Association of Dietary Pattern and Body Size with Early Menarche among Elementary School Girls in West of Iran

Background: The average age at menarche (AAM) has declined around the world, which is widely attributed to improvements in nutrition. This study was conducted to investigate the association between dietary patterns and early menarche ( Materials and Methods: This case-control study was carried out on 400 elementary school girls (200 early menarche and 200 premenarche) who were aged 12 years old and over, in Kermanshah, Iran, 2015. The participants were selected by cluster sampling from three areas of Kermanshah city. Body mass index (BMI) was calculated, and information on dietary intake was investigated by using a semi-quantitative food frequency questionnaire, which consists of 160 items and were filled by students’ parents. Logistic regression was performed to find a relationship between dietary patterns and risk of early menarche. Results: The means age for the case and control groups (n=200, n=200) were 12.06±0.1 5 years and 12.0 6±0. 10 years, respectively. Four major dietary patterns of meat, western, vegetarian, and traditional were identified. After adjusting for the confounding factors, vegetarian (OR: 0.01; 95%CI: 0.003-0.02; P<0.001), and traditional (OR: 0.13; 95%CI: 0.06-0.26; P<0.001), dietary patterns were found to be negatively associated with early menarche whereas the highest tertile of meat dietary pattern (OR:1.21; 95%CI: 0.64-2.29; P<0.009), and BMI (OR: 3.36; 95%CI: 1.72-6.54) were positively associated with early menarche. Western diet showed no relationship with early age at menarche (P>0.05). Conclusion: Based on the results, dietary patterns and body size were found to be related to early menarche among elementary school girls.