Latar belakang: Menarke merupakan kondisi ketika seorang remaja putri mengalami menstruasi pertama kali. Di Indonesia, usia menarke diketahui mengalami tren penurunan. Menarke dini dapat meningkatkan berbagai risiko terjadinya masalah-masalah kesehatan, di antaranya masalah reproduktif dan psikologis. Perubahan gaya hidup hingga asupan nutrisi diyakini menjadi faktor-faktor yang dapat mempengaruhi usia menarke baik secara langsung maupun tidak langsung. Untuk itu, penelitian ini bertujuan untuk menganalisis hubungan antara indeks massa tubuh, aktivitas fisik, dan konsumsi ultra-processed food dengan usia menarke.Metode: Penelitian ini dilakukan dengan desain cross-sectional. Pengukuran berat badan dan tinggi badan, pengisian kuesioner, dan wawancara 24 hour recall dilakukan dalam pengumpulan data. Analisis data dalam penelitian ini menggunakan uji Kruskal-Wallis dan Mann-Whitney. Uji post-hoc Mann-Whitney juga dilakukan untuk variabel yang signifikan.Hasil: Didapatkan 91 sampel yang sudah menstruasi dari 3 sekolah dasar dan 1 sekolah menengah pertama di Jakarta Barat. Berdasarkan analisis data, didapatkan terdapat hubungan antara indeks massa tubuh dan usia menarke (p < 0,011). Namun, tidak didapatkan adanya hubungan yang signifikan antara aktivitas fisik dan konsumsi ultra-ptocessed food terhadap usia menarke (p > 0,05).Kesimpulan: Terdapat hubungan antara indeks massa tubuh (IMT) dan usia menarke, sedangkan aktivitas fisik dan konsumsi ultra-processed food tidak berhubungan dengan usia menarke.

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Introduction: Menarche is a condition when a young woman experiences menstruation for the first time. In Indonesia, the age of menarche is known to experience a downward trend. Early menarche can increase the risk of various health problems, including reproductive and psychological problems. Changes in lifestyle and nutritional intake are believed to be factors that can affect the age of menarche either directly or indirectly. Therefore, this study aimed to analyze the relationship between body mass index, physical activity, and consumption of ultra-processed food and age at menarche.

Methods: This study was conducted with cross-sectional design study. Measurement of weight and height, filling out questionnaires, and interview using 24 hours recall were carried out in data collection. Data analysis in this study used the Kruskal-Wallis and Mann-Whitney tests. Post-hoc test using Mann-Whitney test was also performed for significant variable.

Results: There were 91 samples who had menstruated from 3 elementary schools and 1 junior high school in West Jakarta. Based on data analysis, it was found that there was a relationship between body mass index and age at menarche (p < 0.011). However, there was no relationship found between physical activity and consumption of ultra-processed food on the age of menarche (p > 0.05).

Conclusion: There is a relationship between body mass index (BMI) and age at menarche, while physical activity and consumption of ultra-processed food are not associated with age at menarche.