The notion of "oxidative stress" was introduced by Sies, in 1985, and designates all the oxidative damages caused by the free radicals of oxygen. Oxidative stress represents the imbalance of pro-oxidant and antioxidant ratio, in favor of the former, following the excessive action of the "aggressor" and/or the decrease of the "defender's" capacity to oppose.
Material and method: In the current study we had 82 overweight patients (42 patients less than 65 years old and 40 patients over 65). The criteria for inclusion was weight over 80 Kg and BMI > 30. Patients were monitored and assessed every three, six, nine months and each year.
Results: Obesity together with dyslipidemia, smoking, diabetes and high blood pressure intensifies oxidative stress. The improvement of these factors determines the growth of antioxidant enzyme level (SOD and GPX) and the reduction of malondialdehyde level.