In a 24-week trial, 120 participants from both urban (n = 60) and rural (n = 60) areas
will be assigned receive either remotely delivered episodic future thinking or a control
condition. Participants will be prompted three times daily to engage in episodic future
thinking or control thinking. All participants will also receive virtual diet and
physical activity support; self-monitoring of diet, activity, and weight; and case
management. Outcome measures will be assessed at baseline, 8 weeks, and 24 weeks.
In the week following informed consent, participants will complete remote assessments of
dietary intake (ASA-24 food recalls) and self-reported physical activity (IPAQ-SF), as
well as self-administered survey (requiring approximately 10 minutes) to obtain
sociodemographic information and delay discounting measures.
The week following baseline, all participants will begin phone-based case management;
online self-monitoring of diet, activity, and weight; and diet and activity support.
Beginning in Week 3, participants will begin episodic future thinking or control thinking
conditions. Here, participants assigned to the EFT group will complete an episodic event
generation task to generate a number of positive, vivid events that may occur at several
time frames in the future (1 month, 3 months, 6 months, 1 year, 3 years, 5 years, and 10
years; a total of 7 events). During this task, participants will also generate
corresponding short text descriptions that will be used as cues to prompt episodic
thinking in the natural environment. Participants will regenerate all cues during weeks
8, 16, and 24, with partial regenerations (regenerating only the 1 month and 3 month
cues) scheduled during weeks 12 and 20. Participants will complete delay discounting
tasks while viewing and imagining their EFT or HIT cues in weeks 3 and 16.
On the day following the event/cue generation, participants will begin thrice-daily
smartphone app prompts to engage in EFT. In each prompt, participants will be presented
with one of their EFT cues, chosen randomly, and asked to read and vividly imagine this
event for a period of 30-60 seconds in a quiet location.
In contrast to the EFT condition, the control condition will be healthy information
thinking (HIT). Specifically, participants assigned to the HIT group will be asked to
read informational health vignettes on various topics related to T2D and health, adapted
from publicly available information (e.g., information on the role of insulin and insulin
resistance in T2D, nutrition labeling, understanding T2D risk factors). Participants will
then be asked to describe, in 1-2 sentences, a specific piece of information they learned
about each topic. This process is designed to mimic the event generation task used for
the EFT group, with the number of topics matched to the number of future EFT events.
Beginning in Week 3, participants will receive smartphone prompts to read and consider
their self-generated topic descriptions with the same frequency and at approximately the
same times of day as the EFT group. Moreover, HIT participants will regenerate these
descriptions with the same frequency as the EFT group.
At Weeks 8 and 24, participants will complete the same primary and secondary outcome
measures they completed during the baseline week, including delay discounting, BMI, and
HbA1c.
In addition, during a debriefing stage after Week 24, participants will also rate the
perceived helpfulness and convenience of each intervention component (EFT/control
prompting, diet and activity support, self-monitoring, and case management) and remote
outcomes assessment methods.
