Ketogenic Diet (KD) is defined as a diet of a high-fat and low-carbohydrate intake. It was first used in 1920 for managing epilepsy but it has gained its popularity because of its effect on weight loss. When a person consume less than 50g of carbohydrates per day, the body will begin 2 processes, gluconeogenesis and ketogenesis. Ketogenesis will induce ketosis, which is defined as an elevated serum levels of ketone bodies circulating in the blood. Nutritional ketosis is described by the levels of ketone levels of 0.5 - 3mmol/L. There are 4 major types of ketogenic diet, which are the Classic Ketogenic Diet (CKD), the Medium Chain Triglyceride Ketogenic Diet (MCTKD), the Modified Atkins Diet (MAD), and the Low Glycemic Index Treatment (LGIT). Before initiating KD, there are some contraindications that needs to be ruled out. KD interestingly thought to have some benefits in health condition, such as supporting weight loss, reducing Cardiovascular (CVD) risk, improving serum levels of patient with Type 2 Diabetes Mellitus (T2DM), and also considered as a therapeutic regiment for neurological disorder. However, there are also some evidences mentioning common side effects and concerns in KD, including the “keto flu”, kidney problems, disruptions in lipid metabolism, and its questionable adherence to maintain long stable weight loss.