Vahideh Banazadeh - MSc in Nutritional Sciences, Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Mohsen Nematy - MD, PhD in Nutritional Sciences, Associate Professor of Nutritional Sciences, Department of Nutritional Sciences, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Ali Jangjoo - MD, Associate Professor, Surgical Oncology Research Center, Mashhad University of Medical Sciences,Mashhad, Iran

Background and Aim: The aim of this study was assessment six months post-surgical nutritional status and elucidation the relation between PAB (pro-oxidant antioxidant balance) values and Methods: Participants included 35 morbid obese patients (age 39.42 ± 11.76 years, 28 women) who were randomly recruited before the surgery. Pro-oxidant antioxidant level was evaluated by PAB assay. A three-day food record were collected before and six months after surgery. Data was analyzed by Nutritionist 4 software and compared with gastric bypass nutritional guidelines six months after surgery. Statistical analysis were carried out using SPSS version 16 software. P< 0.05 was considered as significant level.Results: In comparison with the baseline, there was a significant reduction in calorie, protein and micronutrients intake (p<0.001) except vitamin D (p=0.248). Daily calorie intake was in the range of and protein intake was too lower than recommended levels for patients after surgery. Partial correlation after controlling for sex variation and medication usage as confounding variables, showed significant correlation between six months post-surgical PAB values and dietary protein intake (r= -0.39, p=0.02), selenium (r= -0.36, p=0.03) and vitamin B12 (r= -0.46, p=0.007) status. In addition Multiple Hierarchal Regression Model demonstrated sex variation as female ( ^= - 27.832, p=0.041) and dietary vitamin B12 level ( = - 8.326, p=0.007) as PAB values predictors six months post treatment.Conclusion: Attention to the dietary deficiencies especially protein and micro-nutrients after gastric bypass surgery is high of importance due to their effect on oxidative stress status.

Gastric Bypass, Roux-en-Y; Status, Nutritional; Oxidative Stress; Micronutrients; Vitamin B12