For the first time in recorded history, more children worldwide are living with obesity than with underweight—a milestone UNICEF confirmed in September 2025, marking a fundamental shift in how global child malnutrition looks. Understanding what drove this crossover reveals as much about changing food systems as it does about changing bodies.
The Numbers Behind the Shift
The scale of this change is striking when laid out over time. Obesity surpassed underweight as the more prevalent form of malnutrition among school-aged children and adolescents globally, now affecting 1 in 10, or 188 million, school-aged children and adolescents worldwide. Looking at the trend since 2000, the prevalence of underweight among children aged 5 to 19 has declined from nearly 13 percent to 9.2 percent, while obesity rates have climbed from just 3 percent to 9.4 percent over the same period—a genuine reversal of two decades-old public health trends moving in opposite directions simultaneously. Research projections suggest this trend will accelerate further: by 2040, an estimated 228 million children aged 5 to 19 are expected to be living with obesity compared to 142 million living with underweight.
Changing Food Environments Are the Core Driver
The primary explanation researchers point to isn’t a mystery—it’s what children are eating and how that food reaches them. UNICEF’s report specifically links this shift to failing food environments, noting that ultra-processed food is increasingly dominating what children consume worldwide. These foods are typically engineered to be inexpensive, shelf-stable, heavily marketed, and calorie-dense, making them far more accessible and appealing to families than fresh, whole foods in many parts of the world—a genuine change in the food landscape compared to a generation ago.
The Shift Isn’t Happening Evenly Everywhere
This global transition looks very different depending on where you are. Obesity now exceeds underweight in nearly every region of the world, with the notable exceptions of sub-Saharan Africa and South Asia, where undernutrition still remains the more pressing concern. This regional divide reflects deep differences in food access, economic development, and the pace at which processed food industries have expanded into different markets, meaning the “global” obesity crossover masks very different local realities depending on a country’s food system and economic circumstances.
Where the Numbers Are Highest
Some of the starkest examples come from smaller nations with limited access to fresh food alternatives. Several Pacific Island countries have the highest prevalence of obesity globally, including 38 percent of 5 to 19-year-olds in Niue, 37 percent in the Cook Islands, and 33 percent in Nauru. But this isn’t just a small-island phenomenon—many wealthy, high-income countries also carry substantial rates, with 27 percent of children in Chile living with obesity, alongside 21 percent in both the United States and the United Arab Emirates.
Why This Still Counts as Malnutrition
It’s worth understanding why researchers frame childhood obesity as a malnutrition problem rather than simply a separate health issue. Malnutrition includes both too little and too much of the wrong kinds of nutrition, and obesity carries genuinely serious health risks for children and adolescents, placing them at elevated risk for chronic disease later in life. UNICEF’s leadership has emphasized this framing directly, with UNICEF Executive Director Catherine Russell noting that discussions of malnutrition can no longer focus solely on underweight children, since obesity itself represents a growing threat to children’s health and development.
The Broader Health Consequences
This shift matters beyond the raw statistics because of what it signals for future disease burden. Research tracking global trends has documented that both underweight and obesity carry adverse health outcomes throughout a person’s life, and researchers are increasingly tracking early signs of heart disease, stroke, diabetes, and liver disease showing up in children as a direct result of excess weight—conditions that were historically associated almost exclusively with adult populations until relatively recently.
Join The Discussion
Has this shift toward childhood obesity been something you’ve noticed in your own community, whether through school health programs, changing grocery store offerings, or your own family’s experience with food access? What do you think it would take to meaningfully shift food environments back toward healthier options for children? Share your thoughts, observations, or questions about this growing global health challenge below.
