From grit to flourishing: physical literacy’s mediating role in enhancing well-being among college students with obesity

Participants

A total of 385 obese undergraduate students were recruited from six major universities in Guangzhou, China: Sun Yat-sen University, South China Normal University, Jinan University, South China University of Technology, Guangzhou University, and South China Agricultural University. Participants ranged in age from 18 to 22 years (M = 19.54, standard deviation (SD) = 0.84), with 60.52% identifying as male and 39.48% as female. Inclusion criteria required participants to be enrolled as full-time undergraduate students and classified as obese, defined by a body mass index (BMI) ≥ 30 kg/m² according to the World Health Organization (WHO) (World Health Organization, 2024). Table 1 presents the detailed characteristics of the participants.

Recruitment and sampling

Participants were recruited over a six-month period via university health centers, student associations, and campus-wide email announcements. We first obtained a list of students identified as having obesity during routine health check-ups or through self-report. Invitations were then randomly distributed via emails and posters, ensuring a balanced approach across the six universities. Although the final sample had a somewhat higher proportion of males (60.52%), this distribution aligns with the response rates observed in our target population within these universities. Students were eligible if they were (a) full-time undergraduates and (b) classified as having obesity (BMI ≥ 30 kg/m²). Written informed consent was obtained from all participants.

Measures

Procedure

The study was conducted in accordance with the ethical standards of the Declaration of Helsinki and was approved by the Institutional Review Board of Jinan University (Approval Number: JNUKY-2023-0154). According to the approved protocol, this cross-sectional survey study was part of a broader project investigating exercise training and physical literacy in college students. Ethical approval covered both the intervention and any secondary analyses arising from the data. Interested students completed a screening session where trained research assistants measured height and weight to confirm BMI. After eligibility was confirmed, participants were provided with a secure link to an online survey that included demographic items and the main instruments (Grit-S, PPLI-SC, and the PERMA-Profiler). The presentation of the main instruments was randomized to minimize order effects, and all surveys were completed anonymously online.

Although random invitations were distributed across all six universities, a notably higher proportion of male students (n = 233) than female students (n = 152) ultimately enrolled in the study. This imbalance appears to reflect underlying demographic patterns observed in the participating institutions: health screening records showed a slightly higher prevalence of obesity among male undergraduates, and a greater willingness among male students to volunteer for weight-related health research (Karnes et al., 2021). Because no stratification by sex was imposed during recruitment, these factors led to a naturally higher male-to-female ratio in our sample.

Sample size

The study size was determined based on a priori power analysis to detect a medium effect size (f² = 0.15) in the mediation model with three predictors, using G*Power 3.1 software. A minimum of 143 participants was required to achieve 80% power at a 0.05 significance level. To account for potential dropouts, incomplete data , and to allow for further subgroup analyses, the target sample size was increased. Ultimately, 385 participants were successfully recruited, providing even greater power and robustness for our mediation analyses.

Data analysis

All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS, version 26.0). Descriptive statistics (means, standard deviations) were calculated for grit, physical literacy, and well-being (PERMA) scores. Skewness and kurtosis values were examined to assess the normality of data distributions. Bivariate Pearson correlation analyses were conducted to explore the relationships among grit, well-being, and physical literacy dimensions (Motivation, Confidence and Physical Competence, and Interaction with the Environment). These correlations provided preliminary insights into the associations between the variables. To test the mediating effect of physical literacy on the relationship between grit and well-being, the SPSS PROCESS macro (version 3.5) was employed. Specifically, Model 4 of the PROCESS macro was utilized to assess the mediation effect. Bootstrapping procedures with 5,000 resamples were applied to generate bias-corrected 95% confidence intervals (CIs) for the indirect effects. An indirect effect was considered statistically significant if the 95% CI did not include zero. This non-parametric resampling method enhances the robustness of the mediation analysis, particularly in cases where normality assumptions may not hold. All statistical tests were two-tailed, with a significance level set at p < 0.05.

Preliminary analyses

All participants provided complete and valid responses for all measures, with no missing data detected. Descriptive statistics and correlations among grit, well-being, and physical literacy (including the subdimensions) are presented in Table 2. The skewness (—skewness— < 2) and kurtosis (—kurtosis— < 7) values indicated that the data were approximately normally distributed. To control for Type I error due to multiple comparisons, we adjusted the significance threshold using the Bonferroni correction, setting it at 0.05/6 = 0.008. Because the physical literacy score is the sum of its three subdimensions, we did not perform correlation analyses between each subdimension and physical literacy itself, in order to avoid redundancy and potential issues with multicollinearity.

Mediation analysis using total physical literacy score

The PROCESS macro (Model 4) was employed to test the mediation effect of physical literacy between grit and well-being among college students with obesity. Grit was designated as the focal predictor (X); physical literacy was the proposed mediator (M). X and M were incorporated as predictors in an ordinary least-squares regression analysis to predict the students’ well-being (Y). Building upon the following regression equations, the results of the bootstrapping analysis are presented in Table 3. (1)${\displaystyle Y=a_1+cX+{\varepsilon }_1}$ (2)${\displaystyle M=a_2+aX+{\varepsilon }_2}$ (3)${\displaystyle Y=a_3+c^{{}^{\prime }}X+bM+{\varepsilon }_3}$ where a, b, and c’ estimate the paths separately.

