Effects of complete whey-protein breakfasts versus whey without GMP-breakfasts on energy intake and satiety.
OBJECTIVE
To compare the effects of whey versus whey without glycomacropeptide (GMP) in a high and a normal amount of protein in a breakfast custard on satiety and energy intake (EI), taking concentrations of amino acids (AA), glucose, insulin, glucagon-like peptide 1 (GLP-1) and ghrelin into account.


METHODS
Twenty-five healthy subjects (mean+/-S.E.M., BMI: 23.9+/-0.3 kg/m(2); age: 22+/-1 years) received a breakfast containing whey or whey without GMP as protein type with 10/55/35 or 25/55/20 En% protein/carbohydrate/fat in a randomized, single-blind design. Appetite profile (Visual Analogue Scale, VAS), glucose, insulin, GLP-1, ghrelin and AA concentrations were measured, and the adequate moment for ad libitum lunch was determined based on differences in ghrelin concentration. In a second set of experiments subjects received the same breakfasts; ad libitum lunch was offered at the pre-determined moment.


RESULTS
After a breakfast with 25 En% protein increases in insulin and GLP-1 and decreases in ghrelin concentrations were larger; increases in satiety ratings were lower than after 10 En% (p<0.05); there was a treatment x time interaction effect on glucose and insulin concentrations (p<0.001). After a breakfast with whey without GMP insulin concentrations were increased more than after whey (p<0.05). EI at lunch was lower after whey than after whey without GMP (2877+/-165 kJ versus 3208+/-178 kJ, p<0.05), coinciding with more increased concentrations of serine, threonine, alanine, alpha-aminobutyric acid and isoleucine (p<0.05).


CONCLUSIONS
GMP as a whey-fraction reduced energy intake coinciding with increased concentrations of certain amino acids, irrespective of the concentration of whey-protein. Although between different concentrations of whey-protein differences in hormone responses were observed, these were unrelated to satiety ratings or energy intake.
Veldhorst
Margriet A B
MA
Dept. of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands. m.veldhorst@hb.unimaas.nl
Nieuwenhuizen
Arie G
AG
Hochstenbach-Waelen
Ananda
A
Westerterp
Klaas R
KR
Engelen
Marielle P K J
MP
Brummer
Robert-Jan M
RJ
Deutz
Nicolaas E P
NE
Westerterp-Plantenga
Margriet S
MS
D000596:Amino Acids / Q000032:analysis; D001066:Appetite; D001786:Blood Glucose / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis; D002149:Energy Intake; D054439:Ghrelin / Q000032:analysis; D006801:Humans; D007328:Insulin / Q000097:blood; D008894:Milk Proteins / Q000032:analysis; D010455:Peptides / Q000032:analysis; D011897:Random Allocation; D012528:Satiety Response; D016037:Single-Blind Method; D000067816:Whey Proteins
D000596:Amino Acids; D001786:Blood Glucose; D004044:Dietary Proteins; D054439:Ghrelin; D007328:Insulin; D008894:Milk Proteins; D010455:Peptides; D000067816:Whey Proteins