Obesity & Overweight
Worldwide adult obesity has more than doubled since 1990 — 16% of adults are now obese and 39% are overweight. Childhood obesity rose four-fold over the same window. The medical class of GLP-1 receptor agonists is reshaping treatment in wealthy countries while access remains negligible in the global south.
Key insights
The Americas and Pacific lead
US adult obesity reached 42% in 2024 — the highest in the OECD. Pacific Island nations (Nauru, Tonga, Samoa, Palau) exceed 50% for both sexes. The lowest rates remain in South and East Asia (India 4%, Vietnam 2%, Japan 4.5%) though all are rising. Mexico (36%) and Chile (34%) have caught up with Western Europe.
Child obesity is the fastest-rising indicator
Children and adolescents living with obesity rose from 31 million (1990) to 160 million (2024). Childhood obesity tracks into adulthood in roughly 80% of cases and substantially raises lifetime risk of diabetes, cardiovascular disease and several cancers. The WHO has set a target of no increase in childhood obesity by 2025 — that target has been missed in every region.
GLP-1 drugs change the trajectory in rich countries
Semaglutide, tirzepatide and successor molecules produce 15–20% weight loss in trials. US uptake reached an estimated 12% of obese adults by end-2025. Cost ($10,000+/year) and supply constraints have limited use to wealthy markets. Early models suggest these drugs could lower US obesity prevalence by 3–5 percentage points by 2030 if access expands.
Adult obesity prevalence — selected countries (2026)
% of adults with BMI ≥ 30
Key Finding: Pacific Island nations dwarf the rest of the world; the US leads OECD; South/East Asia remain comparatively low but rising.
Adult obesity trend — major economies 1990–2026
% of adults with BMI ≥ 30
Key Finding: US adult obesity tripled from 14% (1990) to 42% (2024). Every country shown is on a rising trajectory; the slope varies but no large country has reversed it.
Methodology & caveats
BMI thresholds and limitations
BMI = weight (kg) / height (m)². WHO classifies overweight as BMI ≥ 25 and obesity as BMI ≥ 30. The thresholds do not adjust for muscle mass, frame size or ethnicity — Asian populations face cardiometabolic risk at lower BMI, prompting some health authorities to use BMI ≥ 27.5 as the obesity cut-off for these groups.
Self-report vs measured
Self-reported height and weight systematically understate obesity — people round up height and down weight. Population estimates that rely on health-examination surveys (the US NHANES, UK Health Survey) are 3–5 percentage points higher than self-reported equivalents. Cross-country comparisons should use the same survey type.
Double burden
Many low and middle-income countries now face a 'double burden' — adult and childhood obesity rising even as stunting and micronutrient deficiency persist among the poorest. This is not paradoxical: cheap, energy-dense calories from sugar, refined grains and oils have become widely available while diets remain deficient in protein and micronutrients.