Roughly 890 million adults worldwide are living with obesity, based on the most recent global data from 2022. That works out to about 16% of all adults aged 18 and older. When you add in people who are overweight but below the obesity threshold, the number jumps to 2.5 billion, nearly a third of the world’s adult population.
Global Numbers at a Glance
The World Health Organization’s 2022 figures paint the clearest picture. Of the planet’s roughly 5.5 billion adults, 890 million have a body mass index (BMI) of 30 or higher, the standard cutoff for obesity. Another 1.6 billion are overweight, with BMIs between 25 and 29.9. Together, overweight and obesity affect more people than any single infectious disease on Earth.
These numbers are not evenly distributed. Pacific Island nations top the global rankings: American Samoa has the highest obesity rate at just over 70%, followed closely by Nauru (about 70%) and Tokelau (67%). These are small populations, but their rates illustrate how dramatically obesity prevalence can vary by region, diet, and lifestyle. Larger, wealthier nations like the United States, the United Kingdom, and several Middle Eastern countries also rank well above the global average.
Obesity in the United States
The U.S. has one of the highest obesity rates among large countries. As of the most recent national survey data (August 2021 through August 2023), 40.3% of American adults aged 20 and older meet the criteria for obesity. That’s roughly 2 in every 5 adults. Another 31.7% are overweight, meaning nearly 3 out of 4 American adults carry excess weight by BMI standards.
Within that 40.3%, about 9.7% of adults have severe obesity, defined as a BMI of 40 or higher. Severe obesity carries substantially greater health risks, including a higher likelihood of type 2 diabetes, sleep apnea, heart disease, and joint problems.
Rates Differ by Race and Ethnicity
Obesity does not affect all demographic groups equally in the United States. Non-Hispanic Black adults have 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 have the lowest rate at 17.4%. These gaps reflect a complex mix of factors: differences in food access, neighborhood walkability, income, chronic stress, and historical patterns of health care access all play a role. Genetics contribute, but environment and socioeconomic conditions are the primary drivers of these disparities.
Childhood Obesity
The numbers aren’t limited to adults. In the United States, about 1 in 5 children and adolescents aged 2 to 19 have obesity, totaling approximately 14.7 million young people. For children, obesity is measured differently than for adults. Rather than a fixed BMI cutoff, a child is considered obese if their BMI falls at or above the 95th percentile for others of the same age and sex.
Childhood obesity is particularly concerning because it tends to persist into adulthood. Children who are obese at age 10 or 12 face significantly higher odds of remaining obese as adults, along with earlier onset of conditions like high blood pressure and insulin resistance that used to be considered middle-age problems.
How BMI Classes Break Down
Not all obesity is the same from a medical standpoint. BMI is divided into three classes that roughly correspond to increasing health risk:
- Class I (BMI 30 to 34.9): The largest group. Many people in this range feel relatively healthy but face elevated long-term risks for heart disease, certain cancers, and metabolic problems.
- Class II (BMI 35 to 39.9): Sometimes called “serious obesity.” Health complications become more common and harder to manage at this level.
- Class III (BMI 40 and above): Often referred to as severe obesity. This group has the highest risk of life-threatening complications and is typically where surgical interventions are considered.
BMI is an imperfect tool. It doesn’t distinguish between muscle and fat, and it can misclassify very muscular or very short individuals. But at a population level, it remains the most practical way to track trends and compare rates across countries.
Where the Numbers Are Headed
The trajectory is steep. The World Obesity Federation projects that more than half the global population, 51%, will be living with overweight or obesity by 2035 if current trends continue. The economic toll is projected to match: global costs associated with overweight and obesity, including healthcare spending and lost productivity, are expected to reach $4.32 trillion per year by 2035.
The fastest growth is happening in low- and middle-income countries that are undergoing rapid urbanization. As processed food becomes cheaper and more available, and as physical labor gives way to sedentary work, populations that historically had low obesity rates are catching up quickly. This shift is already visible in parts of sub-Saharan Africa, Southeast Asia, and Latin America, where obesity rates have climbed sharply over the past two decades.