Study analysis · European Journal of Clinical Nutrition · 2015
Whey protein triggers a hormone storm that keeps you full for hours—and it’s not just about lowering ghrelin.
In normal-weight women, a 45g dose of whey protein boosts fullness hormones like CCK, GLP-1, PYY, and pancreatic polypeptide more than an equal-calorie carbohydrate drink, while ghrelin drops equally for both.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
In simple terms
This study is like a test where scientists gave women two different drinks—one with whey protein and one with sugar—and checked their blood for chemicals that tell the brain 'I'm full.' They found that the protein drink made more of those 'full' chemicals. But this study only looks at what's in the blood, not if the women actually ate less later. So we can say the protein drink changed these chemicals, but we can't say for sure it makes people eat less.
What’s the bottom line?
Scientists gave 18 women a drink with whey protein or sugar (maltodextrin) and measured hormones that control hunger. They found that whey protein increased several 'fullness hormones' (CCK, GLP-1, PYY, PP) in the blood, while sugar did not. This might explain why protein helps you feel full.
How strong is this study?
The study was done carefully: it was a fair test where each woman tried both drinks, and they didn't know which one they were getting. But only 18 women took part, which is a small group, and the test only lasted two hours. A bigger study with more people and a longer time would make the results stronger.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
70 / 100
- Randomization+20/20
- Blinding+9/15
- Control group+15/15
- Sample size (n=18)+1.7/20
- Follow-up+10/10
100 / 100
23 / 100
- P-values+15/15
- Effect sizeno effect size reported
- Confidence intervalsno confidence intervals
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. The study can establish cause-effect for the effect of whey protein vs carbohydrate on plasma hormone and amino acid responses, but the sample size is small (n=18) and the study is single-blind, which may introduce bias. Additionally, the study does not directly measure food intake or satiety; it measures potential mediators.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding information are disclosed in the provided text.
The provided text is only an abstract and references; the full article may contain additional disclosures.
Key takeaways
- 01
After a whey protein drink, levels of CCK (a fullness hormone) increased at 60-75 minutes, GLP-1 at 90 minutes, PYY at 90-120 minutes, and PP for 15-120 minutes.
- 02
These were all higher than after a sugar drink.
- 03
Ghrelin (a hunger hormone) went down equally after both drinks.
- 04
The increases in fullness hormones were significant but the study was small (18 women).
- 05
The results suggest whey protein can trigger hormones that make you feel full, which could help with appetite control.
Surprising findings
- Ghrelin (hunger hormone) dropped similarly after both whey and carbohydrate preloads, despite whey causing greater saturation of other hormones.Common belief holds that protein suppresses ghrelin more than carbs, but this study found no difference.
- Pancreatic polypeptide (PP) was elevated from 15 minutes and stayed high for the full 120 minutes, whereas other hormones peaked later.PP is rarely discussed in popular nutrition. Its sustained response suggests it may be a key mediator of protein’s satiety effect, possibly more important than GLP-1 or PYY.
Practical takeaways
If you want to feel full between meals, a 45g whey protein shake (about 2 scoops) may be more effective than a 45g carb snack (about 180 calories of maltodextrin or simple sugar).
The study used exactly 45g; typical serving sizes are 20-25g. Effects may differ with lower doses.
medium confidenceTiming your whey protein before a meal (preload) could reduce overall calorie intake by increasing satiety hormones.
This study didn’t measure actual food intake (only hormones). Companion study showed reduced intake, but evidence is indirect.
low confidenceWhy this study matters
The Hormone Symphony of Satiety
After a whey protein drink, CCK increased at 60 and 75 minutes, GLP-1 peaked at 90 minutes, PYY rose at 90 and 120 minutes, and pancreatic polypeptide (PP) stayed elevated from 15 minutes all the way to 120 minutes. Meanwhile, the carbohydrate drink only suppressed ghrelin—a hunger hormone—equally, without boosting these fullness signals.
This explains why protein makes you feel fuller than carbs: it actively turns on multiple satiety hormones, not just one.
Pancreatic Polypeptide: The Unsung Hero
PP was the only hormone that increased from the very first measurement (15 minutes) and remained significantly higher for the entire two-hour study. The authors highlight PP as a particularly robust mediator.
