Comparison of physical activity as an obesity-related behavior between immigrants and native-born US adults

The study addresses obesity as a major public health problem and focuses on physical activity as a key proximal determinant. Immigration has increased in the US, and prior evidence suggests immigrants often have lower obesity risk than native-born adults, despite lower income and education—a phenomenon sometimes termed the immigrant paradox. Risks for immigrants change with duration of residence, with obesity risk rising over time. Data comparing obesity-related behaviors (particularly physical activity) between immigrants and native-born adults are limited. This study’s purpose was to describe demographics, weight distribution, and specific physical activity behaviors in a nationally representative 2013 US adult sample and to estimate associations between nativity status (immigrant vs native-born) and indicators of physical activity.

Prior research indicates immigrants have lower obesity rates at entry than native-born counterparts, observed across subgroups including Latinos, Asians, and people of African descent, and despite lower socioeconomic status. Explanations include the healthy immigrant effect, social networks, and potential reporting bias. However, obesity risk among immigrants increases with length of residence; e.g., immigrants approach native-born obesity levels within 10–15 years, and Latino immigrants residing ≥15 years show markedly higher obesity risk. Studies among Puerto Rican women and a nationally representative immigrant sample corroborate the correlation between longer US residence and higher obesity risk. Obesity prevalence varies by demographic and geographic factors in the US, with influences from age, SES, education, and race/ethnicity. There is limited literature comparing immigrants and non-immigrants on proximal determinants such as physical activity; one study suggested immigrants were less likely to discuss diet and exercise with healthcare providers.

Data source: Health Information National Trends Survey (HINTS) 4, Cycle 3, a nationally representative mail survey of US adults aged ≥18, conducted September–December 2013. The survey assessed health information behaviors and multiple health-related domains including physical activity. Analyses were conducted under IRB-exempt protocols at Georgia State University. Design and measures: The primary independent variable was nativity status (immigrant vs native-born). Dependent variables were indicators of usual physical activity and BMI. Physical activity indicators included: average daily sitting time for TV/computer games/web surfing; participation in physical exercise of at least moderate intensity; and participation in muscle-strengthening exercises. Covariates: gender, age group, race/ethnicity, education level, income range, disability status, and marital status. Disability was derived from responses on sensory, mobility, self-care, errands, and emotional limitations. Statistical analysis: Univariate analyses described socio-demographics by nativity; Wald Chi-square tests compared categorical variables and t-tests compared mean age. Bivariate analyses described BMI and physical activity distributions by nativity, with p<0.05 indicating significance. Multivariate logistic regression models estimated adjusted odds ratios (AOR) and 95% confidence intervals for associations between nativity status and each physical activity indicator, adjusting for gender, age, race/ethnicity, education, marital status, and income; additional models also controlled for disability. Statistical significance was set at p<0.05. Analyses were performed using SAS 9.3.

Sample: 3,185 surveyed; 3,131 included. Females: 61%. Immigrants: 17%. Mean age: immigrants 51 (SD 15) years; native-born 55 (SD 16) years. Among immigrants: 55.3% Hispanic, 18.9% Asian, 14.7% White, 9.9% Black, 1.3% other. Education: college degree or higher—immigrants 39%, native-born 37.4%. Home ownership: immigrants 48%, native-born 69%. Immigrant residence duration: >10 years 82.6%. BMI distribution (n=3064): Obese overall 33.06%; overweight 33.78%. Immigrants: normal weight 36.27%, obese 25.65%. Native-born: obese 34.43%. Physical activity distributions (bivariate): Average daily sitting for screen/leisure <5 h: immigrants 80.41%, native-born 71.77%; 15+ h: immigrants 1.02%, native-born 1.65%. Moderate-intensity activity 1–3 times/week: immigrants 41.57%, native-born 38.34%; none: immigrants 22.61%, native-born 26.28%. Among those exercising weekly, 30–60 min/day was most common (immigrants 73.23%, native-born 76.18%). Muscle-strengthening ≥1 day/week: immigrants 46.36%, native-born 43.26%. Multivariate associations (adjusted):

• Immigrants less likely than native-born to spend ≥6 h/day in sedentary leisure (AOR 0.64; 95% CI 0.42–0.97; p=0.0350).
• Immigrants more likely to engage in at least weekly moderate-intensity activity (AOR 1.48; 95% CI 1.07–2.05; p=0.0192).
• Immigrants more likely to do muscle-strengthening ≥1 day/week, not statistically significant (AOR 1.28; 95% CI 0.98–1.67; p=0.0757). Other covariates:
• Sedentary leisure ≥6 h/day: age 65+ (AOR 1.71; 95% CI 1.16–2.52; p=0.0066) and Non-Hispanic Black (AOR 1.73; 95% CI 1.28–2.35; p=0.0004) more likely; income ≥$100k less likely (AOR 0.45; 95% CI 0.26–0.80; p=0.0061).
• Weekly moderate-intensity activity: females less likely (AOR 0.74; 95% CI 0.60–0.91; p=0.0039); education positively associated—HS/some college (AOR 1.45; 95% CI 1.02–2.05; p=0.0375), college+ (AOR 2.23; 95% CI 1.51–3.29; p<0.0001); age 65+ less likely (AOR 0.37; 95% CI 0.26–0.52; p<0.0001); Non-Hispanic Black less likely (AOR 0.67; 95% CI 0.51–0.88; p=0.0038).
• Muscle-strengthening ≥1 day/week: females less likely (AOR 0.75; 95% CI 0.63–0.89; p=0.0009); age 65+ less likely (AOR 0.52; 95% CI 0.40–0.69; p<0.0001); married/living as married less likely (AOR 0.71; 95% CI 0.59–0.85; p=0.0002); income ≥$100k more likely (AOR 1.25; 95% CI 0.89–1.77; p=0.0061). Models including disability: immigrants remained more likely to engage in weekly moderate-intensity activity (AOR 1.46; 95% CI 1.05–2.02; p=0.0242) and more likely (not significant) to do muscle-strengthening ≥1 day/week (AOR 1.266; 95% CI 0.97–1.66; p=0.0867).

Immigrants constituted roughly one-sixth of the sample and were predominantly Hispanic, aligning with national immigration patterns. Immigrants demonstrated more favorable physical activity profiles—lower sedentary leisure time and higher likelihood of weekly moderate-intensity activity—corresponding with lower obesity prevalence versus native-born adults. These behaviors may contribute to the documented lower obesity risk among immigrants at entry. Nonetheless, substantial proportions of both immigrants and native-born adults failed to meet recommended activity levels, indicating broad public health needs. The findings support targeted strategies to maintain positive behaviors among immigrants and to encourage increased physical activity across the US population, including policy and insurance incentive approaches that promote healthy lifestyles.

US immigrants exhibited healthier physical activity behaviors than native-born adults and had lower obesity prevalence in this 2013 nationally representative sample. Sustaining these behaviors among immigrants and promoting increased physical activity in the general population may reduce obesity and chronic disease risks. Future research should use prospective designs with larger samples, longitudinal follow-up from time of US entry, and matched cohorts of immigrants and native-born individuals to explore socio-demographic, economic, and cultural influences on proximal determinants of obesity and to inform targeted interventions.

The retrospective, cross-sectional nature of the survey limits causal inference and control of confounding. Acculturation effects could not be assessed due to a small number of immigrants with ≥15 years in the US, underpowering such analyses. Longitudinal outcomes cannot be evaluated. Some variables had missing data, though the authors judged the amount small and unlikely to alter findings materially.