Effect of whey protein and a free amino acid mixture simulating whey protein on measures of satiety in normal-weight women.
Dietary protein is considered more satiating than carbohydrate, and whey protein is more satiating than other protein sources. The purported satiating effect of whey protein may be due to direct effects of the unique mixture of proteins in whey, due to the effects of peptides released upon digestion and/or its amino acid composition. The objective of the present study was to compare the satiating effects of intact whey protein isolate (WPI) or a free amino acid mixture (AAM) simulating the amino acid composition of the WPI. A single-blind completely randomised block design included twenty, healthy, adult women (age 24·2 (sem 0·8) years) of normal weight (BMI 22·7 (sem 0·4) kg/m2). Following consumption of isoenergetic (approximately 1800 kJ) preload meals enriched (52 g amino acid equivalent) with WPI or AAM, consumption of an ad libitum test meal 120 min later and subjective feelings of appetite using visual analogue scales (VAS) were determined. There were no significant differences (P=0·24) in the ad libitum test meal intakes between the WPI (268·5 (sem 27·3) g) and the AAM (238·4 (sem 22·7) g) preload meals. Subjective VAS ratings of appetite did not differ significantly between the WPI and the AAM preload meals (P>0·05). Intact whey protein and a free AAM simulating the whey protein showed similar effects on satiety. This suggests that the satiating effect of whey protein may be related to its specific amino acid composition.
1Riddet Institute,Massey University,Private Bag 11-222,Palmerston North 4442,New Zealand.
Sylvia M S
SM
Chungchunlam
1Riddet Institute,Massey University,Private Bag 11-222,Palmerston North 4442,New Zealand.
Sharon J
SJ
Henare
2AgResearch Grasslands Research Centre,Tennent Drive,Private Bag 11-008,Palmerston North 4442,New Zealand.
Siva
S
Ganesh
1Riddet Institute,Massey University,Private Bag 11-222,Palmerston North 4442,New Zealand.
Paul J
PJ
Moughan
D000328:Adult; D000596:Amino Acids / Q000008:administration & dosage* / Q000009:adverse effects; D000818:Animals; D001067:Appetite Depressants / Q000008:administration & dosage* / Q000009:adverse effects; D062408:Breakfast; D003212:Condiments / Q000009:adverse effects; D002149:Energy Intake; D005260:Female; D005518:Food Preferences; D005526:Food, Formulated / Q000009:adverse effects; D019648:Foods, Specialized / Q000009:adverse effects; D006801:Humans; D062409:Lunch; D009520:New Zealand; D019518:Postprandial Period; D012528:Satiety Response; D057566:Self Report; D016037:Single-Blind Method; D000067816:Whey Proteins / Q000008:administration & dosage* / Q000009:adverse effects; D055815:Young Adult
D000596:Amino Acids; D001067:Appetite Depressants; D000067816:Whey Proteins
 AAM amino acid mixture;  BCAA branched-chain amino acids;  ME metabolisable energy;  VAS visual analogue scale;  WPI whey protein isolate;  net iAUC net incremental AUC; Amino acids; Food intake; Human nutrition; Satiety; Whey protein