95) in the third generation. Among the first generation men, those who had lived in the US for ≥26 years were 43% more likely to be overweight compared to those who had lived in the US for ≤10 years.

Implications: These findings suggest a protective effect of being Filipino-born against being overweight and being obese, and it appears to attenuate with length of residence in the US among the first generation Filipino immigrants, especially in men. Immigration status should be considered in future obesity prevention and reduction efforts.