Inflammation is normally a protective response that is part of the immune system’s reaction to infection. Chronic inflammation, on the other hand, is a sign that there is a breakdown in the immune response system, and leads to chronic inflammatory diseases. More and more researchers are finding evidence that associates low-grade chronic inflammation with metabolic dysfunction. Many metabolic disorders such as diabetes, atherosclerosis, ischemic heart disease, a variety of autoimmune diseases and other metabolic dysfunctions are linked to obesity, which is fast becoming a world-wide epidemic. These findings have been engendered by the increasing recognition and understanding of what has come to be called immunometabolism, the interplay between the two distinct disciplines of immunology and metabolism. Type 1 and type 2 diabetes are examples of disorders in which immunometabolism plays a role. The concept that autoreactive lymphocytes are involved in the destruction of β-islet cells in chronic autoimmune type 1 diabetes has been known for many years. More recently, the release of proinflammatory cytokines and the promotion of infiltrating macrophages into islet cells has emerged as a mechanism for the loss of β-islet cells in type 2 diabetes. Therefore, the detection of low-grade chronic inflammation and abnormal immunometabolism may assist in the identification of obese individuals who will be at risk for developing diabetes, cardiovascular disease, autoimmunity and other associated disorders.