Consumer intentions to consume food supplements
: a survey study on its predictors, associated biased beliefs and risk-benefit perception

  • Rafael Ismail Vicêncio Miah (Student)

Student thesis: Master's Thesis


Research on consumers' habits concerning Food Supplements (FS) suggests an increase in its consumption in recent years. Despite several studies being conducted, specifically with the elderly and sports practitioners, there is insufficient research on the potential predictors of intentions to consume FS in a general, non-specific sample of the population. To fill such gap, a survey study grounded on an extended conceptual model adapted from the theory of planned behaviour was implemented, to assess predictors of FS consumption intentions such as: Consumer attitudes, intentions, self-efficacy, controlled perceived behaviour, injunctive norm, descriptive norm, general knowledge and beliefs, risk-benefit perception, trust in information sources and sociodemographic variables, were taken into consideration, alongside sociodemographic variables. 112 participants, showed to have a predominantly incorrect knowledge and beliefs regarding food supplements. Moreover, attitudes towards FS, risk-benefit perception, selfefficacy and the injunctive norm all were significant predictors of FS consumption intentions. Participants also showed high trust towards food safety National Authorities and European Union Institutions. Overall, the results exemplify the need for more studies on the general public, to have a wider understanding of FS consumption intentions, to implement risk prevention actions.
Date of Award28 Feb 2024
Original languageEnglish
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorRui Filipe Gaspar de Carvalho (Supervisor)


  • Food supplements
  • Intentions
  • Consumption
  • Risk-benefit perception
  • Knowledge
  • Trust
  • Biased beliefs


  • Mestrado em Psicologia na Gestão e Economia

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