Investigators propose to pilot an adolescent obesity intervention, TEENS+, to examine the feasibility of this dietary intervention strategy and preliminary effectiveness of two models of parental involvement within adolescent obesity treatment.

Investigators will recruit overweight or obese adolescents (BMI >85th percentile) and parent(s) (BMI >25 kg/m2). Families will participate in one of two 6-month treatments: 1) TEENS+Parents as Coaches (PAC), engaging parents as helpers in their child's weight management, or 2) TEENS+Parent Weight Loss (PWL), engaging parents in their own weight management. All adolescents will participate in TEENS+, which includes behavioral support, nutrition education, and supervised physical activity.

For the adolescents, intervention will consist of weekly 1 hour exercise sessions and alternating weekly 1 hour behavioral and nutrition group sessions. Parents will also attend the nutrition sessions and participate in a behavioral parent-only biweekly group. Parent behavioral group sessions will be specific to the treatment arm (e.g. PAC or PWL). Assessments will consist of anthropometric measures, lab work, psychological surveys, and nutritional evaluations. Assessments will be completed at baseline, 3 months, 6 months (post-intervention), and 9 months.

Inclusion Criteria: Overweight (BMI ≥85% percentile for age and gender according to the CDC Growth Charts) males and females between the age of 12 and 17 years will be eligible for study participation. In order to be eligible, the adolescent must also reside with the primary participating parent, who has a BMI ≥25 kg/m 2 and is also willing to participate in the study protocol. Eligible families must live within a 30 mile radius of the Healthy Lifestyles Center (HLC) at Children's Hospital of Richmond (CHoR) at VCU where the interventions will be conducted.

Exclusion Criteria:

Adolescents and parents will be ineligible for study participation under the following conditions: 1) non-English speaking; 2) medical condition(s) that may be associated with unintentional weight change (e.g., hypothalamic injury, Prader-Willi, or malignancy); 3) diabetes mellitus diagnosed by history or a fasting glucose ≥126 mg/dl (subjects with glucose intolerance or "pre-diabetes" will eligible for study participation); 4) use of oral glucocorticoids, atypical antipsychotics, weight loss medications, or an investigational medication within 3 months of study participation; 5) medical condition(s) that may be negatively impacted by exercise; 6) physical limitation affected the ability to exercise, 7) psychiatric, cognitive or developmental conditions that would impair the adolescent's ability to complete assessments or participate in a group; 8) reports of compensatory behaviors (i.e., vomiting, laxative abuse, excessive exercise) in the past 3 months; 9) current pregnancy or plan to become pregnant during study period; 10) previous participation in TEENS or NOURISH; 11) current participation in another weight loss program; or 12) personal history of weight loss surgery.

Adolescents and parents taking metformin, oral contraceptives, tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), or stimulant medications may be eligible for participation; however, subjects must be on a stable dose of medication for at least 3 months prior to study participation.

In addition, adolescents will be excluded from participation (and referred for further evaluation) based on the results of baseline psychological assessments under the following circumstances: 1) clinically significant depression, evidenced by elevations (>20) on CDI; 2) suicidality as reported on CDI or during screening / behavioral interview; 3) psychosis, 4) clinical impairment in Activities of Daily Living and Functional Communication (i.e., expressive and receptive communication; and 3) clinically significant eating disorder based on EDE-Q.