DIETARY-INTAKE AND NITROGEN-BALANCE IN INSTITUTIONALIZED JAPANESE OLD-PEOPLE

The habitual dietary intake of elderly people was investigated by long term dietary survey (15 mos, two days a week) in 14 institutionalized and apparently healthy Japanese, aged 70-86 years, under their normal living conditions, using the food-weighing method. Nutrient intakes were calculated using the food table. Mean intakes for males and females were, respectively: energy (1802 and 1509 kcal/d), protein (55 and 50 g/d), VA (1538 and 1736 IU/d), VB1 (3.5 and 2.4 mg/d), VB2 (0.7 and 0.9 mg/d), niacin (19.5 and 14.3 mg/d), VC (61 and 108 mg/d), VD (44 and 33 IU/d), Ca (379 and 542 mg/d) and Fe (10.8 and 9.8 mg/d). Nitrogen balance study was also conducted under the usual level of protein intake (1 g/kg/d) during the period of usual diet (35% as animal protein) and vegetable protein diet (soybean foods substituted for animal foods of the usual diet). Nitrogen balances of usual and vegetable protein diet periods were not significantly different, being 46 +/- 20 mg/kg/d and 28 +/- 25 mg/kg/d, respectively, for both sexes, suggesting that the substitution of soybean foods for animal foods in the usual diet did not affect the protein quality of the diet for elderly people. Also, this level of protein intake (1 g/kg/d) seems to be adequate for both sexes in their advanced years.