The weight of US residence among immigrants: a systematic review.

As the number of immigrants in the USA continues to rise, it becomes increasingly important to understand how their health differs from native-born individuals. Obesity is a public health concern and a component of health that may differ and change in important ways in immigrants. This research synthesizes the current literature on the relationship between immigrant duration of residence in the USA and body weight. Five databases from the health and social sciences were searched for all pertinent publications. Fifteen articles met inclusion criteria, 14 of which reported a significant, positive relationship between body mass index and duration of residence in the USA (all P-values <0.10). Two studies reported a threshold effect of weight gain after 10 years of US residence, and another study reported that body mass index peaks after 21 years of duration for men and after 15 years for women. The results of this review suggest that weight gain prevention programmes would be beneficial for many immigrants within the first decade of residence in the USA. Prevention efforts may be more successful if nativity and acculturation are considered in addition to race/ethnicity. Future research is needed to identify the specific mechanisms through which living in the USA may adversely affect health outcomes.