1. Partial recovery Lost sample 1,000 fmols 0.1 fmols 1.0 fmols Neg. control Supplemental Fig. 1. Quality control for extraction procedures using spiked-in miRNAs from C. elegans. Only qRT-PCR pictures assessed for cell-miR-39 are shown. Total recovery Neg. control Samples

2. Supplemental Fig. 2. Distribution of miRNA expression based on the quality after removing all miRNAs with Ct values ≥35 and cluster analysis heatmap plot according to the quality of all determinations. A slightly tendency of the majority of morbid obese (BMI>40 kg/m 2 ) men expressing higher number of miRNAs with a Ct value below 35 Ct was reported. NW (green): Nomalweight, OW (yellow): Overweight, Ob (orange): Obesity, and MOb (red): Morbid obesity. * (violet) indicates subjects with type 2 diabetes.

3. Supplemental Fig. 3. Distribution of miRNA expression based on the quality after removing all miRNAs with Ct values ≥35, and cluster analysis heatmap plot according to the quality of all determinations. The tendency of the morbid obese (BMI>40 kg/m 2 ) subjects expressing higher number of miRNAs with a Ct value below 35 Ct before surgery weight-loss (red) was also shown.

4. Supplemental Fig. 4. Gene expression stability measure (M, which is the mean pair-wise variation for a gene from all other tested control genes) calculated using the applet GeNorm according to the number of reference miRNAs.

5. r=0.44 p<0.0001 r=0.37 p<0.0001 r=0.42 p<0.0001 r=-0.41 p<0.0001 r=-0.42 p<0.0001 r=-0.44 p<0.0001 r=-0.57 p<0.0001 r=-0.32 P=0.004 Supplemental Fig. 5. Scatter plot representing for the whole cohort (n=80) the correlation between the normalized expression values (even Log 2 -normalized relative values, or the anti-Log 2 -transformed DeltaCps values of the means) for (A) miR-142- 3p, (B) miR-140-5p, (C) miR-222, (D) miR-221, (E) miR-15a, (F) miR-520c-3p, (G) miR-423-5p, and (H) miR-130b. Values for non-obese men (the reference group) are represented as empty circles (○); obese (30≤ BMI< 40 kg/m 2 ) subjects are represented as empty diamonds (◊); and morbid obese (BMI≥ 40 kg/m 2 ) patients as filled diamonds (  ).

6. Supplemental Fig. 6. Hierarchical clustering (Ward’s criterion) deduced from the qRT-PCR data using independent hydrolysis probes and miRNAs profiles depicting genomic relatedness among the subjects of the whole cohort. NW (green): Normoweight, OW (yellow): Overweight, Ob (orange): Obesity, and MOb (red): Morbid obesity. * (violet) indicates subjects with type 2 diabetes.