Sodium caseinate and whey protein responses in adults
What it found
In healthy and prediabetic adults, drinks with sodium caseinate or whey protein plus carbohydrate lowered peak blood glucose by 21% and raised peak insulin by 96% compared with carbohydrate alone, with no difference between the two proteins.
The trial was in people.
What they found
Studies in people
Gastric emptying
No evidence was found that gastric emptying was different between the 2 protein drinks.
Insulin and glucose
Both proteins increased peak plasma insulin concentrations in prediabetic persons by 96% compared with MD19, which was accompanied by a reduction of peak venous blood glucose by 21%, without a difference between the 2 proteins.
Glucagon
Peak plasma glucagon concentrations increased by 101% in both groups after the protein drinks.
GIP in healthy volunteers
The WPI drink also increased peak plasma glucose-dependent insulinotropic polypeptide concentrations in healthy volunteers by 56%.
Metabolite differences
Differences in plasma metabolite concentrations in volunteers could be attributed exclusively to the differences in the amino acid composition of the 2 proteins ingested.
What the authors conclude
“The WPI and the SC drinks similarly reduced postprandial glucose excursions when ingested with carbohydrates in healthy and prediabetic volunteers.”
Also in their conclusions
- They conclude that the WPI and the SC drinks similarly reduced postprandial glucose excursions when ingested with carbohydrates in healthy and prediabetic volunteers.
- They state that under their experimental conditions, however, no evidence was found that gastrointestinal processing of the 2 protein varieties differed substantially.
How it was done
Casein is considered a slowly digestible protein compared with whey protein, and this may cause differences in hormone responses and the kinetics of delivering amino acids into the circulation.
White healthy male adults (n = 15) and white, well-defined male and female prediabetic adults (n = 15) received test drinks randomly on 3 different occasions at least 2 d apart. The drinks contained 50 g of maltodextrin19 (MD19) alone or with 50 g of whey protein isolate (WPI) or 50 g of sodium caseinate (SC). Blood samples were collected over a 240-min time period.
What it can’t tell you
- We summarised it from the abstract only.
- The trial was small, with 15 healthy and 15 prediabetic adults, so results may not apply to other groups.
- It only tested one dose of each protein with one type of carbohydrate, so other amounts or combinations may give different results.
Who paid
- Authors work at
- Central Institute for Nutrition and Food Sciences, and; Technische Universität München, Germany
The paper
- Title
- Metabolic responses of healthy or prediabetic adults to bovine whey protein and sodium caseinate do not differ
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Hoefle AS, Bangert AM, Stamfort A, et al (2015). Metabolic responses of healthy or prediabetic adults to bovine whey protein and sodium caseinate do not differ. The Journal of nutrition. doi:10.3945/jn.114.199190PubMed 25733461DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error