This prospective randomized study enrolled 66 elderly malnourished or at-risk patients in an inpatient rehabilitation unit. All were given a controlled diet for 6 wk. In a spread diet (SD) group (n = 36), dietary protein was spread over the four daily meals. In a pulse diet (PD) group (n聽=聽30), 72% of dietary protein (averaging 1.31 g/kg body weight daily) was consumed in one meal at noon. The patients were evaluated on day 1 and at 6 wk for plasma postprandial (five times from 0 to +180 min) AA concentrations (expressed as area under the curve above baseline).
Protein pulse feeding was more efficient than protein spread feeding at increasing plasma postprandial AA concentrations, notably of essential AAs. This increased postprandial AA bioavailability was maintained after 6 wk.
This study demonstrates that increased postprandial AA bioavailability induced by protein pulse feeding persists after 6 wk (i.e., that there is no metabolic adaptation blunting AA bioavailability).