The mediation analysis demonstrated that grit was significantly positively associated with physical literacy (β = 0.12, F = 28.81, p < 0.001). Physical literacy was also significantly positively associated with well-being (β = 0.56, F = 925.94, p < 0.001). The total effect of grit on well-being was significant (total effect = 0.76, 95% CI [0.63–0.89]), and when physical literacy was included in the model, the direct effect of grit on well-being remained significant but was reduced (direct effect = 0.56, 95% CI [0.45–0.67]), accounting for 73.68% of the total effect. The indirect effect of grit on well-being through physical literacy was significant (indirect effect = 0.20, 95% CI [0.09–0.31]), accounting for 26.32% of the total effect; since the bootstrap confidence interval did not include zero, this confirms that physical literacy partially mediates the relationship between grit and well-being among college students with obesity.

Parallel mediation analysis using physical literacy subdimensions

To further investigate the mediating effects of the subdimensions of physical literacy on grit and well-being, we employed a parallel mediation model. This analytical approach tested the mediating effects of the three subdimensions of physical literacy—motivation (M₁), confidence and physical competence (M₂), and interaction with the environment (M₃)—on the relationship between grit (X) and well-being (Y). (4)${\displaystyle M_1=a_{1}X+{\varepsilon }_1}$ (5)${\displaystyle M_2=a_{2}X+{\varepsilon }_2}$ (6)${\displaystyle M_3=a_{3}X+{\varepsilon }_3}$ (7)${\displaystyle Y=c^{{}^{\prime }}X+b_1{M}_1+b_2{M}_2+3M_3+{\varepsilon }_4,}$

where a₁, a₂, a₃ are the coefficients representing the effect of grit on each mediator. b₁, b₂, b₃ are the coefficients representing the effect of each mediator on well-being. c′ is the direct effect of grit on well-being after accounting for the mediators.

The results of the parallel mediation analysis are presented in Tables 4 and 5. Figure 1 presents the graphical representation of the mediation model and the regression coefficients. As shown in Table 4, grit was significantly positively associated with all three subdimensions of physical literacy: motivation (β = 0.07, F = 10.86, p < 0.001), confidence and physical competence (β = 0.08, F = 12.20, p < 0.001), and interaction with the environment (β = 0.21, F = 93.17, p < 0.001). Each subdimension was also significantly positively associated with well-being. Table 5 shows the mediating effects; the total effect of grit on well-being was significant (effect value = 0.76, standard error (SE) = 0.07, lower limit of the confidence interval (LLCI) = 0.63, upper limit of the confidence interval (ULCI) = 0.89), and when considering the mediators, the direct effect of grit on well-being remained significant but was reduced (effect value = 0.51, LLCI = 0.40, ULCI = 0.63), accounting for 67.11% of the total effect. The indirect effects through the subdimensions of physical literacy were all significant: motivation (indirect effect = 0.05, 95% CI [0.01–0.09]), accounting for 6.58% of the total effect; confidence and physical competence (indirect effect = 0.04, 95% CI [0.01–0.08]), accounting for 5.26% of the total effect; and interaction with the environment (indirect effect = 0.15, 95% CI [0.10–0.21]), accounting for 19.74% of the total effect.

Limitations and future directions

Despite the valuable insights, several limitations should be acknowledged. The cross-sectional design limits the ability to infer causality; longitudinal studies are needed to establish temporal relationships and examine how changes in grit and physical literacy over time impact well-being. Additionally, the reliance on self-report measures may introduce social desirability and recall biases; future research could incorporate objective measures of physical activity and physical competence, such as accelerometers or fitness tests, to validate self-reported data. The sample was limited to college students with obesity from universities in Guangzhou, China, which may affect the generalizability of the findings; cultural factors may influence perceptions of grit, physical literacy, and well-being, so replicating the study in different cultural contexts and including diverse populations would enhance the external validity of the results. Furthermore, while the study focused on physical literacy as a mediator, other potential mediators or moderators—such as social support, self-esteem, or mental health literacy—were not examined; exploring these factors could provide a more comprehensive understanding of the mechanisms linking grit and well-being.

Practical implications

These findings offer an important starting point for colleges and universities seeking to enhance psychological and physical well-being among students with obesity. Interventions that simultaneously address grit and physical literacy can be woven into existing campus frameworks, such as health centers and counseling services that incorporate resilience training, mindfulness, or goal-setting workshops designed to build perseverance; physical education departments that develop inclusive, skill-building courses and group-based sports aimed at reinforcing self-perceived competence and environmental engagement; and student affairs or campus recreation offices that organize peer-led fitness groups and social sport clubs to facilitate consistent participation and mitigate weight-related stigma. Community partnerships further extend resource availability for those who prefer off-campus settings, potentially reducing barriers to exercise and offering diverse opportunities to maintain motivation. By creating supportive social and physical environments, educators and administrators empower students with obesity to harness their grit more effectively, enabling them to persist through challenges while cultivating a stronger sense of accomplishment, connection, and overall well-being (Jefferies et al., 2019).