Over one billion people lived with obesity in 2022
Obesity is excess body fat that harms health; adults usually meet the label at BMI over 30 kg/m², with 25–30 called overweight. In 2022 more than one billion people were obese—879 million adults and 159 million children—more than double adult counts from 1990.
Causes braid diet, inactivity, automation, urban life, genes, medicines, mental illness, economic policy, endocrine disease, and endocrine-disrupting chemicals. Many lose weight temporarily; durable maintenance is uncommon. Prevention needs medical, social, community, family, and personal levers; clinicians still lead with diet quality and exercise, sometimes adding drugs or surgery. It ranks among leading preventable causes of death as rates climb in both adults and children; about 12.1 percent of the world’s adults were obese in 2022.
WHO adult thresholds set overweight at BMI 25+ and obesity at 30+. For ages five to nineteen, obesity is BMI two standard deviations above the age median; under five, weight three deviations above median for height. Surgical writing subdivides higher classes; BMI 35 or 40+ often marks severe obesity, with morbid and super categories at still higher cut-points when comorbidities appear. Japan has used BMI above 25 and China above 28 because metabolic harm arrives earlier in some Asian populations.
Scholars often prefer body-fat percentage—above roughly 32 percent in women and 25 percent in men per some bariatric guidance—treating BMI as a convenient proxy.
BMI misfires on muscular bodies. More than half of NFL players count as obese by BMI and one in four as extremely obese, yet their average body fat is about 14 percent, well inside a healthy range; in one study of college sumo wrestlers, 40 percent stopped counting as obese once body fat replaced BMI. Canada's Edmonton Obesity Staging System adds medical, functional and mental-health factors across five stages. The stakes are large: the WHO estimated in 2021 that obesity causes at least 2.8 million deaths a year, and severe obesity at a BMI of 40 or more cuts life expectancy by about ten years. Among non-smokers, mortality bottoms out at a BMI of 20 to 25. Oddly, some groups fare better at higher weight, an obesity survival paradox first described in 1999 among hemodialysis patients and since seen in heart failure.
Source: Obesity
