Weight Perception Varies by Local Peer Body Size Norms Among <scp>US</scp> Adolescents

INTRODUCTION: Biological normalcy is a framework that examines relationships between statistical norms (e.g., variation, distribution) of biological traits and normative understandings of biology at the population level. We use this biocultural framework to test whether weight perception varies by local peer body size norms (BSNorm) in a nationally representative sample of US adolescents. METHODS: We used 2023 Youth Risk Behavior Survey data. Weight perception was assessed as "underweight," "about right," or "overweight." Local peer BSNorm was derived by calculating the proportion of peers with BMI ≥ 85th percentile within each locality. Linear regression tested the relationship between weight perception and BSNorm, controlling for sex, age, race/ethnicity, and BMI category (lower-range: < 5th percentile, mid-range: 5th-< 85th percentile, upper-mid-range: 85th-< 95th percentile, upper-range: ≥ 95th percentile). Subgroup analyses by sex and BMI category were performed. RESULTS: BSNorm was negatively associated with weight perception in the full sample (β = -0.60, p = 0.0005) and both sexes separately (females: β = -0.70, p = 0.0004; males: β = -0.50, p = 0.01). The association was primarily driven by adolescents in mid-range (β = -0.58, p < 0.0001) and mid-upper-range (β = -0.76, p = 0.037) BMI categories. By sex-specific weight categories, weight perception was negatively associated with BSNorm among females in the lower-range BMI category (β = -2.37, p = 0.015) as well as males (β = -0.44, p = 0.014) and females (β = -0.76, p < 0.0001) in the mid-range BMI category. There were no associations among adolescents in the upper-range BMI category. CONCLUSION: Overall, weight perception decreased as local peer BSNorm increased. This association held for both males and females and appears to be largely driven by adolescents in the mid- and upper-mid BMI ranges.