Background/Objectives: Globally, childhood obesity remains a major public health priority, with increasing prevalence rates and widening inequity gaps. In Spain, evidence on obesity-related inequities across youth groups is relatively scarce, conducted at the local level, or outdated. Our objective was to examine absolute and relative social inequities in excess body weight (obesity and overweight) and abdominal obesity among Spanish youth in 2022, by age group, sex/gender, and socioeconomic status (SES).

Methods: We analyzed cross-sectional data from the PASOS study (2022), a nationally representative survey among children and adolescents, aged 8-16, in Spain. We assessed excess body weight and abdominal obesity using standardized anthropometric measurements (height, weight and waist circumference). We proxied SES through median household income, at the census section level, categorized into quartiles. We estimated prevalence ratios (PR) and 95% confidence intervals (95%CI) using multilevel Poisson regression models. We assessed both absolute and relative inequities by calculating both the slope index of inequality (SII) and the relative index of inequality (RII), adjusted by sex, age and region. We stratified all analyses by age group (8-11 vs. 12-16 years), and sex/gender.

Results: Youth from the lowest-SES quartile, compared with those from highest-SES, had higher prevalence of both excess body weight (adjustedPR = 1.39, 95%CI: 1.15-1.67) and abdominal obesity (adjustedPR = 1.83, 95%CI: 1.38-2.43). Overall, we observed more pronounced inequities for abdominal obesity ([SII = 11.1, 95%CI: 6.96, 15.3] [RII = 1.79, 95%CI: 1.43, 2.24]) than for excess body weight. Both absolute and relative inequities were highest among children than among adolescents. In younger children, inequities were stronger among girls for abdominal obesity, but more pronounced among boys for excess weight.

Conclusions/Recommendations: Social inequities in obesity among youth remain a significant challenge in Spain, particularly for younger children and for abdominal obesity. Our findings highlight the need for targeted and evidence-based policies and interventions tackling social inequities at early ages.