The purpose of this study is to examine whether the addition of online yoga classes, compared to health and wellness classes, can improve the amount of weight loss produced from an Internet-based weight loss program. All individuals will receive a 12-month, automated Internet-based weight loss program. Following 3 months of of weight loss treatment, individuals will be randomized to also receive yoga classes or health and wellness classes for 9 months. Assessments will occur at baseline, 3, 6, 12, and 18 months and will include measures of weight, eating behaviors, physical activity, and psychosocial factors.

All individuals enrolled in this study will receive a 12-month Internet-based weight loss program, consisting of a 3-month weight loss program, followed by a 9-month weight loss maintenance program. Each week during the first 3 months individuals will be asked to view a 10 to 15-minute multi-media lesson. These lessons focus on behavioral principles for changing diet and physical activity behaviors. Participants are also given weight loss, calorie intake, and physical activity goals. They are taught how to self-monitor this information and are instructed to submit it weekly on the study website. Automated, weekly individualized feedback is provided. Following the 3-month weight loss program participants will receive a 9-month weight loss maintenance program. During this time, they will be asked to view monthly video lessons which focus on strategies for successful weight loss maintenance and be instructed to continue to self-monitor weight, calorie intake, and physical activity minutes on the study website. Automated, monthly feedback is provided.

In addition, participants completing the 3-month weight loss program will be randomly assigned to receive either 9 months of Iyengar yoga classes or 9 months of health and wellness classes. These classes will be held twice per week (live via Zoom) for 14 weeks and then once per week thereafter.

To evaluate the program, participants are asked to complete assessments prior to starting the program (baseline) and at 3, 6, 12 (post-treatment), and 18 months (6 months after completion of the program). For these assessments, participants will be asked to weigh themselves on their study scale, complete a series of online surveys, wear a physical activity monitor for 10 days, and answer daily surveys on their smartphone for 10 days.

Inclusion Criteria:

• BMI: 25-40 kg/m2
• Must own smartphone and have daily, home Internet access

Exclusion Criteria:

• Currently pregnant, planning to become pregnant within the next 18 months, or pregnant within the past 6 months
• Current or recent enrollment (<2 years) in a weight loss program
• Current or recent yoga, meditation, or mindfulness practice, either at home or in a studio (defined as ≥12 sessions within the past 2 years)
• Presence of any medical condition for which yoga, exercise, weight loss, or dietary restriction is not recommended
• Recent weight loss (≥10 pounds within the past 6 months)
• Currently taking weight loss medications
• History of bariatric surgery
• Inability to walk 2 blocks without stopping
• Baseline smartphone survey completion rate <80%

Data will available to other researchers as raw individual-level data; however, this will not be available until the primary outcome papers from the study are accepted for publication. Requestors will be required to sign a data sharing agreement stating that: (1) They will use the data for research purposes only unless otherwise agreed, and will not identify any individual or personal information, (2) Data will be secured using appropriate technology/firewalls, (3) Data will be destroyed after data analysis, and (4) They will cite data appropriately in publications or other written materials. A record of transfer of data and a copy of the dataset that was distributed will be kept by The Miriam Hospital

Study data will be made available as soon as possible, but no later than within one year of the completion of the funded project period or upon acceptance of the data for publication.