A low-grade inflammatory phenomenon is a feature of overweight and metabolic syndrome. The involvement of a pro-inflammatory Th17 lymphocyte subset and the CD69 + T regulatory (Treg) cell subtype in patients with metabolic dysfunction associated or not to overweight has not been fully elucidated. The aim of this study was to perform a quantitative and functional analysis of pathogenic Th17 lymphocytes and CD69 + Treg cells in patients with metabolic dysfunction (insulin resistance and dyslipidemia). The number of pathogenic Th17 cells and the levels and function of CD69 + Treg cells were analyzed in blood samples from individuals with metabolic dysfunction, associated or not to overweight. Pathogenic and non-pathogenic Th17 lymphocytes as well as Th22 cells were determined by eight-color flow cytometry analysis, whereas the levels and the suppressive function of CD69 + Treg cells were also analyzed by multiparametric flow cytometry. We detected increased levels of pro-inflammatory Th17 pathogenic cells and Th22 lymphocytes in overweight unhealthy individuals (p<0.001, compared to normal weight healthy). Conversely, diminished numbers of CD69 + Treg lymphocytes were observed in metabolically unhealthy individuals, with or without overweight. Likewise, the immunosuppressive function of CD69 + Treg cells was also defective in these patients. The increased levels of pathogenic Th17 cells along with a diminished number and function of CD69 + Treg lymphocytes may significantly contribute to the low-grade inflammatory phenomenon of metabolically unhealthy patients.