Overview of used questionnaires in the data collection process with the purpose
| Questionnaire | Who? | Purpose |
| Socodemographic (designed for the study) | All | Obtain family composition, education level and employment status of the parents, medical history and school level of the child. |
| Dutch Eating Behaviour30 | All | Measurement of restrained, emotional and external eating. |
| Food Frequency31–33 | All | Evaluation of food intake based on the frequency and portion size of 47 food items. |
| Developmental milestones (designed for the study—short 8-item) | All | Obtain child’s age at achieving the most obvious developmental milestones. |
| Strengths and Difficulties Questionnaire34–36 | All | Screening tool for mental health problems and common forms of psychopathology. |
| Developmental Coordination Disorder Questionnaire37 | ≥5 years | Detect Developmental Coordination Disorder (DCD) in children aged 5–15 years. |
| Ages and Stages Questionnaire38 | ≤5 years | Screening tool for neurodevelopmental disorders. |
| Paediatric Quality of Life Inventory)39 | ≥6 years | Measure the health-related quality of life according to the core dimensions of health. |
| Children’s Behaviour Questionnaire (very short form)40 | ≤6 years | Investigate temperament in preschool children. |
| Child Behaviour Checklist | ≥6 years | Additional differentiating (eventual) psychopathology. |