Background: Non-communicable diseases and chronic conditions continue to emerge as public health crises in the United States (U.S.) and globally. Obesity, one of the most notable of such conditions, is associated with significant morbidity and mortality. Compared to non-immigrants, U.S. immigrants are known to have lower risks of obesity. However, there is paucity of literature on how U.S. immigrants compare to native-born adults regarding obesity-related behavior. Objective: We aim to describe demographic characteristics, weight distribution, and distributions of specific obesity-related behaviors among immigrant and native-born U.S. adults. Secondarily, we aim to estimate associations between nativity status and obesity-related behavior among U.S. adults. Methodology: We analyzed data from the Health Information National Trends Survey conducted between September and December 2013 (HINTS 4 Cycle 3). The independent variable was nativity status (immigrant vs. native-born). Outcomes of interest were indicators of dietary behavior (fruit, vegetable, and soda intake) and indicators of physical activity level (sitting time spent on television/computer games/web surfing, participation in physical exercise, and participation in muscle training exercise). Bivariate analyses and multivariable logistic regression models were utilized in describing demographics, weight distribution, and associations between variables of interest. Statistical significance was determined using p-values < 0.05 and 95% CI around adjusted odds ratios. Results: A total of 3185 individuals participated in the survey. The overall male to female ratio was 1:1.6. Approximately 17% of participants were immigrants and roughly 83% were native-born U.S. adults. The mean age was 51 years (SD +/- 15) for immigrants and 55 years (SD+/-16) for native-born respondents. Among immigrants, the racial distribution was 55.3% Hispanic, 18.9% Asian, 14.7% White, 9.9% Black and 1.3% other races. About 25% of immigrants were obese, compared to 34% of non-immigrants. Immigrants were more likely than native-born respondents to take some quantity of fruit daily (adjusted OR = 1.88; 95% CI: 1.07 - 3.32; p = 0.0290); and less likely than native-born respondents to consume soda every week (adjusted OR = 0.74; 95% CI: 0.55 - 0.98; p = 0.0383). Immigrants were less likely than non-immigrants to spend 6 hours or more a day on sedentary leisure activities (adjusted OR = 0.64; 95% CI: 0.42 - 0.97; p = 0.0350). Immigrants were also more likely than non-immigrants to engage in physical activity of at least moderate intensity, at least once a week (adjusted OR = 1.48; 95% CI: 1.07 - 2.05; p = 0.0192). Conclusion: Compared to non-immigrants, U.S. immigrants appear to have a tendency towards healthier lifestyles regarding diet and physical activity behavior. Strategies to sustain such tendencies among immigrants will promote health and reduce risks of obesity, cancer and other chronic diseases in the U.S. More robust studies are needed to shed more light on various socio-economic, cultural and demographic factors that influence proximal determinants of obesity.