Iterative Development of an Innovative Smartphone-Based Dietary Assessment Tool: Traqq

The developmental process of dietary assessment tools is often not only partially described, demonstrating the entire process underlying the scientific underpinning, and may benefit the development of comparable tools. This protocol describes all steps taken to develop the app, including an extensive screening of the literature and existing tools, followed by prototype building and evaluation by experts and intended end users. This protocol provides insights in the do's and don'ts of the developmental process of dietary assessment tools for nutritional research, as well as behavior change applications.

The development of a tool like Traqq requires the involvement of multiple experts, such as nutrition researchers, dieticians, and IT personnel. Be sure to keep these experts involved throughout the entire process. To manage a project in the manager role, navigate to traqq.idbit.

net and use the administrator credentials to log in to the backend of the application. Click Go to projects and click the arrow in the View column to select the desired project in the project. In the Project overview page, click the Participants tab.

When the participant overview screen appears, click Add new participant and enter the Codename, Notes, Login ID, and Login Key as appropriate and save the file. To schedule invitations for each participant, click on the Invitations tab. In the Invitations overview screen, click Add new invitation.

In the following screen, select a participant and enter the Period start time, Period end time, Opening time, Closing time, Survey URL, Notes, and enable as appropriate. To track the data collection via the Calendar tab, select a participant of interest from the dropdown menu. To track responses via the Response tab, select a participant of interest from the dropdown menu.

To analyze the collected data, send a request via email to the administrator for a data export. To use the application as a participant, download the freely-available app onto a smartphone and log in to access the app. After receiving an invitation, click the notification and click the open invitation.

To enter the food item consumed, click Add food item and enter the name of the consumed item. The name of the item can be clicked if it appears while typing. In the following screen, report the consumed amount, corresponding portion size description, eating occasion, and or time of consumption of the item.

After saving, repeat the entry until all of the consumed food items have been reported, then click Send list to submit the list. In this usability evaluation, a total of 22 subjects participated in think aloud interviews. Participants were between 22 and 70 years old, with a mean age of 48 years.

36%were men and over 50%were highly educated. The majority of the participants used an Android device, and almost all of the participants had over one year of experience with smartphone use. The evaluation of the system usability score indicated a mean rating of 79 out of 100, with a range between 40 and 100.

Only three participants rated the app below 68 and 13 rated it over 80, suggesting that the app can be considered user-friendly. Traqq is the first flexible dietary assessment tool for sharing the developmental protocol. We hope to assist and inspire fellow researchers who aim to develop similar flexible tools.