Ecological Momentary Assessment of Eating Behavior in Overweight Youth

Interested individuals will be screened via phone for initial study eligibility. Potentially
eligible participants and their parents will attend an in-person screening at the University
of Chicago in which they will complete assent and consent procedures. Youth will have their
height and weight measured and complete interviews to assess eating disorder symptoms and
psychiatric comorbidities. Eligible participants and parents will then complete self- and
parent-report assessments of eating behavior, body image concerns, psychiatric symptoms, and
interpersonal functioning. Participants will then be trained on how to complete the EMA
recordings.

A one-day practice period during which adherence is ≥70% of ratings will qualify children to
initiate the 14-day EMA study period; these data will not be used in statistical analyses to
reduce concerns about the effect of immediate reactivity to self-monitoring. Youth will
self-monitor on a smartphone or other wireless device through the use of the ReTAINE
(Real-Time Assessment in the Natural Environment) system. ReTAINE™ is a secure, web-based
system that allows for momentary data to be collected through a wide variety of portable
devices. Youth may use their own smartphone/wireless device or one provided by the study
team. Recent survey data suggest that up to 80% of children and adolescents have access to
the Internet through a cellular phone or other wireless device, indicating that this
approach is reasonable in this age group. EMA protocols have been completed with good
compliance in youth.

The proposed study will include three types of EMA signaling methods.63 First, participants
will be signaled at 3-5 semi-random times throughout the day (signal-contingent) to report
on current affect, stressors, interpersonal functioning, and to report any eating episode
that has not been previously recorded. These signals will occur at random times between
7:00-8:00am, 3:00-4:00pm, and 6:00-7:00pm on weekdays, so as not to interfere with the
school day; and between 8:00-9:00am, 11:00am-12:00pm, 2:00-3:00pm, 5:00-6:00pm, and
8:00-9:00pm on weekend days. In addition, participants will be instructed to complete
momentary ratings of affect, stressors, interpersonal functioning, and a variety of
physiological, environmental, cognitive, and behavioral factors associated with eating as
soon after each eating episode as possible (event-contingent). Event-contingent ratings will
allow for the assessment of immediate consequences of eating that may be missed by the
random signals. Finally, participants will complete ratings of affect, stressors,
interpersonal functioning, and physiological, environmental, cognitive, and behavioral
factors at the end of each day (interval-contingent) to capture any changes since the last
random signal. This combination of signal-, event-, and interval- contingent recordings has
been successfully implemented in previous EMA studies of overweight youth.

Participants will be contacted by phone after the first day of EMA recording, at which point
they will be given feedback regarding their compliance rates, and any questions or concerns
regarding assessment procedures will be discussed with a research assistant. Throughout the
14-day assessment period, we will also attempt to contact participants via telephone at
least twice per week to check in with them regarding any problems or concerns. This approach
has demonstrated success in participant retention and validated compliance during a previous
research study which required daily collection of saliva samples and interval ratings of
mood and disordered eating behaviors over 35 days.

Complementary to the collection of EMA data, Nutritional Data System for Research (NDS-R)65
will be used to compile nutritional intake data on eating episodes reported by participants
through the ReTAINE system. Two weekdays and one weekend day during the 14-day protocol will
be randomly selected for each participant, during which the participant will be contacted by
phone and asked to recall the details of each of that day's eating episodes. The time points
of each eating episode will be entered into the NDS-R system, and the nutritional data of
interest will be merged with the EMA data in order to assess contextual factors associated
with specific dietary patterns (e.g., consumption of high fat meals). ActiGraph watches
(GT3X) will be worn by participants for the duration of the 14-day protocol to compile data
on sleep patterns in the natural home environment. These computerized wristwatch-like
devices collect data generated by movement and are minimally invasive. Participants' parents
will also complete 14-day sleep diaries in which they will record their children's bedtime
and wake time, which will provide the start and end times for actigraphy analyses.

At the completion of the daily assessment phase, participants will return to the University
of Chicago to return the loaner smartphone, if applicable; complete a brief, final
assessment; and receive their final study incentive payments. The final assessment will
include a modified version of the Child Eating Disorder Examination (ChEDE) interview to
cover the previous two weeks during which EMA was conducted. This assessment will be used to
determine changes in symptom frequency (i.e., reactivity to study procedures).

Inclusion Criteria:

Participants be included if they are overweight or obese (BMI≥85th %ile) and aged 8-14
years.

Exclusion Criteria:

Participants will be excluded if they 1) are currently taking any medications known to
affect weight or appetite (e.g., antidepressants, steroids, chemotherapy drugs); 2) have a
current or past diagnosis of an eating disorder involving purging or suppressed body
weight (e.g., bulimia nervosa or anorexia nervosa); 3) are unable to read and understand
English fluently; or 4) are receiving concurrent treatment for obesity.