Prevalence of obesity and extreme obesity in children aged 3-5 years

Abstract

Background: Early childhood adiposity may have significant later health effects. This study examines the prevalence and recognition of obesity and severe obesity among preschool-aged children.

Methods: The electronic medical record was used to examine body mass index (BMI), height, sex and race/ethnicity in 42,559 children aged 3-5 years between 2007 and 2010. Normal or underweight (BMI < 85th percentile); overweight (BMI 85th-94th percentile); obesity (BMI ≥ 95th percentile); and severe obesity (BMI ≥ 1.2 × 95th percentile) were classified using the 2000 Centers for Disease Control and Prevention growth charts. Provider recognition of elevated BMI was examined for obese children aged 5 years.

Results: Among 42,559 children, 12.4% of boys and 10.0% of girls had BMI ≥ 95th percentile. The prevalence was highest among Hispanics (18.2% boys, 15.2% girls), followed by blacks (12.4% boys, 12.7% girls). A positive trend existed between increasing BMI category and median height percentile, with obesity rates highest in the highest height quintile. The prevalence of severe obesity was 1.6% overall and somewhat higher for boys compared with girls (1.9 vs. 1.4%, P < 0.01). By race/ethnicity, the highest prevalence of severe obesity was seen in Hispanic boys (3.3%). Among those aged 5 years, 77.9% of obese children had provider diagnosis of obesity or elevated BMI, increasing to 89.0% for the subset with severe obesity.

Conclusions: Obesity and severe obesity are evident as early as age 3-5 years, with race/ethnic trends similar to older children. This study underscores the need for continued recognition and contextualization of early childhood obesity in order to develop effective strategies for early weight management.

Keywords: Children; obesity; preschool; severe obesity.

Figure 1. The proportion of children by sex and race/ethnicity according to BMI classification

BMI ≥ 95^th percentile – obesity, BMI ≥ 1.2 × 95^th percentile – severe obesity.

Figure 2. Median height percentile by body mass index (BMI) percentile in boys and girls

Significant differences in median height percentile were seen across BMI categories for each age-sex stratum, with a significant linear trend (p<0.001 within each age-sex category).

Figure 3. Proportion of children with BMI ≥ 95^th percentile (BMI 95^th-96^th percentile or BMI ≥ 97^th percentile) by increasing height quintile in boys and girls age three to five years old

P <0.001 for trend across increasing height category.