Epidemiology of childhood obesity

Prevalence of childhood obesity has increased dramatically worldwide. A Lancet article published in 2010 that the prevalence of childhood obesity during the past two to three decades, much like the United States, has increased in most other industrialized nations, excluding Russia and Poland. Between the early 1970s and late 1990s, prevalence of childhood obesity doubled or tripled in Australia, Brazil, Canada, Chile, Finland, France, Germany, Greece, Japan, the UK, and the USA.

A 2010 article from the American Journal of Clinical Nutrition analyzed global prevalence from 144 countries in preschool children (less than 5 years old). Cross-sectional surveys from 144 countries were used and overweight and obesity were defined as preschool children with values >3SDs from the mean. They found an estimated 42 million obese children under the age of five in the world of which close to 35 million lived in developing countries.11 Additional findings included worldwide prevalence of childhood overweight and obesity increasing from 4.2% (95% CI: 3.2%, 5.2%) in 1990 to 6.7% (95% CI: 5.6%, 7.7%) in 2010 and expecting to rise to 9.1% (95% CI: 7.3%, 10.9%), an estimated 60 million overweight and obese children in 2020.

The National Survey of Children's Health (NSCH) has facilitated estimation of childhood obesity rates at state levels and comparison of geographic differences in social and behavioral factors. In the United States, 17% of children and teenagers in the United States are considered obese (BMI ≥95th percentile of the sex specific 2000 CDC growth charts). Prevalence has remained high over the past three decades across most age, sex, racial/ethnic, and socioeconomic groups, and represents a three-fold increase from one generation ago and is expected to continue rising.

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