To determine whether reducing loss of control eating (LOC) with Interpersonal Psychotherapy-Weight Gain (IPT-WG) will be effective for adolescent military-dependents who report such behavior. The investigators will examine whether IPT-WG influences body weight gain trajectories and prevents worsening disordered eating, psychosocial problems, and metabolic functioning among military dependents at heightened risk for adult obesity and disordered eating. This study will provide key efficacy data for a new promising obesity prevention program for youth from military families.

The prevalence of overweight among military personnel and their dependents is at a rate similar to that of the civilian population. Nearly 30% of adolescent dependents are overweight, including approximately 15-17% who are obese, placing them at high risk for impairments in metabolic functioning, type 2 diabetes, and adult obesity. Youth who are overweight (body mass index, kg/m2, BMI ≥ 85th percentile) are at high risk for excess weight gain as they grow. Since effective weight loss and maintenance treatments are rare, prevention may be the most important approach to reducing the high prevalence of obesity. To date, most pediatric obesity prevention programs have been met with limited success. To address those at greatest risk for obesity, more targeted approaches may be required. There is a need to reduce prospectively identified risk factors in order to prevent excess weight gain in youth at high risk for adult obesity. The most common disordered eating behavior among overweight adolescents is loss of control (LOC) eating, during which the feeling of being unable to stop eating is experienced. LOC eating predisposes youth to gain excessive weight and fat. Thus, LOC eating is likely to be an important contributor to obesity in susceptible individuals. Decreasing LOC in adolescents may prevent excess weight gain. Investigators at the Uniformed Services University of the Health Sciences (USUHS) is in partnership with Ft. Belvoir Community Hospital (FBCH) and Walter Reed National Military Medical Center (WRNMMC) to test the effectiveness of IPT-WG to slow the trajectory of weight gain in overweight adolescent boys and girls who report LOC and prevent worsening disordered eating and metabolic functioning. The unique stress burdening the children of military personnel while the country is at war suggests that obesity prevention programs targeting interpersonal stress and promoting positive social functioning may be especially timely in this population. It is hypothesized that IPT-WG will decrease LOC eating and related eating behaviors and, in turn, prevent excess weight gain and the development of exacerbated disordered eating in adolescent children of military personnel. Secondary to the prevention of excess weight gain, youth will experience improvements in metabolic functioning.

Adolescent Inclusion Criteria:

1. Age between 12 and 17 years (at the start of the study)
2. BMI at or above the 85th percentile for age and sex
3. English-speaking
4. Ability to complete study procedures, including the ability to participate in a group
5. > 1 episode of LOC eating during the 3 months prior to assessment
6. Must have a parent(s) enrolled in TRICARE at the time of study initiation

Parent Inclusion Criteria:

1.The consenting parent or caregiver must be able to comprehend English.

Adolescent Exclusion Criteria:

1. Presence of a chronic major medical illness: renal, hepatic, gastrointestinal, endocrinologic (e.g., Cushing syndrome, hyper- or hypothyroidism), hematological problems or pulmonary disorders (other than asthma not requiring continuous medication).
2. Presence of a documented, obesity-related medical complication that would require a more aggressive weight loss intervention approach: type 2 diabetes, hyperlipidemia, hypertension, fasting hyperglycemia, or nonalcoholic steatohepatitis.
3. Self-reported current pregnancy, current breast-feeding, or recently pregnant girls (within 1 year of delivery).
4. Current, regular use of prescription medications that affect appetite, mood, or body weight: currently prescribed SSRI's, neuroleptics, tricyclics, stimulants, or any other medication known to affect appetite, mood, or body weight. For girls, oral contraceptive use will be permitted, provided the contraceptive has been used for at least two months before starting the prevention groups. Medication use for non-serious conditions (e.g., acne) will be considered on a case-by-case basis.
5. Current involvement in psychotherapy or a structured weight loss program.
6. Weight loss during the past two months for any reason exceeding 3% of body weight.
7. Current anorexia nervosa or bulimia nervosa as determined by documented medical history or if uncovered during K-SADS semi-structured interview. Current binge eating disorder (BED) will be permitted, although adolescents will be informed that they have an eating disorder and have the option to participate in the study or seek outside treatment (and not participate in the study).
8. Individuals who have major depressive disorder, psychoses, current substance or alcohol abuse, conduct disorder, as determined by Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS) semi-structured interview and as defined by criteria outlined in the DSM-5, or any other DSM psychiatric disorder that, in the opinion of the investigators, would impede competence or compliance or possibly hinder completion of the study.

Parent Exclusion Criteria:

1. None