Gangguan siklus menstruasi merupakan indikator klinis awal dalam mendeteksi Polycystic Ovary Syndrome (PCOS) pada remaja yang telah mengalami menstruasi sejak dua tahun yang lalu. Angka gangguan siklus menstruasi pada remaja di DKI Jakarta (17,2%) melebihi angka nasional (11,7%). Berbagai faktor gaya hidup diduga berkontribusi terhadap gangguan siklus menstruasi, di antaranya status gizi, asupan zat gizi makro, kebiasaan konsumsi makanan cepat saji modern, aktivitas fisik, dan tingkat stres. Penelitian ini bertujuan untuk mengetahui faktor dominan gangguan siklus menstruasi pada siswa SMAN 34 Jakarta tahun 2026. Penelitian menggunakan pendekatan kuantitatif dengan desain penelitian cross-sectional. Penelitian ini melibatkan 151 siswa perempuan kelas X dan XI yang telah memenuhi kriteria penelitian. Pengumpulan data dilakukan pada bulan April—Juni 2026 dengan instrumen penelitian berupa kuesioner menstruasi, IMT/U (Indeks Massa Tubuh/Usia), SQ-FFQ (Semi Quantitative-Food Frequency Questionnaire), FFQ (Food Frequency Questionnaire),  IPAQ-SF (International Physical Activity Questionnaire-Short Form), PSS-10 (Perceived Stress Scale). Hasil penelitian menunjukkan bahwa 28,5% responden mengalami gangguan siklus menstruasi. Selain itu, ditemukan adanya hubungan signifikan antara status gizi  (p-value=0,002; OR=3,373) dan aktivitas fisik (p-value=0,019; OR=0,423) terhadap gangguan siklus menstruasi. Melalui uji regresi logistik, status gizi lebih dan obesitas merupakan faktor dominan gangguan siklus menstruasi (OR=3,8). Selain itu, ditemukan indikasi fenomena RED-S pada siswa dengan aktivitas fisik sedang-berat sebagai temuan tabulasi silang. Penelitian menyarankan untuk menjaga status gizi tetap normal melalui pembatasan konsumsi makanan cepat saji modern dan peningkatan aktivitas fisik serta memastikan kecukupan asupan energi bagi siswa yang aktif secara fisik untuk mencegah kondisi LEA.

Menstrual cycle disorders are an early clinical indicator for detecting Polycystic Ovary Syndrome (PCOS) in adolescents who have been menstruating for at least two years. The prevalence of menstrual cycle disorders among adolescents in DKI Jakarta (17,2%) exceeds the national figure (11,7%). Various lifestyle factors are suspected to contribute to menstrual cycle disorders, including nutritional status, macronutrient intake, modern fast food consumption habits, physical activity, and stress levels. This study aimed to identify the dominant factors of menstrual cycle disorders among students of SMAN 34 Jakarta in 2026. The study used a quantitative approach with a cross-sectional design, involving 151 female students from grades X and XI who met the inclusion criteria. Data collection was conducted from April to June 2026 using the following instruments: menstrual questionnaire, BMI-for-age (IMT/U), SQ-FFQ (Semi Quantitative-Food Frequency Questionnaire), FFQ (Food Frequency Questionnaire), IPAQ-SF (International Physical Activity Questionnaire-Short Form), and PSS-10 (Perceived Stress Scale). The results showed that 28.5% of respondents experienced menstrual cycle disorders. Significant associations were found between nutritional status (p-value=0.002; OR=3.373) and physical activity (p-value=0.019; OR=0.423) with menstrual cycle disorders. Through logistic regression analysis, overweight and obese nutritional status was identified as the dominant factor of menstrual cycle disorders (OR=3.8). Additionally, indications of RED-S were found among students with moderate-to-vigorous physical activity as an exploratory finding. The study recommends maintaining normal nutritional status through limiting modern fast food consumption, increasing physical activity, and ensuring adequate energy intake for physically active students to prevent LEA.