Acute load-dependent effects of oral whey protein on gastric emptying, gut hormone release, glycemia, appetite, and energy intake in healthy XXXX .

@entity1 @entity1522 @entity2690 @entity8586 @entity413
BACKGROUND: In healthy individuals, intraduodenal whey protein load-dependently modulates gastrointestinal motor and hormonal functions and suppresses energy intake. The effect of oral whey, particularly the impact of load, has not been evaluated. OBJECTIVE: The purpose of this study was to quantify gastric emptying of 30 and 70 g of oral whey protein loads and their relation to gastrointestinal hormone, glycemic, and appetitive responses. DESIGN: On 3 separate occasions in a randomized, double-blind order, 18 lean @entity1 [mean    SEM age: 24.8    1.4 y; body mass index (in kg/m(2)): 21.6    0.5] received iso-osmolar, equally palatable drinks (   450 mL) containing 30 g pure whey protein isolate (L), 70 g pure whey protein isolate (H), or saline (control). Gastric emptying (with the use of 3-dimensional ultrasound), plasma @entity8586 , glucagon-like peptide 1, @entity413 -dependent insulinotropic peptide, @entity2690 , glucagon, total @entity1522 , and blood @entity413 were measured for 180 min after consumption of the drinks, and energy intake at a buffet-style lunch was quantified. RESULTS: Gastric emptying of the L and H drinks was comparable when expressed in kilocalories per minute (L: 2.6    0.2 kcal/min; H: 2.9    0.3 kcal/min) and related between individuals (r = 0.54, P < 0.01). Gastrointestinal hormone, @entity2690 , and glucagon responses to the L and H drinks were comparable until    45-60 min after ingestion, after which time the responses became more differentiated. Blood @entity413 was modestly reduced after the H drink between t = 45 and 150 min when compared with the L drink (all P < 0.05). Energy intake was suppressed by both L and H drinks compared with control (P < 0.05) (control: 1174    91 kcal; L: 1027    81 kcal; and H: 997    71 kcal). CONCLUSION: These findings indicate that, in healthy lean @entity1 , the rate of gastric emptying of whey protein is independent of load and determines the initial gastrointestinal hormone response. This study was registered at www.anzctr.org.au as 12611000706976.
