The ketogenic diet (KD), a well-established treatment for childhood epilepsy, is gradually gaining acceptance as a therapeutic modality for obesity and type 2 diabetes. The perception of ketone bodies as an unhealthy or “sinful” entity has led to concerns and doubts regarding the efficacy and safety of KD in physicians. This article describes the mechanism of action of KD and shares a pragmatic approach to its usage. It highlights the importance of predietary counseling, screening for indications/contraindications, and clinico-nutritional monitoring during therapy. Robust indications for KD are mentioned, to help place KD’s utility in the management of obesity and type 2 diabetes.