Personalized medicine is an evolving field and helps in detecting putative targets for pharmacological treatment modalities in obesity treatment. Obesity has become a pandemic and major threat, increasing all causes of mortality and bringing a heavy cost burden on health budgets. Although bariatric/metabolic surgery justified its role as the most effective treatment regimen for obesity and related comorbidities in the long-term, some patients require revisional operations, do not respond to this treatment option, or experience a relapse of their co-morbidities. For this reason, detection of possible non-responders and prediction of patients at high risk for developing cardiovascular or metabolic adverse events in long-term follow-up is of utmost importance. Therefore, the individualization of surgical treatment by the use of novel biomarkers has come into prominence recently. Many biomarkers and gene loci had been identified related to adiposity, insulin resistance, and oxidative stress. In this brief chapter, the recent advances and clinical implications of these biomarkers will be elaborated.