2.3. Questionnaires and Scales
ADVERSE EVENTS
The characteristics of the questionnaires used may be found in the protocol [Study-specific questionnaires were used: an initial study questionnaire assessing demographic, life-style and health-related data and the inclusion criteria for the study, and a monitoring questionnaire administered every 15 days to gain information on any adverse events or exclusion criteria emerging during the intervention period.Validated scales were used to study the diet (the Food Frequency Questionnaire by Wądołowska [The questionnaires were provided as both editable electronic (sent by e-mail) and paper-and-pencil forms. This allowed the suitability of the methods for data collection to be compared.