Childhood obesity is surging across the U.S., with severe health risks and deep racial disparities. A public health emergency that demands urgent national action.
A public health emergency
Childhood obesity has quadrupled between 1990 and 2022, according to data from the World Health Organization (WHO). In 2022, 37 million children under the age of 5 and more than 390 million aged 5 to 19 were overweight worldwide, including 160 million classified as obese.
The WHO warns that by 2030, 70% of the global population will be affected by overweight and obesity. Today, 43% of adults are overweight and 19% are obese.
These are alarming figures, with severe consequences for public health.
Childhood obesity in the United States
The study Prevalence of Extremely Severe Obesity and Metabolic Dysfunction Among US Children and Adolescents, published by the University of California San Diego in JAMA Network Open, highlights the alarming levels of childhood obesity in the U.S. The research involved 25,847 participants.
However, the problem has become global. In Europe, for example, about 1 in 3 children is overweight or obese.
Among children, obesity is defined as having a body mass index (BMI) above the 95th percentile for children of the same age and sex. Conventionally, childhood obesity is classified into three categories: class 1 (≥95th percentile), class 2 (120–140% of the 95th percentile), and class 3 (severe obesity, ≥140%).
The California study introduced two additional classes: class 4 (160–180% of the 95th percentile) and class 5 (≥180%). These new definitions aim to better identify the escalating health risks associated with extreme obesity.
Higher obesity, higher health risks
The findings show a clear correlation between obesity levels and health risks in children. The incidence of type 2 diabetes, prediabetes, hypertension, high cholesterol, and heart and liver disease increases with obesity severity. Some conditions, such as liver disease, can develop into cirrhosis or liver cancer in adulthood. Stroke risk is also elevated.
Insulin resistance, which often precedes these conditions, was present in 100% of participants in classes 4 and 5, compared to 81% in classes 1–3 and only 27% among non-obese children.
Overall, all health issues were more prevalent in higher obesity classes. Even lower obesity classes were associated with significantly higher health risks than those with a normal BMI.
The financial burden of obesity
The consequences of childhood obesity extend beyond health, placing an enormous burden on healthcare systems.
In the U.S., the costs of treating obesity-related conditions weigh heavily on families and public resources.
According to the authors, severe childhood obesity must now be considered a public health emergency. This calls for urgent public health interventions, starting with prevention and nutrition education.
A study on health and nutrition
The study analyzed data from 25,847 children and adolescents aged 2 to 18 who participated in the National Health and Nutrition Examination Survey (NHANES) between 2008 and 2023.
NHANES is a nationally representative U.S. survey that monitors health and diet through interviews, physical exams, and lab tests.
The aim was to examine national trends in childhood and adolescent obesity by gender, age, ethnicity, and race, and to assess the risk of metabolic dysfunction across obesity categories.
The results show a 253% increase in extremely severe childhood obesity. All other obesity categories also rose, though at lower rates. The increase was especially significant among adolescents aged 16 to 18 and non-Hispanic Black males.
Racial and ethnic disparities in obesity
The survey was conducted anonymously. Ethnic and racial identity, self-reported during NHANES interviews, was included in the California study to investigate health disparities and account for sociodemographic variables.
Gender distribution was balanced (49.0% female, 51.0% male), with a median age of 10 years (range: 6.0–15.0). Regarding race and ethnicity: 20.3% were Mexican American, 23.9% non-Hispanic Black, 30.0% non-Hispanic white, 11.1% other Hispanic, and 14.6% of other or multiracial origins.
Notably, boys showed higher rates of metabolic disease than girls, and younger children had lower prevalence of metabolic syndrome than teenagers.
While previous research had already shown higher obesity rates among non-Hispanic Black children, this study found especially high prevalence of class 4 and 5 obesity in this group. These results reinforce the urgency of tailored public health strategies to reduce racial and ethnic disparities in obesity.
Multiple causes behind childhood obesity
Childhood obesity is caused by a combination of factors: genetics, physical inactivity, and poor eating habits. There is a strong link between nutrition and socioeconomic status. Highly processed foods, which are attractive and tasty but often unhealthy due to high levels of additives, salt, and sugar, are widely accessible.
Processed foods are cheaper than healthy options, forcing low-income families to rely on products that are harmful to long-term health.
The role of eating habits
Eating habits make a difference. According to parental reports, 10.9% of children skip breakfast or eat inadequately (36.5%), often favoring large mid-morning snacks (66.9%) that tend to be unhealthy.
About 25.9% of children do not eat fruits and vegetables daily, though the daily intake of sugary and carbonated beverages has dropped (24.6%).
Roughly 37.0% of children eat legumes less than once a week, while 52.9% and 12.1% consume sweet and salty snacks more than three times a week, respectively.
Physical activity is still lacking
Physical activity indicators have remained largely unchanged in recent years, showing that more needs to be done to promote healthy lifestyles.
In 2023, 18.5% of children did not engage in any physical activity the previous day. Meanwhile, 41.5% still have a TV in their bedroom, and 45.1% spend more than two hours daily in front of screens.
Mothers’ perceptions also appear to be skewed:
- 45.0% of overweight or obese children are perceived as having normal or below-normal weight
- 59.6% of mothers of inactive children believe their child is active enough
- 73.0% of mothers of overweight or obese children believe their child’s food intake is not excessive
Schools are trying
On a positive note, schools are making efforts to support healthy habits:
- 76% of surveyed schools offer cafeteria services
- 48% distribute healthy foods
- 84% include nutrition education in their curriculum
- 27% involve parents in healthy eating initiatives
- 94% organize physical activity programs
- 23% involve parents in these programs
However, parental engagement in these initiatives remains limited.
