Figure 4. Expired ¹³CO₂ enrichments (A) and plasma ¹³C-phenylalanine enrichments (B) in mol per cent excess (MPE) as a function of time in elderly volunteers during the basal postabsorptive period and during ingestion of a control diet or a leucine-supplemented diet given as a repeated bolus between 0 and 300 min.

Values are means ± s.e.m. †Significantly different from basal period at P < 0.05.