Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults.
Level 3 - non-randomized controlled study
Pooled analysis and Bayesian hierarchical modeling of population-representative cross-sectional surveys across 200 countries.
PubMed 38432237 · doi:10.1016/S0140-6736(23)02750-2
What was done
Researchers pooled data from 3,663 population-based studies encompassing 222 million individuals with measured height and weight across 200 countries and territories. A Bayesian hierarchical model was used to estimate trends from 1990 to 2022 in the prevalence of underweight (BMI <18.5 kg/m²) and obesity (BMI ≥30 kg/m²) in adults aged ≥20 years, as well as thinness (BMI <2 SD below the WHO reference median) and obesity (BMI >2 SD above the WHO median) in school-aged children and adolescents aged 5–19 years.
What was found
From 1990 to 2022, the combined prevalence of underweight and obesity in adults increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability (PP) ≥0.80, while decreasing in only 11 countries (6%) for women and 17 (9%) for men. By 2022, adult obesity was more prevalent than underweight in 177 countries (89%) for women and 145 countries (73%) for men (PP ≥0.80), whereas underweight was more prevalent in 16 countries (8%) for women and 39 (20%) for men. Among school-aged children and adolescents, the combined prevalence of thinness and obesity increased in 140 countries (70%) for girls and 137 countries (69%) for boys (PP ≥0.80), while decreasing in 5 countries (3%) for girls and 15 (8%) for boys. By 2022, childhood obesity was more prevalent than thinness in 133 countries (67%) for girls and 125 countries (63%) for boys (PP ≥0.80), whereas thinness remained more prevalent in 35 countries (18%) for girls and 42 countries (21%) for boys. Across all groups, increases in the double burden were driven predominantly by rises in obesity, though thinness remained prevalent in South Asia and parts of Africa.
Why it matters
This study provides comprehensive global surveillance demonstrating that obesity has surpassed underweight as the primary form of malnutrition in most countries worldwide. It highlights an urgent need for policies that address rising obesity rates while maintaining efforts against persistent undernutrition in high-burden regions.
Limits
The findings depend on statistical hierarchical modeling to infer trends in countries and time periods with sparse empirical data. BMI was the sole anthropometric measure used, serving only as an indirect proxy for adiposity without capturing body composition or ethnic variations in fat distribution. Children under 5 years of age were not included in the analysis.
Cited by
- supports Globally, 1 billion people are obese and half a billion people are starving.