Nutrition problems occurred during the transition from adolescence to adulthood, including a decrease in hemoglobin levels and malnutrition Female students in islamic boarding schools whofasted experienced a reduction in meal frequency from three times a day to twice a day, without snacks in between. Insufficient nutrient intake can affect nutrient balance and lower hemoglobin levels. In addition to decreased hemoglobin levels (anemia), nutritional status can also lead to health problems. This study aims to assess the differences in hemoglobin levels and nutritional status between islamic boarding school students observing monday-thursday fasting and those not observing it. The research employed a cross-sectional method with purposive sampling, involving 88 respondents, catagorized into two groups: individuals fasting on mondays-thursdays and those not fasting. The sample size was determined using the unpaired categorical comparative formula. Primary data on hemoglobin levels were measured using the easy touch gchb device, primary data on nutritional status data were obtained through height and weight measurements, and dietary habits were using the sq-ffq questionnaire over the last three months, conducted over two weeks in february 2025. Data analysis was conducted using the mann-whitney test. The research results showed a significant difference in hemoglobin levels between the group that observed mondays-thursdays for the past two months (6 times) and the non-fasting group, with the mahasantri majority having normal hemoglobin levels p= 0.002 (p< 0.05). However, there was no significant difference in nutritional status between students fasted and those not fast, with p= 0.161 (p > 0.05). In conclusion, there is a significant difference in hemoglobin levels between students who fast on mondays-thursdays for the past two months (6 times) and those not fast, whereas no significant difference was found in the nutritional status between the two groups.