Parent Supported Weight Reduction in Down Syndrome

Inclusion Criteria: * Age 13-26 with Down syndrome * Living at home in single- or two-parent family, w/no plans to leave home in next year * Achieves IQ score 45 or above on the Kaufman Brief Intelligence Test (K-BIT) * Academic ability and necessary behavioral/social control to participate in a group classroom-based educational program * Clinically overweight, as indicated by a BMI at or above 85th percentile for age and gender * Signed approval to participate, which includes a completed recent thyroid screen, provided by participant's Primary Physician (and participant's cardiologist is he/she has a history of a heart condition), and participant's neurologist if he/she has a history of seizures) Exclusion Criteria: * Untreated thyroid disorder * Type I or II Diabetes * Cardiac problem, treated or untreated, for whom the participant's treating cardiologist indicates restrictions in physical activity * Epilepsy/seizure disorder in which participant is not stable on medications * Orthopedic injuries or deformities * Chronic GI illness (except constipation) including inflammatory bowel diseases and celiac disease * Prader Willi syndrome * Unwillingness to wear accelerometer at screening or enrollment * Non-ambulatory, i.e., uses wheelchair or other assistive devices for moving about and walking * Chronic/severe foot infection (as screened by physical therapist, but in coordination with physician) * Severe balance problems (as screened by physical therapist) * Resting heart rate less than 50 beats per minute (bpm), or greater to or equal to 100 bpm (observed in physical therapy screening) * History of major medical illness (i.e., cancer, leukemia) * History of profound behavioral problems, i.e., self injury, injury to others, property destruction, etc. * Other diagnosed disorders, including autism spectrum disorders, bipolar disorder (within the last year), eating disorder (within the last year), major depression (within the last year), psychosis \& schizophrenia * Other exclusion conditions left to the discretion of the study team