International study suggests there are more than one billion obese people worldwide

An international study involving Cristina Padez, Daniela Rodrigues and Aristides Machado-Rodrigues, researchers from the Research Centre for Anthropology and Health (CIAS) of the Faculty of Sciences and Technology of the University of Coimbra (FCTUC), suggests that more than one billion people worldwide are currently obese.

According to the research, published in The Lancet, these trends, coupled with a decline in the prevalence of underweight people since 1990, establish obesity as the most prevalent form of malnutrition in many countries.

"An analysis of global data estimates that the obesity rate among children and adolescents worldwide in 2022 was four times higher than in 1990. In Portugal, the prevalence of obesity among children and adolescents in 2022 was 6% for girls and 9% for boys. Among adults, the obesity rate had more than doubled for women and almost tripled for men. In total, 159 million children and adolescents and 879 million adults were considered obese in 2022," say the study's co-authors, who further add that in Portugal, “the prevalence of obesity that year was 23% in women and 22% in men."

Between 1990 and 2022, the proportion of children and adolescents worldwide who were underweight decreased by about one fifth for girls and by more than a third for boys. In Portugal, the prevalence of underweight/low weight in 2022 was 1% for girls and 3% for boys. Globally, the proportion of adults affected by underweight/low weight decreased by more than half over the same period. In Portugal, the figures were 2 per cent for both women and men in the same year.

According to the CIAS researchers, "Obesity and underweight are forms of malnutrition and are detrimental to people's health in many ways. This latest study provides a very detailed picture of global trends in both forms of malnutrition in the last 33 years".

"It is indeed worrying that the obesity epidemic that began in 1990 among adults worldwide is now being mirrored in school-aged children and adolescents. At the same time, a significant number of people, particularly in some of the poorest regions of the world, continue to be undernourished. To effectively address both forms of malnutrition, there is an urgent need to significantly increase the availability and affordability of healthy, nutritious food," cautions Professor Majid Ezzati of Imperial College London, lead author of the study.

The research, which involved more than 1,500 researchers, used body mass index (BMI) analysis to examine how obesity and underweight patterns have evolved globally from 1990 to 2022. The extensive research examined the weight and height measurements of more than 220 million people aged five and over, representing more than 190 countries, with 63 million aged between five and 19 and 158 million aged 20 and over".

Adults were classified as obese if their BMI was greater than or equal to 30 kg/m2 and as underweight if their BMI was less than 18.5 kg/m2. For schoolchildren (aged five to nine years) and adolescents (aged 10 to 19 years), the BMI criteria used to define obesity and underweight vary by age and sex, reflecting the significant changes in height and weight during childhood and adolescence," the study concludes.

This new study was conducted by the NCD Risk Factor Collaboration (NCD-RisC) in collaboration with the World Health Organization (WHO). The FCTUC researchers teamed up with Anabela Mota-Pinto, Luísa Mavieira and Lélita Santos from the Faculty of Medicine of the University of Coimbra (FMUC) and the Coimbra Hospital Centre (CHUC).

The scientific article is available here.