Overweight among New Zealand adolescents: associations with ethnicity and deprivation

OBJECTIVES: The objectives of the current study are: to describe the prevalence of overweight/obesity among New Zealand adolescents and to describe the demographic characteristics, including neighbourhood deprivation, associated with overweight/obesity. METHODS: Data for the current study were collected as part of Youth'07, a national survey of the health and well-being of 9 107 New Zealand secondary school students (approximate ages 13 to 17 years). Students answered a comprehensive, multimedia survey about their health and wellbeing and were weighed and measured for height. Small area deprivation was measured by the New Zealand Deprivation Index, based on the student's residential address. RESULTS: One in ten adolescents was obese and an additional 24% were overweight. Body size was significantly associated with small area deprivation (p<0.001) and ethnicity (p<0.001). Furthermore, the association between socioeconomic deprivation and body mass index (BMI) was moderated by ethnicity (p=0.035 for interaction term.) A positive association between BMI and socioeconomic deprivation was observed for Pacific students, Māori students and European students, but not for Asian students and students of other ethnicities. CONCLUSIONS: Our findings demonstrate a high prevalence of overweight/obesity among New Zealand adolescents, particularly for Pacific Island adolescents, Māori adolescents, and those living in areas of high deprivation.