Over 50% of the world’s population will be overweight or obese by 2035 unless significant action is taken, according to a new report released today.

The World Obesity Federation’s 2023 atlas predicts that 51% of the world, or more than 4 billion people, will be overweight or obese within the next 12 years.

Obesity rates are rising particularly rapidly among children and in lower-income countries, according to the report.

Calling the figures a “clear warning”, Louise Baur, president of the World Obesity Federation, said policymakers needed to act now to prevent the situation from worsening.

“It is particularly worrying to see obesity rates rising faster among children and adolescents,” she said in a statement.

“Governments and policy makers around the world need to do everything they can to avoid passing on health, social and economic costs to the younger generation,” he noted.

According to the report, childhood obesity could more than double from 2020 levels, reaching 208 million boys and 175 million girls by 2035.

The cost to society is significant because of the health conditions associated with being overweight, the federation said: more than $4 trillion annually by 2035, or 3% of global GDP.

However, the authors of the report note that they do not place the blame on the individual, but call for attention to be focused on social, environmental and biological factors involved in these conditions.

For these evaluations the authors of the report used the body mass index (BMI), a number calculated by dividing the weight by the square of the height. According to the guidelines of the World Health Organization (WHO), a person is overweight when his body mass index exceeds 25 and obese when it exceeds 30.

In 2020, 2.6 billion people fell into these categories, or 38% of the world’s population.

The report also concludes that almost all of the countries expected to see the largest increases in obesity in the coming years are low- or middle-income countries in Asia and Africa.

These figures will be presented to UN policymakers and member states next week.