Charge: A Text Messaging-based Weight Loss Intervention

Charge: Optimizing a Standalone Text Messaging-Based Weight Loss Intervention

This study evaluates different versions of a text messaging-based app for weight loss. This study will place participants to 1 of 32 experimental conditions that reflect different texting components and levels. Participants will be randomized to a condition. The investigators will recruit 448 adults into a 6-month weight loss program, with an additional follow-up 6-months after the intervention ends.

Standalone text messaging-based weight loss treatments are scalable and can achieve population reach. However, these interventions are also modular; they can be delivered independently to maximize cost-effectiveness or combined with other approaches (e.g. provider counseling) to maximize outcomes. This study is a 12-month experimental trial among 448 adults with obesity. All participants will receive a core 6-month weight loss texting intervention that includes tailored behavior change goals, interactive self-monitoring, automated feedback, and skills training. Participants will be randomly assigned to 1 of 32 different experimental conditions.

Inclusion Criteria:

• males and females aged 18-65 years
• participants have English language proficiency
• participants have a BMI between 25-40 kg/m2
• Participants will own a smartphone
• Participants will be willing to receive multiple text messages daily.

Exclusion Criteria:

• prior or planned bariatric surgery
• psychiatric hospitalization in past 12 months
• pregnancy, nursing, or planned pregnancy
• history of a cardiovascular event
• history of an eating disorder
• history of a condition (e.g., end stage renal disease, cancer, schizophrenia) or use of medications (e.g., lithium, steroids, anti-psychotics) that would affect weight measurement, for which weight loss is contraindicated, or might promote weight change
• current participation in a weight loss trial and/or recent weight loss > 10%
• investigator discretion for safety reasons