About 4 in 10 American adults have obesity, and roughly 1 in 10 have severe obesity. That translates to well over 100 million adults living with a body mass index (BMI) of 30 or higher. The numbers are even more striking when you include children: nearly 14.7 million young people aged 2 to 19 also meet the threshold.
The Latest Adult Numbers
The most recent national data, collected by the CDC between August 2021 and August 2023, puts the age-adjusted prevalence of severe obesity (BMI of 40 or higher) at 9.7% of adults aged 20 and older. That’s the most extreme category alone. When you add in Class I obesity (BMI 30 to 34.9) and Class II obesity (BMI 35 to 39.9), the total adult obesity rate sits around 40%, a figure that has climbed steadily for decades.
As of 2024, every single U.S. state and territory had an adult obesity prevalence of at least 25%. Mississippi and West Virginia were the highest, each crossing the 40% mark. Only eight states and the District of Columbia remained in the lowest bracket, between 25% and 30%.
Childhood Obesity Rates
Among children and adolescents aged 2 to 19, obesity affected 19.7% of the population from 2017 through early 2020. That works out to approximately 14.7 million young people. Childhood obesity is measured differently than adult obesity, using age- and sex-specific BMI percentiles rather than fixed cutoffs, but the trajectory mirrors what’s happening in adults: steady increases over the past several decades.
Who Is Most Affected
Obesity rates vary significantly across racial and ethnic groups. Data from the 2017 to 2018 reporting cycle found that non-Hispanic Black adults had the highest prevalence at 49.6%, followed by Hispanic adults at 44.8% and non-Hispanic white adults at 42.2%. Non-Hispanic Asian adults had the lowest rate at 17.4%.
The gap is especially pronounced among women. Non-Hispanic Black women had an obesity prevalence of 56.9%, compared with 43.7% for Hispanic women, 39.8% for non-Hispanic white women, and 17.2% for non-Hispanic Asian women. Among men, the differences between non-Hispanic white, Black, and Hispanic groups were narrower, clustering between roughly 41% and 46%.
Income and Education
The relationship between obesity and socioeconomic status is less straightforward than many people assume. Among women, the pattern is clear: obesity prevalence was 45.2% in the lowest income group compared with 29.7% in the highest. Among men, the picture flips somewhat. Men in the lowest and highest income brackets actually had similar obesity rates (31.5% and 32.6%), while middle-income men had the highest prevalence at 38.5%.
Education shows a more consistent trend. College graduates had an obesity prevalence of about 28%, while adults with some college or a high school diploma clustered around 40%. But even these patterns don’t hold across every demographic. Among non-Hispanic Black men, for instance, obesity prevalence was actually higher in the highest income group (42.7%) than in the lowest (33.8%). The CDC has noted that the connection between obesity and income or education “is complex and differs by sex, and race/non-Hispanic origin.”
How Fast the Numbers Have Grown
In the year 2000, no U.S. state had an adult obesity prevalence above 30%. By 2024, no state was below 25%. That shift happened in just one generation. The rise in severe obesity has been particularly steep. A BMI of 40 or above was once rare enough that researchers barely tracked it as a separate category. Now nearly 1 in 10 American adults qualifies.
Projections suggest the trend isn’t slowing. A widely cited modeling study from the CHOICES Project at Harvard estimated that by 2030, about half of U.S. adults will have obesity and roughly a quarter will have severe obesity. If those projections hold, severe obesity will soon be more common than obesity was in total just a few decades ago.
The Financial Weight
Obesity carries enormous economic costs. The estimated annual medical spending attributable to obesity was nearly $173 billion in 2019. On an individual level, people with obesity paid about $1,861 more per year in medical costs than people at a normal weight. Those costs come from higher rates of conditions closely linked to excess weight, including type 2 diabetes, heart disease, joint problems, and certain cancers.
What BMI Actually Measures
All of these statistics rely on BMI, a simple ratio of weight to height. The standard categories are: Class I obesity for a BMI of 30 to 34.9, Class II for 35 to 39.9, and Class III (severe obesity) for 40 and above. For a person who is 5 feet 9 inches tall, a BMI of 30 corresponds to about 203 pounds.
BMI is useful for tracking population-level trends, but it has real limitations for individuals. It doesn’t distinguish between muscle and fat, doesn’t account for where fat is stored on the body, and can misclassify people who are muscular or who carry weight in less metabolically harmful areas. Researchers and clinicians increasingly recognize that BMI alone doesn’t capture someone’s actual health risk, which is why newer obesity staging systems try to incorporate factors like blood sugar, blood pressure, and physical function alongside weight.