Epidemiology of Childhood Obesity and Associated Health Risks

Childhood obesity has emerged as a paramount public-health challenge worldwide, with prevalence rising sharply over recent decades and stabilising at high levels in many regions. Obesity in early life not only increases the risk of persistence into adulthood but also predisposes young people to a spectrum of comorbidities including type 2 diabetes, hypertension, dyslipidaemia, non-alcoholic fatty liver disease and psychosocial difficulties. The distribution of obesity is highly stratified by socioeconomic status, ethnicity and geographic region, reflecting complex interactions between genetic susceptibility, early-life exposures, dietary patterns, physical activity and built-environment factors. Secular trends indicate that while some high-income communities have witnessed modest declines or plateaux in overall obesity rates, the prevalence of severe obesity continues to rise or remains stubbornly high, particularly among marginalised groups. Classifying obesity by degree of severity—using percentiles relative to age- and sex-specific growth charts—has highlighted dose–response relationships between excess adiposity and the clustering of cardiometabolic risk factors. Early identification of at-risk children, coupled with targeted prevention and intervention strategies, is essential to avert the long-term burden of chronic disease and to reduce health inequities on a global scale.

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Epidemiology of Childhood Obesity and Associated Health Risks publication trend

The graph below shows the total number of articles in epidemiology of childhood obesity and associated health risks across all publications each year (not limited to Nature Index journals).

Technical terms

Body mass index (BMI): A measure of weight relative to height (kg/m2) used to classify underweight, overweight and obesity in children, adjusted for age and sex.

BMI percentile: A child’s position relative to a reference population; the 95th percentile is commonly used as the threshold for obesity.

Severe obesity: Defined as BMI ≥120% of the 95th percentile or higher, indicating very high levels of adiposity and elevated cardiometabolic risk.

Cardiometabolic risk factors: A cluster of conditions—hypertension, dyslipidaemia, insulin resistance and elevated liver enzymes—that increase the risk of cardiovascular disease and diabetes.

Metabolic syndrome: The co-occurrence of multiple cardiometabolic risk factors above defined thresholds, signifying heightened risk for cardiovascular events.

References

1. Cardiometabolic risk factors among children and adolescents with overweight and Class 1 obesity: A cross-sectional study. Insights from stratification of Class 1 obesity. Frontiers in Endocrinology (2023).
2. Severe Obesity and Cardiometabolic Risk in Children: Comparison from Two International Classification Systems. PLOS ONE (2013).
3. Associations Between Family Income and Children’s Physical Fitness and Obesity in California, 2010–2012. Preventing Chronic Disease (2015).
4. Birth Weight, Childhood Body Mass Index and Risk of Coronary Heart Disease in Adults: Combined Historical Cohort Studies. PLOS ONE (2010).
5. Severe Obesity Among Children in New York City Public Elementary and Middle Schools, School Years 2006–07 Through 2010–11. Preventing Chronic Disease (2014).
6. Prevalence, Disparities, and Trends in Obesity and Severe Obesity Among Students in the School District of Philadelphia, Pennsylvania, 2006–2013. Preventing Chronic Disease (2015).
7. Trends in the Prevalence of Morbid and Severe Obesity in Australian Children Aged 7-15 Years, 1985-2012. PLOS ONE (2016).