Menstrual cycle regularity is a key indicator of reproductive and overall health in women of reproductive age. Nutritional status, encompassing dietary intake, body composition, and micronutrient levels, has been recognized as a significant factor influencing menstrual patterns. This study aimed to investigate the relationship between nutritional status and menstrual cycle regularity among women aged 18–35 years. A cross-sectional design was employed, involving 250 participants recruited from university campuses and community health centers. Data on menstrual history, cycle length, and irregularities were collected using a structured questionnaire, while anthropometric measurements, including body mass index (BMI), waist-to-hip ratio, and body fat percentage, were assessed to determine nutritional status. Dietary intake was evaluated using a 24-hour dietary recall and a food frequency questionnaire.

Statistical analyses included chi-square tests and logistic regression to examine associations between nutritional indicators and menstrual regularity. The findings revealed that both undernutrition (BMI <18.5 kg/m²) and overweight/obesity (BMI ≥25 kg/m²) were significantly associated with menstrual irregularities (p < 0.05). Women with inadequate caloric intake, low iron levels, and deficiencies in vitamin D and B-complex vitamins exhibited higher rates of oligomenorrhea and amenorrhea. Conversely, participants maintaining balanced macronutrient distribution and normal BMI demonstrated more consistent menstrual cycles.