More than one billion people are obese, finds study led by the Jameel Institute's Majid Ezzati

• One in eight people in the world – a total of more than 1 billion people – now lives with obesity.
• The new study, led by the Jameel Institute's Professor Majid Ezzati, analysed more than 3,000 population studies with 222 million people between 1990-2022.
• The study found that, taken together with the declining prevalence of people who are underweight, obesity is the most common form of malnutrition in most countries.
• The report estimates that, since 1990, obesity rates are up by around two times among women, three times among men and four times among children and adolescents.

New analysis led by Professor Majid Ezzati, a research lead in the Jameel Institute at Imperial College London, shows obesity rates have increased dramatically over the last three decades.

One in eight people in the world is now living with obesity, according to the work published in The Lancet that highlights changes to global trends in malnutrition over more than 30 years. The analysis finds that the total number of children, adolescents and adults worldwide living with obesity has surpassed one billion.

The report highlights that these trends, together with the declining prevalence of people who are underweight since 1990, make obesity the most common form of malnutrition in most countries.

Researchers estimate that among the world’s children and adolescents, the rate of obesity in 2022 was four times the rate in 1990. While among adults, the obesity rate more than doubled in women and nearly tripled in men.

According to the researchers, the latest findings highlight an urgent need for comprehensive policies to tackle the burden of malnutrition, including improving the accessibility and affordability of nutritious food, as well as prevention and management strategies for obesity and underweight.

Professor Majid Ezzati, research lead in the Jameel Institute and senior author of the study, said: “It is very concerning that the epidemic of obesity that was evident among adults in much of the world in 1990 is now mirrored in school-aged children and adolescents. At the same time, hundreds of millions are still affected by undernutrition, particularly in some of the poorest parts of the world. To successfully tackle both forms of malnutrition it is vital we significantly improve the availability and affordability of healthy, nutritious foods.”

In the latest study, conducted by the NCD Risk Factor Collaboration in collaboration with the World Health Organisation (WHO), researchers set out to analyse trends in obesity and underweight – both forms of malnutrition which are detrimental to health in many ways.

Researchers analysed weight and height measurements from over 220 million people aged five years or older (63 million people aged five to 19 years, and 158 million aged 20 years or older), representing more than 190 countries.

More than 1,500 researchers contributed to the study, which looked at body mass index to understand how obesity and underweight have changed worldwide from 1990 to 2022.

Dr Tedros Adhanom Ghebreyesus, director-general of the WHO, said: “This new study highlights the importance of preventing and managing obesity from early life to adulthood, through diet, physical activity, and adequate care, as needed. Getting back on track to meet the global targets for curbing obesity will take the work of governments and communities, supported by evidence-based policies from WHO and national public health agencies. Importantly, it requires the cooperation of the private sector, which must be accountable for the health impacts of their products.”

In all age groups, the combined burden of both forms of malnutrition increased in most countries between 1990 and 2022, driven by increasing obesity rates. However, the double burden of malnutrition declined in many countries in South and Southeast Asia, and in some countries in Africa for men, where the rate of underweight fell steeply.

Dr Guha Pradeepa, study co-author from the Madras Diabetes Research Foundation, said: “The impact of issues such as climate change, disruptions caused by the COVID-19 pandemic, and the war in Ukraine risk worsening both rates of obesity and underweight, by increasing poverty and the cost of nutrient-rich foods. The knock-on effects of this are insufficient food in some countries and households and shifts to less healthy foods in others. To create a healthier world, we need comprehensive policies to address these challenges.”

The rise in double burden has been greatest in some low-income and middle-income countries, particularly those in Polynesia and Micronesia, the Caribbean and the Middle East and North Africa. These countries now have higher obesity rates than many high-income industrialised countries, especially those in Europe.

The Jameel Institute, in Imperial's School of Public Health, was founded by Imperial College London and Community Jameel in October 2019 to combat disease threats worldwide. Led by Professor Neil Ferguson, director, and Professor Katharina Hauck, deputy director, the Jameel Institute tackles both outbreaks of infectious disease and non-communicable diseases, like obesity. The team led by Professor Ezzati that published the current study also includes Dr Bin Zhou, a research fellow at the Jameel Institute.

For more information, find The Lancet paper here and the Imperial College London article (from which this announcement is adapted) here.