EFFECT OF VARIABLE PROTEIN-INTAKE ON WHOLE-BODY PROTEIN-TURNOVER IN YOUNG MEN AND WOMEN

The effect of the amount of protein intake (12% and 21% of total energ y intake, diet A and diet B, respectively) on nitrogen balance and who le-body protein turnover (PT) was measured in 19 young men and 10 youn g women (aged 30 +/- 5 and 27 +/- 4 y, respectively). In young adults, mean nitrogen balance was approximately zero during diet A whereas it was positive during diet B. In young adults, PT was significantly hig her during diet B in comparison with diet A. This was also seen in eld erly subjects, as described before. From a comparison of the current d ata with the data previously obtained in elderly subjects it can be co ncluded that during diet A young adults had PT rates higher than those of elderly subjects. During diet B, PT of young men was comparable wi th the PT of elderly men whereas young women still had higher PT rates than elderly women (even when corrections were made for differences i n body composition).