Measuring nutritional knowledge using Item Response Theory and its validity in European adolescents

Thanise Sabrina Souza Santos, Cristina Julian, Dalton Francisco De Andrade, Betzabeth Slater Villar, Raffaela Piccinelli, Marcela González-Gross, Fréderic Gottrand, Odysseas Androutsos, Mathilde Kersting, Nathalie Michels, Inge Huybrechts, Kurt Widhalm, D. Molnár, Ascensión Marcos, Manuel J. Castillo-Garzón, Luis A. Moreno

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1 Citation (Scopus)


ObjectiveTo analyse the Nutritional Knowledge Test (NKT) using Item Response Theory (ITR) analysis and to assess the construct validity of the Nutritional Knowledge Scale (NKTS) and its associations with adolescent food group consumption and nutritional biomarkers.DesignCross-sectional study.SettingMulticentre investigation conducted in ten European cities.ParticipantsAdolescents aged 12·5-17·5 years (n 3215) who completed over 75 % of the NKT.ResultsFactor analysis indicated that the NKT can be analysed with a one-dimensional model. Eleven out of twenty-three items from the NKT presented adequate parameters and were selected to be included in the NKTS. Nutrition knowledge was positively associated with consumption of fruits, cereals, dairy products, pulses, meat and eggs, and fish, as well as with blood concentrations of vitamin C, β-carotene, n-3 fatty acids, holo-transcobalamin, cobalamin and folate; nutrition knowledge was negatively associated with intake of olives and avocado, alcohol and savoury snacks.ConclusionsThe NKTS assessed nutritional knowledge adequately and it is proposed as a new tool to investigate this subject in future studies.

Original languageEnglish
JournalPublic Health Nutrition
Publication statusAccepted/In press - Jan 1 2018



  • Diet
  • Knowledge
  • Nutrition
  • Psychometrics
  • Scales

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Nutrition and Dietetics
  • Public Health, Environmental and Occupational Health

Cite this

Souza Santos, T. S., Julian, C., De Andrade, D. F., Villar, B. S., Piccinelli, R., González-Gross, M., Gottrand, F., Androutsos, O., Kersting, M., Michels, N., Huybrechts, I., Widhalm, K., Molnár, D., Marcos, A., Castillo-Garzón, M. J., & Moreno, L. A. (Accepted/In press). Measuring nutritional knowledge using Item Response Theory and its validity in European adolescents. Public Health Nutrition.