(252) Trends in Childhood BMI, Overweight, and Obesity among 7-year-old Girls during the Last Six Decades

Background: Childhood obesity is associated with increased risk of adult obesity and future disease.

Objectives: The aim with the present study was to describe the trend for childhood BMI, overweight, and obesity among seven-year-old girls in Sweden born between 1946 and 2006.

Methods: We collected information on BMI at seven years of age from archived school health records in the population-based BMI Epidemiology Study cohort in Sweden for all girls born every five years between 1946 and 2006. We included thirteen birth cohorts with 750 girls each (total n=9750), and used birth cohort 1946 as reference. Descriptive statistics, t-test, chi2-test, and linear regression were used to assess the trend.

Results: In the reference cohort, the mean childhood BMI at seven years of age was 15.50 (SD=1.58) kg/m2 and for every decade until 2006, there was an increase in childhood BMI of 0.14 kg/m2 (95% CI: 0.13;0.16). Mean childhood BMI increased significantly (p < 0.05) from birth cohort 1971 compared to the reference cohort. We also observed an increasing trend in the frequency of both overweight and obesity until birth year 1996, compared with the reference cohort. A maximum prevalence of overweight (16.4 %) and obesity (7.7 %) was seen for 1996. After 1996, there was a decline in both mean BMI (p < 0.001) and the prevalence of overweight including obesity (p < 0.01) when comparing 1996 with both 2001 and 2006.

Conclusions: In the present study, we describe the trend in childhood BMI, overweight, and obesity among girls during the last six decades, capturing both the rise and the recent decline. Given the association between childhood BMI and adult future disease, monitoring of the obesity epidemic is important for prediction of future disease burden.