Diabetes mellitus is one of the most serious heterogeneous endocrinologic diseases; more than 90% of those given this diagnosis have type 2 diabetes mellitus, usually accompanied by macrovascular and microvascular complications. Because most cases include a 7- to 10-y latency period before disease onset, however, it is of vital importance that more powerful and practical approaches be developed for early diagnosis and improved prevention and treatment. Metabonomics is a powerful new approach that is especially useful for the treatment of patients with metabolic diseases because it can evaluate the holistic responses of the body to any subtle perturbation with the use of advanced analytical apparatus and chemometric methods that have been applied in the diagnosis and evaluation of type 2 diabetes mellitus. It is a promising approach to the study of complex diseases that should prove useful in the future, along with other -omics techniques performed in the context of systems biology.