In a remarkable and concerning development in global nutrition, children around the world are now more likely to be classified as obese than underweight. As reported in UNICEF’s latest Child Nutrition Report, approximately 9.4 percent of school-aged children, aged 5 to 19, are living with obesity, while 9.2 percent are underweight. This marks a significant shift from 25 years ago when nearly 13 percent of children were underweight compared to just 3 percent with obesity. The trajectories of these two forms of malnutrition have converged and now flipped.
Traditionally, obesity and underweight have been viewed as distinct issues—one stemming from scarcity and the other from excess. However, public health experts now recognize both as forms of malnutrition. They categorize malnutrition into three dimensions: insufficient food intake, excessive consumption of unhealthy food, and hidden hunger due to micronutrient deficiencies.
While the decline in underweight children is a positive development, indicating fewer kids are dangerously thin—a condition that can lead to stunted growth, impaired brain development, and weakened immunity—the alarming rise in obesity cannot be overlooked. Currently, 188 million children are grappling with obesity, and the prevalence is not uniform worldwide; it varies significantly by region.
The implications of childhood obesity extend far beyond mere weight concerns. It elevates the risk for serious health issues such as Type 2 diabetes, high blood pressure, cardiovascular diseases, and even certain cancers in later life. As these children grow, the costs associated with obesity are projected to escalate dramatically. By 2035, the economic burden of overweight and obesity is expected to surpass $4 trillion annually, accounting for about 3 percent of the global GDP.
UNICEF’s projections, based on survey data through 2022, indicate that this crossover occurred around 2025. Although the exact timing may hold some uncertainty, the overarching trend is unmistakable, with child obesity rates expected to continue rising through 2030, particularly in Latin America, the Middle East, and East Asia.
This shift aligns closely with changes in the food environments that children inhabit today. Supermarkets, schools, and corner stores are increasingly stocked with high-calorie foods laden with added sugars, saturated fats, and salt. Items such as soft drinks, processed snacks, and instant noodles dominate the market, often designed to be cheap, convenient, and appealing to young consumers.
Marion Nestle, a respected authority on food politics at New York University, emphasizes that food companies operate as businesses motivated by profits, not as entities focused on public health. This has resulted in unhealthy foods becoming widely accessible, even in low- and middle-income countries, where they are beginning to displace traditional diets.
The term “ultra-processed foods” has gained traction in health discussions, referring to products that are typically high in calories and low in nutritional value. Research from the US National Institutes of Health has shown that individuals consuming ultra-processed diets consume approximately 500 more calories per day than those on minimally processed diets. Although many studies associate ultra-processed food consumption with obesity and other health issues, establishing direct causation remains challenging.
Debates continue about what constitutes “ultra-processed,” with some experts arguing that existing classification systems are overly broad and can combine vastly different food types. Critics like Nicola Guess argue that the category can be unhelpful, as it may group dissimilar items, such as Oreos and tofu, under the same label.
Nevertheless, the consensus among experts is clear: diets high in heavily marketed, calorie-dense products correlate with poorer health outcomes. Rafael Pérez-Escamilla, a public health nutrition professor at Yale University, notes that the association between these diets and adverse health effects is strong, approaching a causal relationship.
In addition to dietary changes, children’s physical activity levels have significantly decreased compared to previous generations. Global surveys indicate that more than 80 percent of adolescents fail to meet the World Health Organization’s recommendation of one hour of daily exercise. This sedentary lifestyle exacerbates the negative impacts of poor dietary choices.
The consequences of these shifts are evident across the globe, with disparities in child obesity rates. Wealthier nations like the United States (21 percent), Chile (27 percent), and the United Arab Emirates (21 percent) report alarming rates of childhood obesity. In certain Pacific Island regions, over a third of children are classified as obese, a trend linked to increased reliance on imported processed foods.
However, this trend is not universal. In regions such as sub-Saharan Africa and South Asia, underweight remains a more pressing issue than obesity. This disparity highlights a complex landscape of progress and crisis where some areas grapple with food scarcity while others contend with the consequences of poor dietary options.
The root causes of this dramatic shift in child malnutrition are structural, influenced by pricing, marketing, and food availability. Addressing these issues is crucial for developing effective solutions. Many Latin American countries are taking proactive measures, motivated by concerns about the economic strain obesity-related chronic diseases may impose on their healthcare systems.
Chile’s introduction of warning labels and advertising restrictions in 2016 significantly reduced purchases of sugary beverages and snacks. Similarly, Mexico’s recent ban on junk food in public schools aims to reshape dietary choices for millions of children. Impact studies indicate these measures have been effective. The United Kingdom’s soft drink tax has also encouraged companies to reformulate beverages to contain less sugar.
Conversely, efforts in the United States, such as the Make America Healthy Again movement, have fallen short of delivering substantial policy changes. Critics argue that the movement lacks concrete regulations and merely promotes research and voluntary guidelines, failing to enact meaningful change in public health.
While no single piece of legislation can reverse the obesity trend, implementing comprehensive measures such as warning labels, soda taxes, and marketing restrictions can significantly contribute to a healthier future for children.
The decline in underweight rates should be acknowledged and celebrated; however, the rise in obesity reframes our understanding of malnutrition in the 21st century. The focus must shift from merely counting calories to scrutinizing the quality of the calories consumed. In a world where we have made strides in addressing one crisis, we now face another exacerbated by our food systems.
