Association between length of residence and overweight among adult immigrants in Portugal: A nationwide cross-sectional study.
BACKGROUND
Despite the importance of immigrant population in Portugal few studies have analyzed the patterns of overweight/obesity in this subpopulation. The aims of this study are: (i) describe and compare the prevalence of overweight between immigrants and natives in Portugal; (ii) analyze the association between length of residence and overweight among adult immigrants in Portugal.


METHODS
A cross-sectional study (2005-2006) in a representative sample of the Portuguese population from national territory, including the Autonomous Regions of Azores and Madeira. The final sample comprised 31,685 adult participants (≥19 years old), of whom 4.6% were immigrants. Country of birth was used to determine immigrant condition. Logistic regressions were conducted to investigate the association between overweight (dependent variable) and length of residence (exposure), adjusting for all covariates in the study. A 5% confidence level and 95% CI were considered.


RESULTS
The percentage of immigrants that are overweight [44.9% (95% CI: 42.3; 47.5)] was lower than for natives [52.8% (95% CI: 52.2; 53.4)]. The migrant condition, after adjusted for sociodemographic variables, was not associated with overweight [OR 1.004 (95% CI: 0.998; 1.010)]. Among immigrants, being women [OR 0.585 (95% CI: 0.583; 0.587)], not married [OR 0.784 (95% CI: 0.781; 0.787)] and with a higher education [OR 0.481 (95% CI: 0.478; 0.483)], are probably protective factors of being overweight. Adjusting for other factors, the odds of being overweight for a long-term immigrant (≥15 years) was 1.3 times higher [OR 1.274 (95% CI: 1.250; 1.299)] than for the newcomers (<4 years).


CONCLUSIONS
The prevalence of overweight was higher for natives than immigrants. Length of residence (≥15 years) was positively associated with prevalence of overweight, among adult immigrant population. In the future, understanding dietary patterns and acculturation process may be important for health immigrant studies.
['da Costa|Liliane Peralta|LP|', 'Dias|Sónia Ferreira|SF|', 'Martins|Maria do Rosário Oliveira|MD|']
D000069:Acculturation D000328:Adult D000368:Aged D003430:Cross-Sectional Studies D054242:Emigrants and Immigrants D005260:Female D006306:Health Surveys D006801:Humans D016015:Logistic Models D008297:Male D008875:Middle Aged D009765:Obesity D050177:Overweight D011174:Portugal D015995:Prevalence D012111:Residence Characteristics D012307:Risk Factors D013997:Time Factors D055815:Young Adult
Length of residence Overweight Immigrants Portuguese population