Personalizing Financial Incentives

In this study, community outpatients will participate in a clinician-facilitated, group-based behavioral weight-loss program for 24 weeks. Dietary self-monitoring data (input by patients via a mobile phone dietary application) and weight data (input by patients via cellular scale) will be collected by a software platform. A reinforcement learning algorithm will use data collected during the trial to predict which participants will respond to a financial incentive. Incentives will be provided to participants predicted to respond, and they will be notified of incentives via text messaging.

Inclusion criteria

• Willing to attend virtual baseline and follow-up data collection visits
• At least 18 years of age
• Verified obesity as defined as a BMI ≥30 kg/m2
• Agree to attend 13 biweekly group classes (virtual) delivered by a registered dietitian
• Agree to review study materials between classes
• Regular access to an unshared smart phone
• Reliable access to internet
• Able to speak and read English
• Desire to lose weight
• Able to connect to a video conference call using a smartphone, tablet or computer with a webcam and microphone
• Ability to download and use Fitbit app daily
• Have or be willing to create a Gmail address
• Physical ability to stand on a scale without support

Exclusion criteria

• Weight loss of at least 10lbs in the month prior to screening
• Weight > 380lbs
• Currently enrolled or enrolled in the previous month in a clinical, research, or community program focusing on lifestyle change that could affect weight
• New user of weight loss medication
• Pregnant, lactating or planning on becoming pregnant during the study
• History of bariatric procedure or planning to have bariatric procedure in the study timeframe
• Residing in a nursing home, skilled nursing facility or assisted living facility
• Impaired hearing
• Significant dementia, drug or alcohol abuse, or unstable psychiatric illness (e.g., schizophrenia, psychosis)
• Current treatment for cancer or being treated for cancer (besides basal cell carcinoma or squamous cell) in the last 6 months
• Use of insulin, sulfonylureas, or meglitinides due to increased risk for hypoglycemia
• Diuretic medication doses higher than hydrochlorothiazide or chlorthalidone 25 mg daily, furosemide 40 mg daily, torsemide 20 mg daily, bumetanide 1 mg daily, or any use of metolazone; use of potassium-sparing diuretics is acceptable
• Unstable heart disease in the 6 months prior to screening
• Chronic kidney disease at stage 4 or higher
• Exertional chest pain
• Pain, fainting, or other conditions that prohibit mild/moderate exercise
• History of ascites requiring paracentesis
• Inducing vomiting to prevent weight gain or counteract the effects of eating an average of 1 time per week or more in the past 3 months*
• Not suitable for study participation due to other reasons at the discretion of the investigators