１，２歳児のたんぱく質，エネルギー摂取量および窒素出納成績

Since little is known about the nitrogen balance in children when the protein intake is about the level of the Japanese recommended dietary allowance (JRDA) and since few data have been reported about the amount of protein intake in daily life, a nitrogen balance study and a nutrition survey were carried out in children aged 1-2 years. The nitrogen balance of 22 children living in a nursing home was studied for 3 days. The amount of ingested food was obtained by weighing the food before and after cooking and after food was ingested. Nitrogen intake was calculated from the weight of ingested food and the nitrogen concentration of the food which was analyzed by the Kjeldahl method. Energy intake was calculated by using the Japanese food composition table. The nutrition survey of a village was done in summer (July) on 15 children and winter (December) on 9 children for 3 consecutive days. Nine of them were studied in both seasons. The amount of food ingested was obtained by the same manner as in the nitrogen balance study. Protein and energy intakes were calculated by using a Japanese food composition table. Height and weight were measured in both studies.<BR>Changes in height and weight of the children at the nursing home were similar to the Japanese average. With an intake of 460 mg nitrogen/kg/day (about the JRDA level for 1-2-year-old children), nitrogen retention was about 90 mg/kg/day. The energy intake of the children at the home was 78 kcal/kg/day, about 8 kcal lower than the JRDA value. The slope of the regression line between nitro-gen intake (x) and nitrogen balance (y) was O. 33, indicating that the protein utilization was about 33 %. Children in the village made normal height and weight gains during the 5 months. Their energy and protein intakes in summer and winter were 74 and 79 kcal/kg/day and 2.30 and 2.47 g/kg/day, respectively. Both the energy and the protein intakes were lower than those of the JRDA.<BR>The results indicate that JRDA of protein for children aged 1-2-year is sufficient to retain adequate body protein even with an energy intake lower than that of the JRDA.