The objective of the proposed study was to test the usability, acceptability, and
preliminary efficacy of a digital dietary self-monitoring (dDSM) log that used positive
reinforcement strategies (caregiver praise and gamification) to improve child engagement
in DSM.
For this proof of concept trial, a mobile-optimized, web-based dDSM log was developed to
test the two positive reinforcement strategies: caregiver praise and gamification. The
dDSM log was developed as a mobile-optimized website, rather than an app, so that phone
operating systems were not a limitation of use. Families were therefore able to access
the dDSM log from a computer, smartphone, or other internet-enabled device. All dDSM logs
included three basic features: 1) the ability to log targeted food groups with amounts
and servings consumed, 2) the ability to indicate logging was complete for the day, and
3) access to a help feature that provided guidance on tracking and serving sizes.
Children were instructed to self-monitor their daily intake of the following food groups:
fruits, vegetables, sweet and salty snack foods, and sugar-sweetened beverages (SSBs).
DSM focused on these four food groups because they had an established influence on
health. Fruit and vegetable consumption was associated with a decreased risk of chronic
disease, and reduced consumption of energy-dense foods like sweet and salty snacks and
SSBs was recommended for weight loss in children. Additionally, these food groups were
frequently targeted in childhood obesity treatment and were easily understood by young
children.
Using a 2x2 factorial design, each child-caregiver dyad was randomly assigned to 1 of 4
conditions: BASIC, PRAISE, GAME, or PRAISE+GAME. Each child was provided a unique URL to
access a personal dDSM log with the appropriate, randomly assigned features (praise
and/or gamification). For PRAISE and PRAISE+GAME conditions, caregivers were instructed
to provide daily process praise to their child related to DSM behaviors. While DSM was
frequently implemented within treatment, children in the proposed study engaged in DSM
without a concurrent intervention to tightly control the influence of the independent
variables on DSM behaviors only (as compared to having all adult caregivers learn how to
praise or having caregivers focus their praise on achieving dietary goals, which were
both standard components of family-based childhood obesity interventions). Thus, only
caregivers randomized to PRAISE or PRAISE+GAME were instructed on praise and, in the
absence of dietary goals for intervention, caregivers had only one behavior (DSM) to
praise. For GAME and PRAISE+GAME conditions, logs integrated three game mechanics:
points, levels, and a virtual pet. Points were accumulated for engaging in DSM behaviors,
and the accrual of points evolved a virtual pet over time, acting as a digital token
economy. The number of points to level up increased with each level, so that each
consecutive level was harder to attain than the previous one. At the end of the 4-week
DSM period, families who completed follow-up assessments received two $25 gift cards (one
for the caregiver, one for the child) and were provided access to a short online
behavioral nutrition education program.
The primary DSM outcomes were frequency (i.e., the number of days any food/beverage item
was tracked or logging was marked complete) and timing (i.e., how many sessions of
recording were completed each day and whether foods/beverages were logged on the day of
intake). On days in which no targeted food group was consumed, children had the ability
to mark logging as complete for the day (Figure 1a). Indicating logging was complete in
the absence of any tracked foods was considered a "tracked" day. Pre-post changes in
intrinsic motivation were also examined.
