The present invention relates to a method for diagnosing a predisposition for diabetes comprising determining at least one metabolite in a test sample of a subject suspected to have a predisposition for diabetes and comparing said at least one metabolite to a reference, whereby a predisposition for diabetes is to be diagnosed. Moreover, the present invention encompasses a collection of metabolites, a data collection comprising characteristic values of metabolites and a storage medium comprising said data collection. Furthermore, the present invention also relates to a system comprising means for comparing characteristic values of metabolites of a sample operatively linked to a data storage medium. Further encompassed by the present invention are diagnostic means comprising at least one metabolite and the use of said at least one metabolite for the manufacture of diagnostic means for diagnosing a predisposition for diabetes. Finally, the present invention pertains to a method for identifying diabetes- related metabolites.