In a pilot randomized trial of 160 obese participants, investigators will test the feasibility of a behavioral weight loss program delivered entirely via Facebook. We will recruit in 2 separate waves of 80 participants each. Participants will be randomized to: 1) a condition with study participants only or 2) to a condition they will be able to invite their friends into (wave 1) or one in which the study team keeps recruitment open to allow enrollment through week 8 (wave 2). All participants will receive behavioral counseling via the private Facebook group from the coaches who are present on the network daily. Participants will track their diet and exercise via a free commercial mobile app.

The overarching goal of the research plan is to test ways to leverage mobile technologies and social media to increase the impact, scalability, cost-effectiveness, and dissemination potential of lifestyle interventions that reduce cardiovascular disease (CVD) risk. Mobile technology and social media have the potential to reduce the intensity of traditional prevention interventions and enhance outcome by delivering behavioral strategies in-the-moment and by connecting patients other patients to generate better communication and a social support system for lifestyle changes.

This study includes a behavioral weight loss program delivered entirely via on online social network. The weight loss intervention is based on the Diabetes Prevention Program (DPP), an evidence-based weight loss program focused on lifestyle changes. The goals for the intervention are 175 minutes of moderate physical activity per week and an overall weight loss of 7%. Each participant will get an individualized calorie goal that would facilitate a 1-2 lbs. weight loss weekly. Participants will be connected to one another via Facebook and receive behavioral counseling via posts from coaches who are present on the network daily. Participants will track their diet and exercise via a free commercial mobile app. Participants will be assigned to either a Facebook group allowing the invite of friends (wave 1), a Facebook group with open enrollment through week 8 (wave 2) or a Facebook group including only study participants. If they are assigned to the group including their friends, they have the opportunity to invite their friends to participate in the weight loss group if they are interested in losing weight as well. They will not have a limit as to how many friends they can invite. The friends that are invited will not undergo the same procedures as the Facebook (FB)+friends study participants, but we will provide them with a factsheet and collect minimal information from them. If they are assigned to the group with open enrollment through week 8, additional people will be recruited into that group. Those participants being enrolled between week 1-8 will undergo the same procedures as others besides randomization. The goal of both of these studies is to explore how to build the size of online weight loss groups in such a way that increases participant engagement. Feasibility outcomes include engagement (frequency of posts, likes, and comments and number of completed days of tracking posted) retention, acceptability, and weight loss. Post intervention focus groups will gather feedback on the program.

Inclusion Criteria:

Participants must be:

1. 18-65 years of age;
2. Have a BMI 27-45 kg/m²;
3. Lives in the United States; and
4. Have daily internet access;

Exclusion Criteria:

1. Does not post on Facebook at least once per week
2. Comments on someone else's post on Facebook less than once per week
3. Does not currently use a smartphone;
4. Is not familiar with using phone apps;
5. Pregnant and/or lactating;
6. Meets criteria for severe depression on the Patient Health Questionnaire (PHQ-9) (score of >20);
7. Had bariatric surgery, plans to during the study;
8. Has had a weight loss of 5% or greater within previous 3 months;
9. Meets criteria for Binge Eating Disorder;
10. Condition that precludes lifestyle changes (i.e. a condition that prevents physical activity increase or dietary changes);
11. Medications affecting weight;
12. Incapable of walking ¼ mile without stopping;
13. Type 1 or 2 diabetes;
14. Participated in previous weight loss studies under the PI;
15. Has concerns about being in a Facebook group with other faculty, staff, or students from the University of Connecticut;
16. Has concerns about being audiotaped;
17. Inability to provide consent;
18. Prisoners; and
19. Non-English speaking

Wave 2 Randomized Sample

Adverse events were collected over the period of 16 weeks.

Adverse events were assessed during follow-up as well as documented when participants reported them during the intervention. Pregnancy was only assessed with female participants.