Inclusion Criteria:

• * Overweight or obese (body mass index \[BMI\] \>= 27) but not heavier than BMI of 45.5 (measured by weight \& height)
• * Wants to lose weight in the next 30 days
• * Interested in learning skills to lose weight
• * Willing to be randomly assigned to either condition
• * Resides in United States (US)
• * Has daily access to their own phone and email
• * Does not have a medical or psychiatric condition that would limit their ability to comply with the behavioral recommendations of the program or pose a risk to the participant during weight loss, including meeting criteria for binge eating disorder, and meeting criteria for severe depression (CESD \>= 25), or a diagnosis of serious heart disease, diabetes, uncontrolled hypertension, or cancer without written confirmation of approval from their physician office
• * Not pregnant, planning to become pregnant or breastfeeding in the next 12 months
• * In the past 3 months changed the dosage of prescription medications that can cause a significant change in weight or appetite
• * Have not lost more than 5% of their weight in the past 6 months
• * Willing and able to read in English
• * Not participating in or planning to participate in other weight loss programs
• * Has not participated in our other ACT intervention studies
• * Does not meet criteria for combined heavy plus binge drinking
• * Has access to a Bluetooth-enabled device and Wi-Fi and/or data plan
• * Is not planning to have or has not recently had (past 12 months) bariatric surgery
• * For outcome data retention, eligibility criteria included: Willing to complete follow-up surveys, and provide email, phone, and mailing address

Exclusion Criteria:

• * The reverse of the inclusion criteria