Subject matter of the present invention is a method for predicting the risk of a subject for contracting diabetes mellitus and/or metabolic syndrome or for diagnosing metabolic syndrome in a subject wherein said subject is non-diabetic, comprising the following steps determining the level of pro-neurotensin or fragments thereof of at least 5 amino acids in a bodily fluid obtained from said subject; and correlating said level of pro-neurotensin or fragments thereof with the risk of said subject for contracting diabetes mellitus and/or metabolic syndrome, wherein an elevated level is predictive for an enhanced risk of getting diabetes mellitus and/or metabolic syndrome, or wherein an elevated level correlates to the diagnosis of metabolic syndrome in a subject wherein said subject is non-diabetic.