Metabolism refers to the body's mechanism through which it converts food into energy on a cellular level. It is carried out by thousands of enzymes, taking part in numerous interdependent metabolic pathways to perform this process. Metabolic diseases refer to diseases that disrupt the normal metabolism of a person. These diseases affect the capability of the cells to carry out crucial biochemical reactions, including the transport and processing of carbohydrates, lipids and proteins. The causes of metabolic diseases are usually hereditary. However, the majority of people affected with any metabolic disease may seem healthy for several months or years. The initial symptoms generally occur once the body's metabolism becomes stressed, such as during a febrile illness or after long fasting. These diseases can be treated through nutritional management if detected initially. This book aims to explain the diagnosis and treatment of metabolic diseases. It presents researches and studies performed by experts across the globe. This book will help new researchers by foregrounding their knowledge in this condition.