Decreasing prevalence of obesity among young children in Massachusetts from 2004 to 2008.

Objective: To examine whether the obesity prevalence is increasing, level, or decreasing among young US children (aged <6 years) in the past decade; and to compare regional data to those of 2 national databases.

Methods: We analyzed data from 108 762 well-child visits (36 827 children) at a multisite pediatric practice in eastern Massachusetts during 1999-2008. By using the Centers for Disease Control and Prevention 2000 gender-specific growth charts, we defined obesity as weight-for-length ≥95th percentile for children aged <24 months and BMI ≥95th percentile for children aged 24 to <72 months. By using multivariable logistic regression, we estimated gender-specific obesity trends in 2 separate periods, 1999-2003 and 2004-2008, adjusting for age group, race/ethnicity, health insurance, and practice site.

Results: From 1999 to 2003, the obesity prevalence was fairly stable among both boys and girls. From 2004 to 2008, the obesity prevalence substantially decreased among both boys and girls. The decline in obesity prevalence during 2004-2008 was more pronounced among children insured by non-Medicaid health plans than among those insured by Medicaid.

Conclusions: Among children aged <6 years at this multisite pediatric practice, obesity prevalence decreased during 2004-2008, which is in line with national data showing no increase in prevalence during this time period. The smaller decrease among Medicaid-insured children may portend widening of socioeconomic disparities in childhood obesity.