Most people have never heard of PP, but it might be the main driver of protein’s satiety effect. This could shift the conversation from GLP-1 to PP.
Ghrelin: Not the Whole Story
Both whey and carbohydrate drinks lowered ghrelin equally, but only whey increased the other satiety hormones. That means ghrelin suppression alone doesn’t explain fullness—it’s the combination that matters.
It debunks the idea that 'protein suppresses ghrelin better than carbs'. The real difference is in the other hormones.
Want the whole report?
Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Scientists gave 18 women a drink with whey protein or sugar (maltodextrin) and measured hormones that control hunger. They found that whey protein increased several 'fullness hormones' (CCK, GLP-1, PYY, PP) in the blood, while sugar did not. This might explain why protein helps you feel full.
Research results
After a whey protein drink, levels of CCK (a fullness hormone) increased at 60-75 minutes, GLP-1 at 90 minutes, PYY at 90-120 minutes, and PP for 15-120 minutes. These were all higher than after a sugar drink. Ghrelin (a hunger hormone) went down equally after both drinks.
What this means - more context
The increases in fullness hormones were significant but the study was small (18 women). The results suggest whey protein can trigger hormones that make you feel full, which could help with appetite control.
To investigate how ingestion of a whey protein-enriched preload beverage affects postprandial plasma concentrations of satiety-related gastrointestinal hormones and metabolites compared to a maltodextrin carbohydrate-enriched preload in normal-weight women.
In a single-blind, randomized crossover trial with 18 normal-weight women, a whey protein preload (45g) increased plasma CCK, GLP-1, PYY, and pancreatic polypeptide, and also increased total amino acids, urea, and ammonia compared to an isocaloric maltodextrin preload. Ghrelin decreased similarly after both preloads. These hormonal and metabolite changes may mediate the greater satiety observed with whey protein.
Methods Used
18 normal-weight women, single-blind randomized block design, blood samples over 120 min after consumption of 300 ml (~1300 kJ) test drink enriched with 45g whey protein or maltodextrin carbohydrate.
Main Finding
Whey protein ingestion significantly increased plasma CCK (at 60, 75 min), GLP-1 (90 min), PYY (90, 120 min), and PP (15-120 min) compared to maltodextrin carbohydrate. Ghrelin decreased similarly in both conditions. Total amino acids, urea, and ammonia were higher after whey protein.
Confidence Level
Moderate - small sample size (n=18) but randomized and controlled, single-blind, with appropriate statistical analysis.
Study Flags
Red Flags
- •Small sample size (n=18)
- •Only normal-weight women, not generalizable to men or overweight/obese
- •Short measurement period (120 min) - long-term effects unknown
Surprising Findings
Ghrelin (hunger hormone) dropped similarly after both whey and carbohydrate preloads, despite whey causing greater saturation of other hormones.
Common belief holds that protein suppresses ghrelin more than carbs, but this study found no difference.
Practical Takeaways
If you want to feel full between meals, a 45g whey protein shake (about 2 scoops) may be more effective than a 45g carb snack (about 180 calories of maltodextrin or simple sugar).
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study is like a test where scientists gave women two different drinks—one with whey protein and one with sugar—and checked their blood for chemicals that tell the brain 'I'm full.' They found that the protein drink made more of those 'full' chemicals. But this study only looks at what's in the blood, not if the women actually ate less later. So we can say the protein drink changed these chemicals, but we can't say for sure it makes people eat less.
The study has a COI section but no disclosure was found. A small penalty has been applied.
Strengths
- Randomized crossover design
- Controlled comparison
- Measured multiple satiety-related hormones and metabolites
Weaknesses
- Small sample size (n=18)
- Single-blind (not double-blind)
- Short duration (120 min postprandial)
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Scientists gave 18 women a drink with whey protein or sugar (maltodextrin) and measured hormones that control hunger. They found that whey protein increased several 'fullness hormones' (CCK, GLP-1, PYY, PP) in the blood, while sugar did not. This might explain why protein helps you feel full.
Research results
After a whey protein drink, levels of CCK (a fullness hormone) increased at 60-75 minutes, GLP-1 at 90 minutes, PYY at 90-120 minutes, and PP for 15-120 minutes. These were all higher than after a sugar drink. Ghrelin (a hunger hormone) went down equally after both drinks.
