Trends in the Prevalence of Clinical and Preclinical Obesity Among US Adults by Social Determinants of Health

OBJECTIVE: This study examined trends in clinical and preclinical obesity prevalence among US adults and their association with social determinants of health (SDOH) from 1999 to 2023. METHODS: We analyzed data from 60,506 adults aged ≥ 20 years in 11 cycles of the National Health and Nutrition Examination Survey (1999-2023). Clinical obesity was defined per the Lancet Diabetes & Endocrinology Commission on the definition and diagnosis of clinical obesity and preclinical obesity by excess adiposity without obesity-attributable complications. Eight SDOH domains were assessed individually and as a cumulative burden score. Age-standardized prevalence and associations were estimated using survey-weighted regression models. RESULTS: From 1999-2000 to 2021-2023, age-standardized prevalence of clinical obesity nearly doubled (14.3% to 26.6%; p < 0.001), driven by increases in class III obesity. Preclinical obesity increased modestly (17.1% to 20.6%; p = 0.038). Disparities widened significantly between those with highest (> 6) vs. lowest (< 3) cumulative SDOH burdens. In multivariable-adjusted analyses, unemployment (OR 1.50), food insecurity (OR 1.38), and high cumulative SDOH burden (OR 1.48) were strongly associated with clinical versus preclinical obesity, particularly class II-III severity. CONCLUSIONS: Clinical obesity increased dramatically, showing a strong dose-response relationship with social disadvantage and widening SDOH-based disparities, underscoring the need for targeted interventions addressing structural determinants among vulnerable populations.