One alarming trend with respect to the obesity epidemic concerns the progressive rise of this chronic disease and its co-morbidities in children. Currently, up to 18% of this population is assigned an unhealthy weight condition, which is accompanied by adverse effects on the psychosocial and metabolic development, while simultaneously negatively affecting future adult health and functionality. Moreover, as childhood obesity proves highly resistant to current treatment strategies, this project launches personalized dietary intervention to support effective mediation of obesity in adolescents. To this end, state-of-the-art metabolomics and lipidomics will be employed to map individual fecal fingerprints of adolescents and gain new insights in the diet-obesity axis. Hereby, an unprecedented integration with the gut microbial composition and emotional stress will be established, with as key concept the gut-brain axis and involved neuroactive metabolites. Eventually, discovery of metabolite marker signatures and elucidation of mechanistic pathways will offer opportunities to stratify obese adolescents according to emotional stress status, microbial composition and dietary preferences, to establish personalized dietary recommendations on a macro-nutrient level. To substantiate the effectiveness of these metabolomics-based dietary interventions, the elaborated approach will be validated in a test population of metabolically characterized obese adolescents.