More than half of all adults and a third of children and adolescents will be overweight or obese by 2050 unless urgent action is taken, according to the most comprehensive global analysis to date, published by The Lancet to coincide with World Obesity Day on Tuesday.

This poses an “unparalleled threat of premature disease and death at local, national, and global levels”, according to the Global Burden of Disease Study BMI Collaborators.

Overweight and obesity rates in adults (25 or older) and children and adolescents (5-24 years) have more than doubled between 1990 and 2021, affecting 2.1 billion adults (up from 731 million) and 493 million young people (from 198 million).
“The unprecedented global epidemic of overweight and obesity is a profound tragedy and a monumental societal failure,” said lead author Professor Emmanuela Gakidou from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in the US.

In 2019, the estimated total costs associated with obesity, including both direct and indirect costs, ranged from $3·19 billion in low-income countries to $1·33 trillion in high-income countries. 

Forecasts suggest that, by 2035, the obesity epidemic could lead to a 2·9% reduction in global gross domestic product, equating to a loss of $4 trillion.

“Especially high levels have already been reached in Oceania and North Africa and the Middle East, with over 62% of adult males in Nauru, Cook Islands, and American Samoa, and over 71% of adult females in Tonga and Nauru living with obesity in 2021,” according to a media release from The Lancet.

China, India, the US, Brazil, Russia, Mexico, Indonesia and Egypt accounted for more than half of the global population living with overweight and obesity in 2021.

The US had the highest rates of obesity among high-income countries, with around 42% of males and 46% of females affected by obesity in 2021.

 In Latin America, 15 of the 17 countries had a prevalence of obesity among females of more than 30%.

However, the largest future increases are projected in Asia and sub-Saharan Africa, driven by growing populations. 

No country has curbed adult obesity

No country to date has successfully curbed the rising rates of adult overweight and obesity

Among males, the prevalence of overweight and obesity was above 87% in Nauru, American Samoa, Northern Mariana Islands, Cook Islands, and Kuwait. 

In future, the highest levels for men are predicted in the United Arab Emirates and Nauru, where more than 80% of males are expected to have obesity in 2050.

Among females, the prevalence has reached 88% and above in Tonga, Kuwait, Cook Islands, Nauru, and Samoa. In future, Tonga and Egypt are predicted to dominate with at least 87% of females being overweight or obese by 2050.

“Obesity rates are skyrocketing across sub-Saharan Africa, with 522 million adults and more than 200 million young people expected to be living with overweight or obesity by 2050,” said co-author Awoke Temesgen, Associate Professor at IHME. 

In Nigeria, the number of overweight and obese adults is projected to more than triple from 36.6 million in 2021 to 141 million in 2050.

“Action is urgently needed to implement preventative initiatives such as policies on the marketing of unhealthy foods and planning to include facilities for exercise and playing fields in schools,” added Temesgen.

Obesity trends in young people

The study predicts a 121% rise in obesity among young people globally by 2050, with the total number of children and adolescents with obesity predicted to reach 360 million. 

The most rapid increases in obesity in young are forecast for North Africa,  the Middle East, Latin America and the Caribbean, where one-third of all the world’s children and adolescents with obesity (130 million) are expected to live in 2050. 

The transition to obesity predominance (versus overweight) is also expected to be overwhelming for several Oceanic countries, including the Cook Islands, Nauru, Tonga where levels of obesity are expected to reach 60-70% by 2050, as well as for heavily populated countries such as Nigeria (18.1 million), India (26.4 million), Brazil (17.8 million),  China (35.2 million), and the US (22.1 million).

The authors also note that more recent generations are gaining weight faster than previous ones and obesity is occurring earlier, increasing the risk of complications such as type 2 diabetes, high blood pressure, cardiovascular diseases, and multiple cancers occurring at younger ages. 

“Our estimates identify children and adolescents in much of Europe and south Asia living with overweight who should be targeted with obesity prevention strategies,” said co-lead author Dr Jessica Kerr from Murdoch Children’s Research Institute in Australia. 

“We have also identified large populations, particularly adolescent girls, in North America, Australasia, Oceania, north Africa and the Middle East, and Latin America that are expected to tip over to obesity predominance and require urgent, multifaceted intervention and treatment.”

Action plans

The authors stress that five-year action plans (2025-2030) are urgently required to curb the rise in obesity and help inform new goals and targets post-2030, when the Sustainable Development Goals end.

“Preventing obesity must be at the forefront of policies in low- and middle-income countries,” said Kerr. 

“Policy action in these regions must balance the challenges of overnutrition with undernutrition and stunting, with interventions ranging from support for nutritional diets and regulating ultra-processed foods to promoting maternal and child health programmes that encourage pregnant women to follow a healthy diet and breastfeed. 

Kerr warned that many countries “only have a short window of opportunity to stop much greater numbers shifting from overweight to obesity”.

She called for “much stronger political commitment” to “transform diets within sustainable global food systems and to support comprehensive strategies that improve people’s nutrition, physical activity and living environments, whether it’s too much processed food or not enough parks.”

Image Credits: Jen Wen Luoh.