Tehran University of Medical Sciences Journal of Nutritional Sciences and Dietetics 1 3 2015 12 07 134 140 EN Mehri Mirahmadian Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran Motahareh Hasani Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran Ehsaneh Taheri Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran Abbasali Keshtkar Osteoporosis Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran Saeed Hosseini Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, AND Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran AbdolReza Pazooki Minimally Invasive Surgery Research & Training Center of Excellence, Iran University of Medical Sciences, Tehran, Iran 2015 12 07 2015 12 07 Background: Obesity is recognized as a major public-health problem, which has reached epidemic proportions, in both developed and developing countries. The purpose  of   this   survey  is   to   study  effects  of   gastric  bypass  surgery  at micronutrients and macronutrients intake on patients with morbid obesity. Methods:   This quasi-experimental study was conducted on 21    patients. Anthropometry information (weight, height, age, and gender) and three 24-hour recall questionnaires were completed for each participant: Before surgery and 3 months after surgery. Results: The total intake of macronutrients including carbohydrate, protein and fat decreased between baseline at 3 months post-surgery that was statistically significant for all of the macro-nutrients (p < 0.001). There was a reduction of energy intake from carbohydrate (54.81% ± 20.03% to 44.34% ± 14.59%, p = 0.059) and the energy intake from protein (18.57% ± 5.73% to 26.24% ± 9.83%, p = 0.001) and fat (31.06%± 8.64% to 35.18% ± 25.41%, p = 0.460) along the prospective follow-up period compared to previous values. The mean intake of all micronutrients had decreased during follow-up that was statistically significant for B group vitamins (B1, B2, B3, and B6), float, iron, zinc and copper (p < 0.017 for vitamin B2, p < 0.001 for others). Conclusion: Our data demonstrate that low dietary intake of energy, micro- and macro-nutrients  absolute   values  and   relative   to   the   recommended   dietary allowances and estimated average requirements, are highly prevalent after Roux- en-Y  gastric  bypass  (RYGB)  surgery.  Therefore  dietary  counseling,  clinical assessments, and the recommendation of supplements if needed in pre- and post- operatively, might be considered for health promotion after RYGB surgeries. https://jnsd.tums.ac.ir/index.php/jnsd/article/view/31 https://jnsd.tums.ac.ir/index.php/jnsd/article/download/31/20