The Study
A whey-protein supplement increases fat loss and spares lean muscle in obese subjects: a randomized human clinical study
This study is like a fair test where two groups of people ate the same low-calorie diet, but one group got a special drink and the other got a fake one. The group with the special drink lost more fat and kept more muscle, but both groups lost weight. So the drink might help a little, but it’s not magic—it only worked because everyone was dieting.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
This study tested a special protein drink called Prolibra™ that people drank before breakfast and dinner while eating fewer calories.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 571 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — losing fat while keeping muscle helps you stay stronger, burn more calories at rest, and reduces health risks like diabetes.
- 2People who drank Prolibra™ lost 2.8–3.6kg of fat and only 0.75–1.07kg of muscle, while those who drank the control lost 1.6–2.1kg of fat but 1.55–2.41kg of muscle.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrition & Metabolism
Year
2008
Authors
J. Frestedt, J. Zenk, M. Kuskowski, L. Ward, E. Bastian
Related Content
Claims (6)
People can lose one pound of fat each week while keeping all their muscle mass unchanged.
In obese adults following a 12-week calorie-restricted diet and losing at least 2.25 kg, those who consume 20 grams of Prolibra™ whey protein before meals lose more fat and less muscle compared to those who do not take the supplement.
Among obese adults following a calorie-restricted diet, taking 20 grams of Prolibra™ whey protein daily does not lead to greater total weight loss than a control diet with the same calories, but it results in a greater reduction in fat mass relative to lean mass.
Obese adults on a 500-calorie-per-day diet who take 20 grams of Prolibra™ whey protein before breakfast and dinner for 12 weeks lose 2.81 kg of fat and 0.75 kg of muscle, while those who take a control beverage lose 1.62 kg of fat and 1.55 kg of muscle.
Over 12 weeks, a calorie-restricted diet with 20 grams of Prolibra™ whey protein daily changes the ratio of carbohydrates to protein from 3.6:1 to 2.4:1, resulting in a fat-to-lean mass loss ratio of 3.75:1, while a control group with no change in ratio lost fat and lean mass at a 1.05:1 ratio.
Obese adults who used Prolibra™ whey protein while following a calorie-restricted diet for 12 weeks lost 6.1% of their body fat, which is more than the 5% reduction linked to lower risk of type 2 diabetes and hypertension.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.