The weight of US residence among immigrants: a systematic review

Abstract

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.

The impact of migration on body weight: a review

“…However, BMI tends to increase as the length of residence in the host country increases, progressively converging towards the levels of the American population 7 . The same phenomenon has been observed by studies in Canada, Australia and Europe 8 .…”

“…The flux of immigrants has changed since 2007 and this is an important factor to consider when analysing and interpreting data. Notwithstanding the methodological differences, the most relevant conclusion of these studies is that there is a significant and positive relationship between body weight and length of residence among U.S. immigrants 8 . This association varies according to ethnic background and may be weaker or inexistent among immigrants with a higher level of education 78 , and BMI tends to converge towards the levels of the host population at a quicker rate among women immigrants 79 .…”

“…This phenomenon is known as the "healthy immigrant effect" 7 . However, this effect often disappears as length of residence increases 7,8 . On the other hand, comparative studies show that after immigration the risk of diseases associated with obesity, such as cardiovascular disease, diabetes, and cancer, may change over time 7 .…”

“…New immigrants often have lower socioeconomic status and work longer hours than nonimmigrants, which reduces the amount of time available and opportunities to practice physical activity 49 . Nevertheless, some immigrants state being more physically active after immigration 8 .…”

“…Women are generally considered more vulnerable to the acculturation process than men and consequently are more susceptible to being overweight than men 8 . It is also important to study morbidity differences according to gender, ethnic background and age 61,62 .…”