This study aims to test two strategies for weight loss. Participants will be randomly assigned to one of the two 4-week weight loss programs: (1) a behavioral weight loss program that involves recording weekly weight, physical activity, and caloric intake plus daily exercises in which information about a healthy lifestyle is reviewed or (2) a behavioral weight loss program that involves recording weekly weight, physical activity, and caloric intake plus daily exercises in which descriptions of positive future events are reviewed. Throughout the study, participants will complete assessments that examine the effects of the interventions on delay discounting, physical activity, weight, and other important health and psychosocial outcomes.

Inclusion Criteria:

• Age between 18-70
• Body Mass Index between 30-50
• English Speaking
• Have a smartphone that can be used for study activities

Exclusion Criteria:

• Report being unable to walk 2 blocks without stopping
• Are currently participating in weight loss treatment, have a history of bariatric surgery, or lost ≥5% in the past 6-months
• Are pregnant or plan to become pregnant within 2 months
• Report a heart condition, chest pain during periods of rest or activity, or loss of consciousness on the Physical Activity Readiness Questionnaire
• Report a medical condition that could jeopardize their safety in a weight control program with diet and exercise guidelines
• History of or current traumatic brain injury, dementia or Alzheimer's disease; a history of Multiple Sclerosis, or other neurological disorders
• Report conditions that, in the judgment of the PI, would render them unlikely to follow the protocol (e.g., relocation, dementia, unable to read and write in English)
• Have no Internet access or unwilling to use personal smartphone for study.