Norwegian children and adolescents in blended families are at risk of larger one‐year BMI increments

Abstract

Aim To study how sociodemographic factors and family structure associate with baseline BMI z‐scores (BMIz) and BMIz change in 767 Norwegian children aged 6‐15 years. Methods Baseline BMIz and 1‐year BMIz increments in children from the Bergen Growth Study were analysed with linear and logistic regression, according to sociodemographic factors and family structure. A blended family was defined as including a step‐parent and/or half‐sibling. Results In a fully adjusted regression model, baseline BMIz were only significantly associated with maternal BMI (b = 0.087, 95%CI 0.067, 0.107). Body Mass Index z‐scores increments were larger in children living in a blended family (b = 0.060, 95%CI 0.006, 0.115), with a lower parental education (b = 0.127, 95%CI 0.029, 0.226) and with a higher maternal BMI (b = 0.008, 95%CI 0.001, 0.014). The odds for a large BMIz increment (>1 SD) were higher in children living in blended families (OR 1.82, 95%CI 1.16, 2.88) and with higher maternal BMI (OR 1.07, 95%CI 1.01, 1.13) and lower in 9‐11‐year‐old children (OR 0.44, 95%CI 0.26, 0.77) compared with 12‐15‐year‐olds. Conclusion Body Mass Index z‐scores increments were more strongly associated with sociodemographic factors and living in a blended family than baseline BMIz values. BMI z‐scores increments could be useful for identifying children at risk of becoming overweight or obese.

Family structure in relation to body mass index and metabolic score in European children and adolescents

“…Overall, the findings of this study are in line with previous cross‐sectional and longitudinal research that observed a higher risk of overweight and a higher BMI in children from single‐parent families 6,9–11 and other non‐traditional families 6,12 . Along with earlier IDEFICS studies 5,6 and a recent systematic review, 34 we showed that living with siblings was associated with a lower BMI z ‐score.…”

“…Overall, the findings of this study are in line with previous cross‐sectional and longitudinal research that observed a higher risk of overweight and a higher BMI in children from single‐parent families 6 , 9 , 10 , 11 and other non‐traditional families. 6 , 12 Along with earlier IDEFICS studies 5 , 6 and a recent systematic review, 34 we showed that living with siblings was associated with a lower BMI z ‐score. Our study extends the current state of research by indicating that family structure is associated with the MetS which is, however, explained by the association with the BMI.…”

“…Previous research, including our own in the IDEFICS/I.Family cohort 5 , 6 , 7 , 8 has examined some aspects of family structure. It has been shown that children living in single‐parent families 6 , 9 , 10 , 11 or other non‐traditional family structures 6 , 12 are at higher risk of having overweight (including obesity) compared to those in two‐parent (biological) families. This may be due to a higher prevalence of obesogenic behaviours in children from these families when compared to two‐parent biological families.…”