FitLink: Improving Weight Loss Maintenance by Using Digital Data to Provide Support and Accountability

In a lifestyle modification program, contact with an interventionist (e.g., weight loss
coach) creates a sense of supportive accountability that can facilitate behavior change and
weight loss. Sustaining a strong sense of supportive accountability after face-to-face
intervention contact ends has the potential to improve outcomes during the notoriously
difficult weight loss maintenance period. One innovative way of facilitating supportive
accountability is providing participants with digital tools that objectively measure weight
and physical activity and track food intake in real-time, making the data from those tools
automatically and continuously available to coaches, and designing the timing and content of
intervention contacts such that they are responsive to the shared data. Although tools that
allow for data sharing from sensors and Internet-based applications are readily available,
the ways in which they are integrated into intervention contacts in a lifestyle modification
program are not yet optimized, and research has not systematically evaluated the effect of
data sharing on behavior. Overweight and obese participants (n = 90) will be recruited from
the community for a small randomized controlled trial in order to test the feasibility,
acceptability, efficacy, and mechanisms of action of a lifestyle modification intervention
enhanced with data sharing. In weeks 1-12 of the program (i.e., Phase I), all participants
will attend 12 weekly, face-to-face, group-based behavioral treatment sessions to induce
weight loss. Participants will be provided with a wireless body weight scale, physical
activity sensor, and digital food record app and instructed to use them daily use for
self-monitoring purposes. In Phase II (weeks 13-52), participants will be randomly assigned
to the standard (LM) or enhanced version of remote lifestyle modification (LM+SHARE). Neither
condition will have face-to-face intervention contact during Phase II; remote intervention
contact will consist of brief phone calls and text messages provided by the participant's
coach. Participants in both conditions will be prescribed continued daily use of the three
self-monitoring devices. In the standard LM condition, no digital data from these devices
will be directly shared with coaches; intervention encounters will be informed only by the
infrequent, delayed self-report of participants (which is the current standard of long-term
obesity care), and timing of text messages will be fixed. In LM+SHARE, the digital tools will
automatically and continuously transmit body weight, physical activity, and food record data
to the coach. In LM+SHARE, supportive accountability will be enhanced in three ways: 1)
participants will receive automated alerts after coaches view their data, 2) timing of
personalized text messages from coaches will be responsive to clinically notable change in
weight, physical activity, calorie intake, or use of scale, physical activity sensor, or food
record tool, and 3) content of the text messages and phone calls will be informed by the
digital data the coach has viewed, as well as the expectation that the coach will continue
viewing data in order to provide ongoing support. Assessments will be completed at 0, 12, 26,
and 52 weeks.

Inclusion Criteria:

- Adults aged 18-70 years with a BMI of 25-45 kg/m2 and weight <160 kg

- Access to a smartphone

- Satisfactory completion of all enrollment procedures

- Ability to engage in physical activity (i.e. can walk at least 2 blocks without
stopping for rest)

Exclusion Criteria:

- Medical condition (i.e. acute coronary syndrome, type 1 diabetes, renal failure) or
psychiatric condition (i.e. active substance abuse, eating disorder) that may:

- Pose a risk to the participant during the intervention

- Cause a change in weight

- Limit ability to comply with the behavioral recommendations of the program

- Pregnant or planning pregnancy in the next 1 year

- Planned move out of the Philadelphia area during the data collection period

- Use of a pacemaker (incompatible with wireless scale technology)

- Recently began or changed the dosage of a medication that can cause significant change
in weight

- History of bariatric surgery

- Weight loss of > 10% in the previous 3 months