Determinants of supplementation among Canadian university students: a theory of planned behavior perspective

Abstract

Objective

The purpose of this study was to identify the psychosocial determinants of (1) intention to use dietary supplements (DS) and (2) the behavior of engaging in supplementation by testing the fit of the Theory of Planned Behavior (TPB).

Methods

A total of 778 students at a Canadian university in Ontario completed a cross-sectional survey assessing participants’ attitude, injunctive norm, descriptive norm, perceived behavioral control and intention toward DS use. Data were analyzed using independent sample t-tests and linear and logistic regressions.

Results

Attitude, injunctive norm and perceived behavioral control were significant predictors of intention to use DS. Attitude, injunctive norm and intention were significant predictors of engaging in supplementation. The model explained 75.5% of the variance and correctly classified 89.6% of cases. The odds of using DS doubled with every one-unit increase in intention.

Conclusions

This study confirms the utility of the TPB in predicting university students’ supplementation habits.

Keywords:

• Cognitive predictors
• dietary supplements
• supplementation
• theory of planned behavior
• university students

Conflict of interest disclosure

The authors have no conflicts of interest to report. The authors confirm that the research presented in this article met the ethical guidelines, including adherence to the legal requirements, of Canada and received approval from the Research Ethics Board of the University of Guelph.

Additional information

Funding

This work was funded by College of Social and Applied Human Sciences at the University of Guelph.