OUTCOME VARIABLES. Anthropometrical measures: Height, weight and waist-circumference, DXA-scans and bio-impedance measurements for determining the distribution of fat and muscle tissue. Physiological measures: Blood samples will be drawn in the morning after an overnight fast. Including measurements of total-cholesterol, HDL, LDL, TG, ASAT, ALAT, gamma-GT, bilirubin, creatinin, HbA1c and fasting insulin, c-peptide and glucose, TSH, fT4, CRP. Cortisol measurements from saliva and urine. Measurement of bloodpressure. Food records: The parents will be instructed to help their children to keep a diary of food and beverage intake for five days. They will use an electronic kitchen scale to weigh the food. Physical activity: Physical activity and sleep will be measured by using accelerometers. Psychological measures: The Child Behavior Checklist (CBCL) is a 138-item rating scale assessing behavioral and emotional symptoms in children/youth. Children's Depression Inventory (CDI). CDI is a 27-item self-report test assessing symptoms of depression in children (7-17 years). Self-Perception Profile for Children (SPPC). SPPC is a self-report measure of self-perception in children aged 8 to 14 years. The Dutch Eating Behavior Questionnaire Child version (DEBQ) is a measure of disturbed eating patterns in children and youth. The Youth Eating Disorder Examination-Questionnaire (YEDE-Q) is a self-reported measure of eating patterns and eating disorder psychopathology. OTHER MEASUREMENTS INCLUDED. The Parenting Scale (PS) is a 30-item questionnaire designed to measure different parental disciplines with children/youth. The scores on three sub-scales are calculated - Laxness, Overreactivity and Verbosity. The Barriers to Treatment Participation Scale (BTPS). The 44-item scale is developed and validated to address drop-out from treatment with out-patient psychological treatment of children and adolescents. Child and parent acceptability of the treatment will be measured by the FBSFT Acceptability Questionnaire.