A Study on Nitrogen Intake and Excretion in Young Korean Adult Women on Normal Diet

정상식이를 섭취하는 여대생들의 질소 섭취 및 배설에 관한 연구

A study was conducted to measure nitrogen intake and excretion in young korean women on their normal diet and leading normal activity level. Dietary survey by food record, fecal and urinary samples were collected for 3 days in 19 healthy female college students in Korea. On one of the 3 days, duplicate of one-day diet was collected from each subjects. Mean daily intakes of energy and protein were calculated from food recorded. Duplicate diet samples and pooled fecal samples were analyzed for N content. Pooled urine samples were analyzed for total N, urea N, and creatinine content. Apparent N absorption, apparent N balance and urea N/creatinine N were calculated to evaluate protein nutritional status. The results obtained are summarized as following ; 1) Accordingly to food record, mean daily intakes of energy, protein, carbohydrate and far were 1535.2 $\pm$53.78Kcal, 55.95$\pm$2.97g(total nitrogen 8.95$\pm$0.45g), 254.13$\pm$10.31g and 39.24$\pm$2.76 g, providing 14.6%, 66.2%, 19.2% of total energy respectively. 2) Nitrogen intake by chemical analysis was 7.16$\pm$0.31g/day (protein 44.75$\pm$1.94kg/day) providing 82.39$\pm$4.58% of nitrogen intake by food record. The difference of total nitrogen intake between food record and chemical analysis in diets was significant(p<0.05). 3) Mean daily fecal nitrogen excretion was 1.38$\pm$0.10g and then mean apparent digesbility of protein was 80.53$\pm$5.21%. 4) Mean daily urinary nitrogen excretion, urea N excretion and creatinine excretion were 6.03$\pm$0.30g, 4.52$\pm$0.22g, and 0.88$\pm$0.04g respectively. Urinary urea nitrogen was 75.2$\pm$1.38% of total urinary nitrogen excretion and urinary nitrogen was 85.4$\pm$3.56% of total nitrogen intake by chemical analysis. 5) Mean urea N/creatinine N ration was 14.01$\pm$0.77. 6) Mean nitrogen balance was -0.244$\pm$0.33g/day. From the above results, it is concluded that the subjects in this study seem to be in marginal protein nutritional status and therefore should increase dietary protein intake.