Projecting Global Trends and Inequalities in Adult Overweight and Obesity, 2023-2040: Findings From the NCD-RisC Database.

Abstract

This study quantifies the global burden of overweight and obesity, projects future trends, and examines associated health inequalities. Overweight and obesity burden data were obtained from the NCD-RisC database. Trends from 1990 to 2022 were analyzed, and a Bayesian model was used to project changes for 2023-2040. Cross-national health inequalities were measured using the slope index of inequality (SII) and the relative concentration index (RCI). Globally, overweight prevalence rose from 17.50% in 1990 to 28.00% in 2022 (average annual percentage change [AAPC] = 1.48%) and is projected to reach 43.97% by 2040 (AAPC = 1.13%). Obesity prevalence grew from 6.44% to 16.06% (AAPC = 2.46%) and is projected to surge to 38.96% by 2040 (AAPC = 4.96%). The SII for overweight burden dropped from 33.74% in 1990 to 16.24% in 2022, and it is projected to reverse to -2.42% by 2040. For obesity (BMI, ≥ 30.0 kg/m²) and mild obesity (BMI, 30.0-34.9 kg/m²), the SII declined from 20.12% to 18.58% and from 14.22% to 10.02%, respectively, with further drops to 9.35% and -1.70% by 2040. From 1990 to 2040, the share of the global prevalence burden of overweight and obesity in countries with the lowest GDP per capita rose from 15% to 22% and from 6% to 26%, respectively. The relative gradient inequality, measured by RCI, also showed similar findings. The global burden of overweight and obesity has significantly increased from 1990 to 2040. Health inequalities decreased from 1990 to 2022, with the burden mainly in higher-income countries. However, by 2040, the burden of overweight and mild obesity is projected to shift to lower-income countries, highlighting the need for targeted health policies and interventions.