Willis 2017.

Study characteristics
Methods	RCT
Participants	Participants: 70 adults with obesity (body mass index [BMI] = 30.0 kg/m2 to 5.0 kg/m2 ) (n = 70) Age range: 21–70 years Recruitment: participants were recruited using university broadcast emails, flyers, the General Medicine Clinic at the University of Kansas Medical Center and the wait list for participation in the Center for Physical Activity and Weight Management's Weight Control Research Projects. Potential participants were asked to contact study staff via phone or email. Interested individuals were directed to complete an initial eligibility questionnaire through Research Electronic Data Capture (REDCap) version 6.4.4 hosted at The University of Kansas Medical Center. Participants provided self‐reported height and weight (BMI), medication use, previous attempts at weight loss, presence of chronic disease, current physical activity level, and special diet restrictions. Eligibility: participants excluded if they were unable to participate in moderate intensity PA (i.e. walking), were regularly exercising (> 90 minutes/week) or at serious medical risk Country: USA
Interventions	Intervention: multi‐component (n = 34) Online social network intervention and Phone conference call sessions Control: non‐social media (n = 36) Phone conference call sessions 60‐minute group phone conference meetings of 12–18 participants were conducted one evening per week (total 24 meetings) for 6 months.
Outcomes	Weight loss at 6 months, waist circumference, dietary intake, physical activity
Equity	High‐income country. Adults with obesity
Notes	Health behaviours: physical activity and dietary intake were selected as both were reported as primary aims of the study. Body function: weight loss was considered the most patient‐important outcome for this category. Psychological health: not applicable. Well‐being: not applicable. Mortality: not applicable. Adverse effects: not applicable. Secondary outcomes: not applicable.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of personnel	High risk	Inability to blind health educators is reported as a limitation.
Blinding of participants	High risk	Inability to blind participants is reported as a limitation
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Overall blinding not reported ‐ some outcomes, e.g. daily step count are low risk because recorded by Fitbit, but weekly weight and diet were self‐reported by unblinded participants (high risk).
Incomplete outcome data (attrition bias) All outcomes	High risk	Reasons for missing data were not reported. Proportion of missing data was similar and greater than 80% retention at 6 months. Baseline data not provided for all participants
Selective reporting (reporting bias)	High risk	Additional outcomes reported in the paper not described in methods (e.g. quality of life, exercise self‐efficacy, moderators and mediators of diet and physical activity, changes in social support)
Baseline characteristics similar	Low risk	There were no baseline differences between participants.
Baseline outcome measurements similar	Low risk	No significant group differences were observed for BMI and waist circumference.
Protection against contamination	Unclear risk	Not reported