The immigration effect on obesity and overweight in Israeli Jewish male adolescents born 1970–1993

PurposeThe aim of the study was to assess the relationship between age of arrival of male pediatric immigrant populations in Israel and their risk for subsequent high-weight morbidity at adolescence.MethodsThe study analyzed a pooled cross section of 89,744 foreign-born male Jewish study participants, who were born in the former Soviet Union or Ethiopia (1970–1993) and immigrated in childhood to Israel. Each participant's body mass index was measured at approximately 17 years of age. Odds ratios were calculated for obesity and overweight according to age on arrival to Israel. A total of 52,503 Israel-born participants with origins in those same countries were measured at the same age and used as references. A total of 52,258 native Israelis without known immigrating ancestry were also used for comparison. The risk stratification accounted for possible socio-demographic confounders and birth year.ResultsForeign-born immigrants had decreased risk for obesity and overweight relative to Israeli-born immigrants when measured at the age of 17 years. However, those who arrived in Israel during infancy and early childhood (before the age of 3 years) had greater risk for high weight compared with those immigrating during late childhood and adolescence.ConclusionsAlthough generally protective against obesity and overweight relative to native, these beneficial effects of immigration are diminished for those arriving in early childhood rather than later in adolescence.