More than 1 billion people worldwide are now estimated to have obesity

It’s no secret that global obesity rates have been rising over the past few decades. But a new analysis quantifies the upsurge.

More than 1 billion people worldwide were living with obesity as of 2022, researchers report February 29 in the Lancet. That’s about one-eighth of the global population (SN: 11/15/22). For comparison, nearly 800 million people had obesity in 2016, according to the World Health Organization, or WHO.

Obesity is “defined by the presence of excess body fat that impairs health,” says obesity expert Arya Sharma of the University of Alberta in Edmonton, Canada, who was not involved in the study. The chronic disease can raise the risk for conditions like heart disease and type 2 diabetes, vulnerability to diseases like COVID-19, and can also limit mobility and negatively affect mental health (SN: 4/22/20).

Global health researcher Majid Ezzati and colleagues examined more than 3,600 population-based studies published over the last several decades encompassing 222 million participants across nearly 200 countries and territories. The researchers divided each participant’s reported weight by their height squared to find their body mass index, or BMI.

Analyzing the trends suggested that in 2022, almost 900 million adults worldwide had a BMI of 30 or above, classifying them as having obesity. In children and adolescents ages 5 to 19, nearly 160 million were estimated to have the chronic disease, defined as BMI above a certain point on the WHO’s growth reference curves, which account for age and sex.

From 1990 to 2022, the prevalence of obesity roughly doubled in women, tripled in men and quadrupled in children and adolescents. At the same time, global rates of those who were underweight fell. “We shouldn’t be thinking about [underweight and obesity] as two separate things, because the transition from one to the other has been very rapid,” says Ezzati, of Imperial College London.

The estimated obesity rates should raise alarms, he says. “Governments and societies need to deal with this” through prevention and medical care. Despite new anti-obesity medications like Wegovy showing incredible results, Ezzati adds, their high costs and lack of incorporation in worldwide medical guidance will make them inaccessible to most people for the near future (SN: 12/13/23).

Ezzati notes that one of the biggest driving factors of obesity’s increased prevalence is limited access to and the unaffordability of healthy foods. Sharma adds that societal-level lifestyle changes — such as getting less sleep, increased stress levels and spending less time at home — can also lead to eating more processed foods and overconsumption (SN: 12/21/18; SN: 5/16/19).

“When you look at appetite, there’s a complex biology behind it,” Sharma says. “And that biology is affected by environmental changes.”