Method for the prognosis of obesity and/or the prognosis and/or diagnosis of diabetes, comprising the steps: a) providing a sample of adipose tissue from a donor, b) determining the gene expression level of the genes for HMGA2 and PPAR-gamma in the sample and c) classing the donor of the sample into one of at least four risk groups taking into account the gene expression levels of the genes for HMGA2 and PPAR-gamma in the sample and the body fat percentage, in particular the BMI of the donor, wherein the classification is done into one of the groups selected from the group consisting of a) elevated relative gene expression level for HMGA2, reduced relative gene expression level for PPAR-gamma and elevated body fat percentage, in particular average BMI ≥ 25, b) reduced relative gene expression level for HMGA2, reduced relative gene expression level for PPAR-gamma and elevated body fat percentage, in particular average BMI ≥ 25, c) reduced relative gene expression level for HMGA2, reduced gene expression level for PPAR-gamma and non-elevated body fat percentage, in particular average BMI < 25, d) reduced relative gene expression level for HMGA2, elevated relative gene expression level for PPAR-gamma and non-elevated body fat percentage, in particular average BMI < 25, wherein the provision in step a) is done such that the method is not a diagnostic method performed on the human or animal body. a) providing a sample of adipose tissue from a donor, b) determining the gene expression level of the genes for HMGA2 and PPAR-gamma in the sample and c) classing the donor of the sample into one of at least four risk groups taking into account the gene expression levels of the genes for HMGA2 and PPAR-gamma in the sample and the body fat percentage, in particular the BMI of the donor, wherein the classification is done into one of the groups selected from the group consisting of a) elevated relative gene expression level for HMGA2, reduced relative gene expression level for PPAR-gamma and elevated body fat percentage, in particular average BMI ≥ 25, b) reduced relative gene expression level for HMGA2, reduced relative gene expression level for PPAR-gamma and elevated body fat percentage, in particular average BMI ≥ 25, c) reduced relative gene expression level for HMGA2, reduced gene expression level for PPAR-gamma and non-elevated body fat percentage, in particular average BMI < 25, d) reduced relative gene expression level for HMGA2, elevated relative gene expression level for PPAR-gamma and non-elevated body fat percentage, in particular average BMI < 25, a) elevated relative gene expression level for HMGA2, reduced relative gene expression level for PPAR-gamma and elevated body fat percentage, in particular average BMI ≥ 25, b) reduced relative gene expression level for HMGA2, reduced relative gene expression level for PPAR-gamma and elevated body fat percentage, in particular average BMI ≥ 25, c) reduced relative gene expression level for HMGA2, reduced gene expression level for PPAR-gamma and non-elevated body fat percentage, in particular average BMI < 25, d) reduced relative gene expression level for HMGA2, elevated relative gene expression level for PPAR-gamma and non-elevated body fat percentage, in particular average BMI < 25,