What this means - more context
The increases in fullness hormones were significant but the study was small (18 women). The results suggest whey protein can trigger hormones that make you feel full, which could help with appetite control.
To investigate how ingestion of a whey protein-enriched preload beverage affects postprandial plasma concentrations of satiety-related gastrointestinal hormones and metabolites compared to a maltodextrin carbohydrate-enriched preload in normal-weight women.
In a single-blind, randomized crossover trial with 18 normal-weight women, a whey protein preload (45g) increased plasma CCK, GLP-1, PYY, and pancreatic polypeptide, and also increased total amino acids, urea, and ammonia compared to an isocaloric maltodextrin preload. Ghrelin decreased similarly after both preloads. These hormonal and metabolite changes may mediate the greater satiety observed with whey protein.
Methods Used
18 normal-weight women, single-blind randomized block design, blood samples over 120 min after consumption of 300 ml (~1300 kJ) test drink enriched with 45g whey protein or maltodextrin carbohydrate.
Main Finding
Whey protein ingestion significantly increased plasma CCK (at 60, 75 min), GLP-1 (90 min), PYY (90, 120 min), and PP (15-120 min) compared to maltodextrin carbohydrate. Ghrelin decreased similarly in both conditions. Total amino acids, urea, and ammonia were higher after whey protein.
Confidence Level
Moderate - small sample size (n=18) but randomized and controlled, single-blind, with appropriate statistical analysis.
Study Flags
Red Flags
- •Small sample size (n=18)
- •Only normal-weight women, not generalizable to men or overweight/obese
- •Short measurement period (120 min) - long-term effects unknown
Surprising Findings
Ghrelin (hunger hormone) dropped similarly after both whey and carbohydrate preloads, despite whey causing greater saturation of other hormones.
Common belief holds that protein suppresses ghrelin more than carbs, but this study found no difference.
Practical Takeaways
If you want to feel full between meals, a 45g whey protein shake (about 2 scoops) may be more effective than a 45g carb snack (about 180 calories of maltodextrin or simple sugar).
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Human RCT
Subject
Moderate probability
on the GRADE evidence scale
This study is like a test where scientists gave women two different drinks—one with whey protein and one with sugar—and checked their blood for chemicals that tell the brain 'I'm full.' They found that the protein drink made more of those 'full' chemicals. But this study only looks at what's in the blood, not if the women actually ate less later. So we can say the protein drink changed these chemicals, but we can't say for sure it makes people eat less.
The study has a COI section but no disclosure was found. A small penalty has been applied.
Strengths
- Randomized crossover design
- Controlled comparison
- Measured multiple satiety-related hormones and metabolites
Weaknesses
- Small sample size (n=18)
- Single-blind (not double-blind)
- Short duration (120 min postprandial)
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
The study was done carefully: it was a fair test where each woman tried both drinks, and they didn't know which one they were getting. But only 18 women took part, which is a small group, and the test only lasted two hours. A bigger study with more people and a longer time would make the results stronger.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
70 / 100
- Randomization+20/20
- Blinding+9/15
- Control group+15/15
- Sample size (n=18)+1.7/20
- Follow-up+10/10
100 / 100
23 / 100
- P-values+15/15
- Effect sizeno effect size reported
- Confidence intervalsno confidence intervals
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
This design can establish causation. The study can establish cause-effect for the effect of whey protein vs carbohydrate on plasma hormone and amino acid responses, but the sample size is small (n=18) and the study is single-blind, which may introduce bias. Additionally, the study does not directly measure food intake or satiety; it measures potential mediators.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding information are disclosed in the provided text.
The provided text is only an abstract and references; the full article may contain additional disclosures.
Standing
Who’s using this study?
The videos and claims on this site that lean on this study, and the researchers who wrote it.
1 video from Thomas DeLauer cite this study, drawing 1 claim from it.
- Unverified · Lacks evidence
Not enough evidence yet — take this with caution.
Evidence
Authored by
4 researchersIf this is your work, this is how we attribute it on Fit Body Science. Sylvia M. S. Chungchunlam is listed as the lead author.