Effect of premeal consumption of whey protein and its hydrolysate on food intake and postmeal glycemia and insulin responses in young adults

Am J Clin Nutr. 2010 Apr;91(4):966-75. doi: 10.3945/ajcn.2009.28406. Epub 2010 Feb 17.


Background: Dairy protein ingestion before a meal reduces food intake and, when consumed with carbohydrate, reduces blood glucose.

Objective: The objective was to describe the effect of whey protein (WP) or its hydrolysate (WPH) when consumed before a meal on food intake, pre- and postmeal satiety, and concentrations of blood glucose and insulin in healthy young adults.

Design: Two randomized crossover studies were conducted. WP (10-40 g) in 300 mL water was provided in experiment 1, and WP (5-40 g) and WPH (10 g) in 300 mL water were provided in experiment 2. At 30 min after consumption, the subjects were fed an ad libitum pizza meal (experiment 1) or a preset pizza meal (12 kcal/kg, experiment 2). Satiety, blood glucose, and insulin were measured at baseline and at intervals both before and after the meals.

Results: In experiment 1, 20-40 g WP suppressed food intake (P < 0.0001) and 10-40 g WP reduced postmeal blood glucose concentrations and the area under the curve (AUC) (P < 0.05). In experiment 2, 10-40 g WP, but not WPH, reduced postmeal blood glucose AUC and insulin AUC in a dose-dependent manner (P < 0.05). The ratio of cumulative blood glucose to insulin AUCs (0-170 min) was reduced by > or =10 g WP but not by 10 g WPH.

Conclusions: WP consumed before a meal reduces food intake, postmeal blood glucose and insulin, and the ratio of cumulative blood glucose to insulin AUCs in a dose-dependent manner. Intact WP, but not WPH, contributes to blood glucose control by both insulin-dependent and insulin-independent mechanisms. This trial was registered at clinicaltrials.gov as NCT00988377 and NCT00988182.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Area Under Curve
  • Blood Glucose / metabolism*
  • Cross-Over Studies
  • Dietary Proteins / administration & dosage*
  • Dose-Response Relationship, Drug
  • Energy Intake / drug effects*
  • Female
  • Humans
  • Hydrolysis
  • Insulin / blood*
  • Male
  • Milk Proteins / pharmacology*
  • Postprandial Period
  • Satiety Response / drug effects*
  • Whey Proteins
  • Young Adult


  • Blood Glucose
  • Dietary Proteins
  • Insulin
  • Milk Proteins
  • Whey Proteins

Associated data

  • ClinicalTrials.gov/NCT00988182
  • ClinicalTrials.gov/NCT00988377