A long-term metabolic study to assess the nutritional value of and immunological tolerance to two soy-protein concentrates in adult humans.

Seventeen healthy young adult men participated in a long-term metabolic study (11 wk) to evaluate the tolerance to and protein nutritional value of two commercially produced soy-protein concentrates. Danpro-S (nine subjects) and Danprotex-H 40 (eight subjects) (Aarhus Oliefabrik A/S, Aarhus, Denmark). Each test protein (0.8 g.kg-1.d-1) served as the sole source of dietary nitrogen. Subjects remained healthy, no problems of clinical or metabolic significance appeared, body weight remained constant, and body composition indices (lean body mass by H2(18)O dilution and creatinine excretion) and basal metabolic rate did not change. N balances fluctuated around body N equilibrium. Immunological studies confirmed the absence of any allergic responses in these subjects. It is concluded that these protein concentrates can be consumed as the sole source of dietary protein for protein nutritional maintenance and with excellent tolerance.