Background: There is an evidence of social inequalities in weight status in adolescence but the diversity of family socioeconomic status (SES) indicators can lead to discrepant findings. We aimed to identify how combination of family SES indicators can help measuring weight socioeconomic gradient (WSG) among adolescents.
Methods: Cross-sectional data from 2113 adolescents (13-18 years old) of the PRALIMAP-INÈS trial were used. Multiple SES indicators and assessment of weight status including body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and self-perception of overweight were used. We used principal component analysis (PCA) followed by structural equation models to identify SES dimensions. A dimension normalized score was calculated ranging from 1 to 10 (a high score corresponding to high SES). Linear regression models (linear trend test) were used to assess the WSG.
Results: Three SES dimensions were identified: (i) 'Family social status', (ii) 'Family education level' and (iii) 'Family income level'. BMI was significantly lower in highly advantaged compared with highly less advantaged [-1.64 (-2.39; -0.89) for family social dimension, -0.86 (-1.37; -0.36) for family education level and -2.35 (-3.65; -1.05) for family income level]. Similar results were observed for all weight indicators excepted for self-perception of overweight status. Socially less advantaged adolescents perceived themselves less fat than they were.
Conclusion: Although WSG was evident in adolescence, association between SES and weight status differed according to objective or perceived weight indicators. The proposed SES dimension can be applied in other field and future studies are needed to confirm our findings.