Inclusion Criteria:  Inclusion criteria for cases (subjects with insulin resistance).  Male and female. Adults between 18 and 50 years of age. Body Mass Index (BMI) ≥ 18.5 and ≤ 40 kg/m2. HOMA index ≥ 2.5 In the case of women, being in the follicular phase of the menstrual cycle.  Inclusion criteria for controls (subjects without insulin resistance).  Male and female Adults between 18 and 50 years of age. Body Mass Index (BMI) ≥ 18.5 and ≤ 40 kg/m2. HOMA index < 2.5 Blood glucose < 100 mg/dL In the case of women, being in the follicular phase of the menstrual cycle.  Exclusion Criteria:  Patients with any type of diabetes. Patients with kidney disease diagnosed by any physician. Patients with creatinine > 1.3 mg/dL for men and > 1.1 mg/dL for women and/or Blood Urea Nitrogen (BUN) > 20 mg/dL. Patients with acquired diseases secondarily producing obesity and diabetes. Patients who have suffered a cardiovascular event. Weight loss > 3 kg in the last 3 months. Patients with any catabolic diseases. Pregnancy status. Positive smoking. Treatment with any medication (except contraceptives and proton pump inhibitors) Having suffered any infection in the last 20 days.