|Can a whey protein appetizer really undo the damage of greasy fast food? Probably not, but it's still interesting to see how it affects the postprandial glycemia.|
The study results are interesting, to say the least...
... and that's not despite but rather because the researchers did not use the usual subjects (rodents, obese individuals or elderly people), but young men (aged 18-29) with a BMI of 18.5-29.4 kg/m². In a randomized cross over design (cross over means that every subject got each treatment - obviously in seperate testing sessions), the subjects drank either...
- 300ml of a 10g or 20g whey protein solution,
- 300ml of a 10g or 20g glucose solution, or
- 300ml of flavored zero calorie water
"Cereals", skim milk, pizza... whey alone won't help to counter that
The Pizza had been prepared "according to manufacturer‘s directions". This means that the reduction in glycemia the scientists observed in response to the protein preload were not because the pizza was still frozen... ok, before I produce even more nonsense, let's take a look at what the whey protein and glucose pre-loads did to the subjects blood glucose responses, right?
|Figure 1: Glucose and insulin levels after pre-load and after meal (mean of 30-230min); all values expressed relative to water control, i.e. +85% would mean "85% higher than during control trial" (Akhavan. 2013)|
- The ingestion of the whey protein triggers a significant increase in insulin - 127% for the 10g and 191% for the 20g dosage.
- Contrary to the glucose infusion there is no exogenous glucose that could lead to a rapid elevation of blood glucose (cf. figure 1, left → pre-values); the minimal increase you see is produced by gluconeogenesis in the liver.
- With the elevated insulin levels, the mean glucose levels in the postprandial phase (30min-230min after the pizza ingestion) is lower with both the glucose and whey preload. The effect is however more pronounced with whey than with glucose. The reason should be obvious: The overall amount of glucose that's got to be stored away is lower.
Insulin? Is that all, or is there more to it?
Now that we have gotten the fundamental mechanism by the means of which "glucose-" and "whey-preloading" before eating pizza can ameliorate the blood glucose surge after the meal, let's take a look at the auxiliary data.
|Figure 2: GLP, GIP, PYY, CCK and Ghrelin levels before eating the pizza; all values expressed relative to water control, i.e. +85% would mean "85% higher than during control trial" (Akhavan. 2013)|
- Akhavan T et al. Mechanism Of Action Of Pre-Meal Consumption Of Whey Protein On
Glycemic Control In Young Adults. The Journal of Nutritional Biochemistry. October 2013 [accepted manuscript]