Tehran University of Medical Sciences Journal of Biostatistics and Epidemiology 2383-4196 7 1 2021 05 18 70 85 Pegah Hemmatyar Department of Nutrition, Faculty of Medical Sciences and Technologies, Islamic Azad University, Science and Research Branch, Tehran, Iran. Sahar Hemmatyar Department of Nutrition, Faculty of Medical Sciences and Technologies, Islamic Azad University, Science and Research Branch, Tehran, Iran. Shahryar Eghtesadi Department of Nutrition, Faculty of Medical Sciences and Technologies, Islamic Azad University, Science and Research Branch, Tehran, Iran. Anahita Hoshyarrad National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mahmoud Mahmoudi Majdabadi Department of Health Services, Faculty of Medical Sciences and Technologies, Islamic Azad University, Science and Research Branch, Tehran, Iran. 2021 02 11 2021 04 03 Introduction: The incidence of multiple births in the world has increased significantly .There are few studies on the nutritional status of twins, to our knowledge, no study has been conducted in this field in Iran. These are among many reasons that make this study, which aims to identify major dietary patterns and Chronic Disease’s Effective Factors on the General Health Condition of Tehran’s Opposite Gender Adult Twins, valuable.  Materials and Methods: 128 people (64 pairs) of Opposite Gender Twins participated in this study. After completing the general information questionnaires, International Physical Activity, Semi-quantitative food frequency, and general health, anthropometric indices, and their blood pressure were measured. Dietary patterns were identified by factor analysis. The relationship between dietary patterns and factors affecting chronic diseases with general health was calculated using the logistic regression method.  Results: Two western and healthy dietary patterns were identified. There was a significant relationship between the Western dietary pattern and age, gender, and father's education. Twin participants who scored higher in a quarter of the Western dietary pattern were younger than those with lower scores, with men increasing and women decreasing. There was a significant difference in the distribution of healthy dietary  pattern with age, economic status, and systolic blood pressure. An increasing relationship was observed in age. The results showed that in first Twins, only Birth Weight, and Physical Activity, whereas, in second Twins besides Birth Weight, gender and Marital status were among the most significant factors in determining the general health of participants.  Conclusion: The present study shows that there are two major dietary patterns: healthy and western. The Western dietary pattern has the most variance and this indicates the nutritional transition and prevalence of the Western dietary pattern in Iran. The main finding of this study is the association of birth weight with general health in both twins. Birth weight is directly related to health. Those with low birth weight have more health problems in contrast to those with normal birth weight.   https://jbe.tums.ac.ir/index.php/jbe/article/view/444