The Protein Requirements of College Women on High Cereal Diets with Observations on the Adequacy of Short Balance Periods ,

Abstract

Ten college girls, 19 to 30 years of age, cooperated in a study of the protein needs of adults. During an experimental period of 105 days, divided into 4 periods, the following were determined: (1) nitrogen balances on a low protein diet; (2) individual protein needs for nitrogen equilibrium and estimated “adult growth” needs when subjects received a diet in which 70% of the protein was of cereal origin; and (3) adequacy over a 10-week period of these estimated protein needs for maintenance of nitrogen equilibrium and physical well-being (as indicated by three psychomotor tests, 5 tests of preceptual and intellective function, and one test of physical endurance). The results were as follows: It may be concluded from these studies: (1) that for diets of the type used, containing predominant proportions of cereal proteins, the average daily requirement for adult maintenance and growth is 31.7 ± 1.6 gm per person or 25 gm per 1000 cal. of basal heat; and (2) that the protein requirements computed from experimental periods of such length that the urinary nitrogen attains a relatively constant level are valid for periods of at least 70 days.