Predictors of erroneous perception of being overweight among adolescents

Comparison of Perceived and Measured Body Composition in a Military Population: An Exploratory Study

INTRODUCTION

Weight status perception (WSP) is the subjective assessment of one's own body weight. It is not correlated with the body mass index (BMI). People practicing sports, including overweight people, tend to perceive themselves as normal weight. The military is in a paradoxical position between the need to gain muscle mass for professional purposes while respecting BMI standards. Using body composition might be more advantageous than using BMI as part of an individual approach in making a decision about fitness to serve. However, measuring body composition is not easy in current practice, and a bridge between WSP and body composition would make it possible to develop a simple assessment tool.

MATERIALS AND METHODS

This was a prospective, descriptive, cross-sectional study. We collected sociodemographic data, anthropometric data, and WSP.

RESULTS

Thirty-eight subjects were included. Among them, 71.1% were male. Mean age was 31.2 years (SD 8.9). The BMI was greater than 25 for 15 (39.5%) subjects. Twenty-four (63.2%) defined themselves as being overweight. Thirteen were overweight according to fat percentage (Fat%). A significant association (P = .008) was found between WSP and Fat%.

CONCLUSION

We were able to show a statistically significant association between WSP and Fat%. Such an association may be of great interest because the measurement of the Fat%, whatever the method used, is not easy in current practice. A replication of the study in the general population would be of great interest, especially since Fat% is closely associated with the incidence of cardiovascular diseases and many cancers.

Predictors of One-Year Change in How Youth Perceive Their Weight

Overall, perceptions of being at "about the right weight" appear advantageous for youth physical and mental health, regardless of BMI classification, whereas perceptions at either extreme (overweight or underweight) may negatively impact health behaviours and mental health. Instead of considering weight misperceptions as problematic, some researchers have proposed that underestimations of weight status may offer resiliency among individuals with overweight or obesity. Promoting "about right" WPs and preventing change to overweight or underweight perceptions may offer an effective public health strategy for supporting youth health over time. However, limited prospective evidence exists on factors that shape perceptions of weight status over time. The current study examined modifiable predictors of one-year change in weight perception among youths. We used 2-year linked data of 18,112 grade 9-12 students from Year 3 (Y₃:2014-2015) and Year 4 (Y₄:2015-2016) of the COMPASS study. Generalized Estimating Equation models tested screen use, physical activity, and bullying victimization as predictors of change from perceptions of "about the right weight" to "overweight" or "underweight" perceptions, adjusting for Y₃ covariates (body mass index, ethnicity, and grade) and school cluster. Results support the value of team sports among females and resistance exercise among males as protective against changes to overweight or underweight perceptions over one year. Also, various forms of bullying victimization predicted overweight perceptions in males and females. Watching TV/movies or messaging/texting for over 2 hours/day was associated with overweight and underweight perceptions, respectively, in females only. Playing video/computer games for over 2 hours/day was associated with overweight perceptions in males and underweight perceptions in females. Findings support the potential of bullying prevention, limiting certain screen use, and supporting engagement in team sports for females and resistance exercise for males as strategies to maintain perceptions of being at "about the right weight."