Underestimation of Overweight and Health Beneficial Outcomes in Two Adolescent Cohorts in Norway - The HUNT Study

Perceived body size across sex and weight categories and its association with body size dissatisfaction: a cross-sectional study among early primary school children in Norway

BACKGROUND

Inaccurate perceptions of body size, known as body size misperception (BSM), may be linked to body size dissatisfaction (BSD) and unhealthy eating behaviours. However, these associations remain inconclusive and not fully understood in young children. This study aimed to investigate the prevalence of BSM across sex and weight categories and to further assess the association between BSM and BSD in 8-to 9-year-old children.

METHODS

This cross-sectional study of 209 primary school children (51% boys) from central Norway was performed during the national height and weight screening program in third grade. Researcher-assisted questionnaires and Stunkard's figure rating scales adapted for children were used to assess two dimensions of body image: BSM (perceived-actual body size) and BSD (perceived-ideal body size). The agreement between children's ideal and actual body size was also evaluated (actual-ideal body size). Associations between BSM and BSD were examined by multinomial logistic regression, adjusting for sex, Body Mass Index (BMI), socioeconomic status, ethnicity, and residence.

RESULTS

BSM was frequently observed (81%), with most children overestimating their body size (67%). Boys tended to overestimate their body size more frequently (75% vs. 59%, p = 0.014) and indicated a larger mean ideal body size than girls (silhouette fig. 4.2 [95% CI 4.0, 4.5] vs. 3.9 [95% CI 3.7, 4.1], p = 0.012). According to BMI, overestimation was common among children with underweight (100%) and average weight (78%), whereas underestimation of body size was prevalent among children with overweight/obesity (59%). Although 23% desired at least one body size figure smaller or larger than their perceived size, interpreted as BSD, no difference was observed between mean perceived and mean ideal body size (silhouette fig. 4.1 in both groups). No significant association was found between BSM and BSD, for either underestimation (OR 1.32 [95% CI 0.33, 5.32]) or overestimation (OR 0.99 [95% CI 0.38, 2.58]) of body size.

CONCLUSIONS

Boys and girls from all weight categories frequently misperceived their body size toward their ideal body size, with overestimation of underweight and average weight status and underestimation of overweight status being most frequently reported. No association was found between BSM and BSD, however, the long-term health consequences of BSM should be further elucidated.

Body Image and Lifestyle Behaviors in High School Adolescents

This secondary data analysis study aimed to examine the associations between 1) body size perception (BSP) and body size dissatisfaction (BSD) and 2) lifestyle behaviors and BSP and BSD in adolescents. The study pooled cross-sectional data from two studies (n = 301) performed in adolescents. Weight and height were measured, while lifestyle behaviors and perceived actual and desired body size variables were self-reported. Linear regression analysis assessed the contribution of sex and zBMI to BSP and BSD scores. Pearson's correlation explored associations between BSP and BSD. Cohen's effect sizes compared satisfied and dissatisfied adolescents within the underestimators subgroup. A positive association between BSP and BSD scores was observed among girls living with normal-weight and overweight/obesity only (r = 0.26; p ≤ 0.001 and r = 0.38; p < 0.05, respectively). Underestimators who were satisfied with their body size showed a moderate effect size for a lower zBMI, a small effect size for lower screen time, and higher sleep duration compared to dissatisfied underestimators. Underestimation was associated with more body size satisfaction in adolescent girls with normal weight and overweight/obesity, suggesting a protective effect of underestimation. These findings support the hypothesis that body size satisfaction and underestimation in adolescents is associated with healthier lifestyle behaviors.