Affiliations: [a] Dip. per le Dipendenze, ASL Genovese, Genoa, Italy | [b] Dip. per le Dipendenze Patologiche, ASL AL, Alessandria, Italy | [c] Azienda U.L.SS. no. 6 “Vicenza”, Servizio di Igiene Alimenti e Nutrizione, Via IV Novembre 46, 35100 Vicenza, Italy. e-mail: [email protected]
Abstract: Background and aim: Studies to measure motivation for behavioural change were developed in Italy 15 years ago, following the validation of MAC and MAC2, Italian self-administered questionnaires created for heroin users, tobacco smokers and those with alcohol problems. This article presents the validation study of two sets of instruments created to assess motivation for change toward healthy nutrition and regular physical activity in Italian adult subjects who require or are referred for assessment or treatment to nutrition services. Methods and results: The two sets of questionnaires (created within the Nutrition Counselling Project connected to the Piano Triennale Sicurezza Alimentare 2005–2007 (Food and Nutrition Security Plan 2005–2007) of the Region of Veneto) were administered to 431 patients to assess motivation for change toward healthy nutrition and 450 patients to assess motivation for change toward regular physical activity. The instruments showed good internal consistency. Exploratory and Confirmatory Factor Analysis confirms the consistency with the theoretical assumptions. Reliability and concurrent validity yielded strong correlations with the corresponding variables. Conclusions: The study confirms the validity of the sets of instruments and their consistency with the model. These sets of instruments are the first psychometric tools integrating three factors (Discrepancy, Self-Efficacy, Readiness to Change) into a three-dimensional model of motivation for change.