Mind Your Step is one of Lifelines' additional assessments.
This assessment was a collaboration between Lifelines and the Hanze University of Applied sciences, Research group Healthy Ageing.
The first goal of the assessment was to gain insight in determinants related to the adoption of two quantified self-devices: a digital weight scale and an activity tracker which could also measure sleeping behavior.
The second goal was to assess to what extent a change in self-regulation capabilities can explain weight loss after 4 and 12 months of self-tracking.

The project took place between April 2016 and April 2017.
Participants (>25 years old) were invited to use a digital weight scale and an activity tracker. The devices were connected to a smartphone application, in which the user could see his or her own data and changes in these data over time.
All of the participants participated in the study for one year. They filled out a digital questionnaire at the beginning of the study, after 4 months, and after 12 months. One questionnaire included possible determinants for adoption and effect of self-tracking devices (like personal variables, self-regulation for health, and motivation towards self-tracking).
In addition, participants were asked to fill out an evaluation questionnaire about the usage, effect, and experience with the devices.

There was a restriction on number of participants because there were 100 activity trackers available.

700 participants between 25 and 65 years old were invited to be screened for participation. 95 participants were included in the final study.

The response rate:

• 85% (n=80) filled out the baseline questionnaire and installed both devices
• 77% (n=73) completed T1 questionnaire (after 4 months)
• 62% (n=46) completed T2 evaluation questionnaire (after 12 months)

The questionnaires included questions about intention to start with self-tracking, and intention to change weight, sleeping behavior and physical activity behavior. In addition, attitude, self-efficacy and social norm towards self-tracking, self-regulation for health and perceived health were measured.
Weight and self-weighing frequency were calculated using the weight self-measurements the participants conducted.
After 4 and 12 months of self-tracking, the participants filled out an evaluation questionnaire in which they could indicate their experiences with the devices, and whether they had changed their physical activity behavior and eating habits.

Most participants were satisfied with the self-tracking devices, although the usage of the devices declined over time. Usage of the weight scale stabilized after 3 months of self-tracking.
The Pulse activity tracker gave some technical problems, like a short battery life, and was therefore replaced until 6 months after the start of the study in at least 30 participants. Thereafter, no replacement was possible due to a restricted availability of the tracker.
About 40% of the participants indicated to have changed their eating habits, and 60% indicated to have increased their physical activity behavior.
On average, the participants lost 2 kg after 4 months, which was remained after 12 months. An increase in self-regulation capabilities (goal-orientation after 4 months and decision-making after 12 months) explained this weight loss, next to intention to change weight and self-weighing frequency.

• Kooijman, TJM et al. (2020) The role of self-regulation in the effect of self-tracking of physical activity and weight on BMI. Journal of Technology in Behavioral Science (in press).