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