Table 6 Recommendations by parents to make the task more feasible for their child

Eye-tracking

- Make the stimuli more interesting (14x), for example by:

 • Using more attention-grabbing videos and sounds

 • Personalizing the stimuli to the participant

 • Making the task more interactive using a touch-screen

- Skip or improve calibration (7x; e.g., by making the calibration target more interesting)

- Improve the surroundings of the measurement (2x; as they found the Sophia Bus to be small and distracting)

fNIRS

- Make a practice cap that also includes the protruding tips of the optodes (2x; as this feeling was the most challenging for the participant)

- Make the task stimuli more appealing to the participant (2x)

- Do the measurement at home instead of in the Sophia Bus (1x)

- Use a time timer (1x)

- Allow the participant to stand instead of sit during the measurement (1x)

Indirect calorimetry

- Have a big TV screen on the ceiling with a distracting video (4x; instead of a video on a smaller Tablet as we did now)

- Having a more comfortable lounge chair for the child to lay in (2x)

- Having a smaller mask (2x)

- Having a bigger mask (2x)

- Give the participant more time to get used to the setting and measurement (1x)

- Start the measurement right away with no delays (1x)

BIA

- Have a faster device (3x)

- Most parents reported that this measurement was “just not possible” for their child

BOD POD

- Have distraction such as a video screen or buttons built into the BOD POD (4x)

- Have a more comfortable seat with a seatbelt (3x)

- Have relaxing music in the BOD POD (1x)