An Acceptance-Based Healthy Lifestyle Intervention for Diverse Adolescents

The goal of this clinical trial is to learn about cardiovascular disease risk among adolescent girls with overweight/obesity. The main questions this trial aims to answer are: 1. Does an acceptance-based healthy lifestyle intervention demonstrate more weight loss than a health education intervention? 2. Does an acceptance-based healthy lifestyle intervention show more improvements in participants' physiological, health-related, and psychological factors compared to a health education intervention? Participants in this trial will: 1. Engage in treatment for 6-months, comprising of a mixture of in-person and remote group sessions, occurring at Drexel University or over a video-conferencing platform. 2. Complete various assessments. These include self-reported questionnaires, measures of weight, height, body composition, blood pressure, and blood lipids, and wearing of smart watches to measure sleep and physical activity. Researchers will compare the acceptance-based and health education intervention groups to see if the acceptance-based treatment will indeed be effective in improving participants' health outcomes.

Inclusion Criteria: * Ages 14-19 * Gender identification as girl * BMI percentile ≥ 85th percentile for sex-and-age Exclusion Criteria: * Experience of weight loss of ≥5% of body weight in the past 6 months for any reason except post-partum weight loss * Having recently begun or changed the dosage of any medication known to affect appetite or body composition within the last 3 months * Plans to move out of the area within the next year * Active cancer or cancer requiring treatment in the past 2 years (except non-melanoma skin cancer) * Active or chronic infections (e.g., HIV or TB) * Active cardiovascular disease or event including hospitalization or therapeutic procedures for treatment of heart disease in the past 6 months * Active kidney disease * History of bariatric surgery * Lung disease: chronic obstructive airway disease requiring use of oxygen (e.g., emphysema or chronic bronchitis) * Diagnosed diabetes (type 1 or 2) * Any condition prohibiting physical activity * Diagnosis of an eating disorder * Have a mental handicap or are currently experiencing other severe psychopathology that would limit their ability to engage in the treatment program (e.g., severe depression, active psychotic disorder) * Recent or ongoing problem with drug abuse, alcohol abuse, or addiction * Currently pregnant or less than 3 months post-partum * Anticipation of a possible pregnancy in the next year * Unwillingness to report possible or confirmed pregnancies promptly during the course of the trial