A new comprehensive analysis published in The Lancet warns that approximately 260 million Americans could be overweight or obese by 2050 if current trends continue, representing about 80% of the U.S. population. The study, conducted by researchers at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, projects that obesity rates will increase more rapidly than overweight rates in the coming decades.
The research estimates that by 2050, two in three adults, one in three teenagers, and one in five children in the United States will be classified as obese. This represents a significant acceleration of a trend that has been building for decades.
"Our analysis lays bare the decades-long failure to tackle the growing overweight and obesity epidemic in the USA," said lead study author Emmanuela Gakidou, a professor with IHME. "Overweight and obesity can trigger serious health conditions — many of which are now occurring at younger ages, including diabetes, heart attacks, stroke, cancer, mental health disorders and even premature death."
Alarming Trends Across Age Groups
The study combined 134 unique data sources, including major national surveillance survey data, to estimate future overweight and obesity rates. Researchers found that nearly three-quarters of the adult U.S. population was already overweight or obese in 2021.
Particularly concerning is the rapid increase in obesity rates, which doubled between 1990 and 2021 in both men (19% to 42%) and women (23% to 46%). By 2050, researchers project that about 213 million Americans aged 25 and older will be carrying excess weight, along with more than 45 million children and young adults between the ages of 5 and 24.
The analysis also revealed that people are becoming obese at earlier ages than previous generations. About two in five women born in the 1960s were obese by age 45, but the same proportion had become obese by age 30 for those born in the 1980s.
Teenage obesity rates more than doubled in the U.S. between 1990 and 2021, increasing from 9% to 23% in boys and 10% to 29% in girls. In 2021, an estimated 15 million children and teens and more than 21 million young adults were already overweight or obese.
Geographic Disparities
The study identified significant geographic disparities in obesity rates across the United States, with the highest levels concentrated in the South. This regional pattern is expected to continue into the future.
By 2050, two-thirds of men in West Virginia and Kentucky and two-thirds of women across 12 states are projected to be obese. States with particularly high projected obesity rates include Mississippi, West Virginia, Arkansas, and Illinois.
Among young adults, the highest obesity rates in 2050 are expected in Oklahoma (43% of men), Mississippi (39.8% of men), and West Virginia (37.7% of men). For young adult women, at least half of those living in Mississippi, Arkansas, Oklahoma, and Alabama are projected to be obese by 2050.
However, in absolute numbers, California (1.53 million) and Texas (1.49 million) will continue to have the largest populations of young obese adults in 2050 due to their larger overall populations.
Global Context
The U.S. obesity crisis is part of a broader global trend. A related study published in The Lancet in March 2025 found that more than half of adults and a third of children and teens worldwide will be overweight or obese by 2050.
Among high-income countries, America had the highest rates of obesity, with about 42% of men and 46% of women classified as obese in 2021. The U.S. is projected to have the third-largest number of adults with overweight and obesity by 2050 (214 million), behind only China (627 million) and India (450 million).
Public Health Implications
The projected surge in obesity rates has serious implications for public health and healthcare systems. The increasing prevalence of obesity is expected to drive higher rates of chronic diseases, including diabetes, heart disease, stroke, and certain cancers.
"The soaring health system and economic costs will be equally pervasive, with over 260 million people in the USA, including over half of all children and adolescents, expected to be living with overweight or obesity by 2050," Gakidou noted.
While newer weight-loss medications like Wegovy and Zepbound may help some individuals manage their weight, researchers emphasize that addressing the obesity epidemic will require broader policy interventions.
"Given the predicted surge in overweight and obesity, demand for anti-obesity medication will definitely increase, but it is not a silver bullet," said study co-author Marie Ng, an affiliate associate professor with IHME.
Prevention Strategies
Researchers stress that reversing the obesity epidemic will require comprehensive government action beyond simply telling people to eat less and exercise more.
"Above all, reversing the U.S. obesity epidemic will rely on the government supporting programs that increase levels of physical activity, such as investing in safe and walkable neighborhoods, guaranteeing the availability of healthy food to children and adolescents, regulating the food and marketing industries and achieving environmentally sustainable food systems," Gakidou said.
The researchers emphasize that while the projections are concerning, they are not inevitable. With appropriate interventions targeting both prevention and treatment, particularly for younger populations, the trajectory of the obesity epidemic could potentially be altered.
As Jessica Kerr from Murdoch Children's Research Institute noted in the global obesity study, "If we act now, preventing a complete transition to global obesity for children and adolescents is still possible."
