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

Study answer

What this study found

Both whey protein loads altered gastric emptying, gut hormone responses, and short-term appetite, and both suppressed buffet energy intake versus control. Gastric emptying was slower with whey protein, with T50 of 26 6 3 min for 30 g and 65 6 9 min for 70 g versus 12 6 0.5 min for control (P < 0.001). Buffet intake was lower after both loads, at 1027 6 81 kcal with 30 g and 998 6 71 kcal with 70 g versus 1174 6 91 kcal with control (P < 0.01), while total energy intake was not significantly different (P = 0.07). Higher protein load produced more sustained hormone responses, including higher…

Study & population

Randomized, double-blind, crossover study in healthy, lean men at the Royal Adelaide Hospital, Australia.

Intervention

Two acute oral whey protein isolate drinks were tested on separate study days: a low-load drink containing 30 g and a high-load drink containing 70 g, each in 450 mL total volume.

Key limitation

Small sample size and a narrow population of healthy, lean men limit generalizability.

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Original abstract