The current study examined whether weight status and student perceptions of their weight were associated with academic grades in selected secondary school courses (math and English/French) in a large population study of Canadian youth. Results support the links between obesity, as determined by BMI, and lower academic performance in both males and females. Overweight BMI classifications were also associated with lower odds of high grades in English/French courses among females, and in math classes among male students, relative to BMIs considered “normal-weight”. Similar to previous research , females with overweight perceptions were less likely to achieve higher course grades in math, and both males and females with overweight perceptions had lower odds of grades above 60% in their English/French courses, relative to their peers with perceptions of being at “about the right weight”, controlling for BMI classification and covariates. While no effect was found for underweight relative to “normal-weight” BMI, females and males with perceptions of being underweight had lower odds of high grades in math and English/French courses relative to students with “about the right weight” perceptions. Results for youth with missing BMI or weight perception data resembled those for obesity BMI classifications and perceptions of overweight or underweight, respectively. Overall, this study demonstrates that an obesity achievement gap remains when controlling for students’ perceptions of their weight, and that weight perceptions—both underweight and overweight—predict lower academic performance, regardless of BMI classification. Further research is needed to determine the mechanisms underlying these relationships, in order to remove barriers to academic success among youth with larger body sizes, and those with perceptions of deviating from “about the right weight”.
To the best of our knowledge, only one previous study has examined weight perception as a predictor of academic grades. The current study provides necessary replication and builds on existing literature, by examining these relationships in a more recent and larger sample of youth. In a sample of approximately 11,000 US adolescents participating in the 2003 Youth Risk Behavior Study, perceptions of overweight were found to be a stronger predictor of academic outcomes than BMI, and obesity was no longer a significant predictor of academic performance when accounting for overweight perceptions . Overweight perceptions have been linked to poor mental health, psychosocial distress, and low self-esteem in adolescents [29,38-40], factors that have also been associated with lower academic achievement . In fact, researchers have reported perceiving oneself as overweight to be a stronger predictor of behavioural issues and mental distress than actual weight status [13,27,40]. Similarly, the current results indicate that perceptions of overweight significantly predicted poorer academic outcomes independent of BMI classification, with the exception of math grades in males. However, unlike Florin et al. , obesity BMI classifications remained predictive of lower grades when controlling for weight perception.
The current study suggests other factors appear to contribute to the obesity achievement gap, such as parental education, mental health, or external weight bias. Students with obesity are more likely to experience weight-based bullying within the school context [28,39]. Also, weight bias has been documented in physical education teachers [9,43,44,54] and given its pervasiveness across the population [9,43], may contribute to educators’ perceptions of students’ academic abilities. Several studies have indicated that the association between BMI and academic performance was no longer significant when models adjusted for parental/familial characteristics [12,47]. For instance, Datar et al. concluded that overweight status is not a causal factor of lower academic performance, as weight-related differences in test scores became insignificant when social and behavioural variables, such as SES and parental time spent with the child were considered . The authors cautioned that higher weight students may be labeled as lower achievers, as weight is a more obvious marker than sociodemographic characteristics.
Adolescents who perceive themselves as overweight may be at risk of internalizing weight stigma. Despite the high prevalence of obesity, weight stigma continues to be problematic. Stereotypes that individuals living with obesity are lazy, unintelligent, or lack willpower contribute to stigma and discrimination . Internalized stigma, or self-stigma, occurs when individuals apply negative stereotypes to themselves and believe that the stigma is deserved , leading to low self-esteem and psychological distress . Research indicates that bias toward individuals with overweight and obesity persists in health care, employment, and home settings . Education, however, has received less research attention, particularly at the secondary school level. It is plausible that adolescents who perceive themselves as overweight have lower self-concepts related to internalized weight stigma, which in turn, contributes to poorer academic engagement and performance. That is, students who feel their weight is “about right” may be more likely to succeed because they have not internalized negative stereotypes.
Students with underweight perceptions also reported lower grades than those with “about right” perceptions. Interestingly, the effect of underweight perceptions was more consistent than overweight perceptions in predicting lower grades in both females and males, and across Math and English/French grades. To our knowledge, no previous study has examined underweight perceptions in relation to academic performance. While less studied, underweight perceptions have been associated with depressive and anxiety symptoms in males [21,41,42] and suicidality and lower health-related quality of life in all youth [25,27]. Based on this result, it is plausible that links between weight perception and academic performance relate more to deviations from the social norm or sociocultural body ideals than to weight stigma. Results are consistent with sociocultural body ideals of thinness for women and muscularity for men, with more males reporting underweight perceptions than females. About one-fifth of males and one-tenth of females reported underweight perceptions; yet only 1.5% and 2.1% of female and males had BMIs classified as underweight, respectively. Another plausible explanation is that youth with underweight perceptions were experiencing weight restrictions (e.g., due to food insecurity) and/or had lost weight, while “normal-weight” by BMI, which in turn contributed to reduced ability to perform in school. Results highlight the importance of including weight perceptions across the spectrum in future research.
Interestingly, students that did not report their body weight or weight perception tended to have the lowest likelihood of achieving higher grades, comparable to the odds for obesity BMI classification. Far more males and females with missing BMI data reported perceptions of overweight than their peers with “normal-weight” BMIs. Adolescents are less likely to report their weight as BMI increases and if they have poor body image [35,45]. Missing self-reported weight status and perceptions may be influenced by an awareness of societal norms of thinness/muscularity ideals and weight bias attitudes [45,46]. Hence, if adolescents with larger body sizes did not report their weight due to concerns of judgment by others, results lend support to the theory that negative perceptions regarding body weights outside of “about right” contribute to lower academic performance.
Future research should explore both internalized and externalized weight bias, and associated lower self-concept and mental distress, as possible mechanisms explaining links between higher weight status, and perceptions of overweight and underweight, with academic achievement. Upstream strategies targeting the negative connotations of varying body sizes may prove valuable, to prevent the adverse psychosocial outcomes associated with perceptions of being overweight or underweight. Enhanced efforts to prevent weight-based bullying and promote weight acceptance are also advised. Previous research suggests bullying victimization predicts changes from perceptions of being at “about the right weight” to underweight and overweight perceptions among youth .