Some research has shown that ingesting whey protein prior to meals will help you feel more satisfied and consume less total calories. Over time, this can lead to meaningful weight loss (2, 3, 4).
Researchers out of the Queensland University of Technology wanted to test that notion for themselves.
The catch however was that they wanted to see if only 20g of protein, ingested prior to meals would reduce intake, as higher doses have shown it does.
One major argument is the idea of finding the minimal applicable dose, meaning what is the minimum amount of a substance I can take, and still see benefit.
That’s exactly what the researchers aimed to determine.
Ten male participants were recruited for the study.
After an overnight fast, participants reported to the lab fasted. 1 hour after consuming an ad libitum (unlimited) breakfast, participants either consumed 20, 40, 60 or 80 grams of whey protein. (To emulate having a protein shake in between meals as many athletes do).
Immediately prior and after breakfast as well and in thirty minute intervals for 3 hours, subjects had appetites measured using a visual analogue scale (pick 1-10, 1 being hungry, 10 being satisfied).
This was until subjects consumed an ad libitum lunch, with energy intakes calculated.
According to the study, ingesting whey (in any dose) resulted in significantly less calories consumed, but there are a few caveats to this conclusion, which I will get to in a second.
Additionally, when using scales of subjective hunger, there were no significant differences between groups (different doses of protein).
Issues with the study
1. There was no control group.
This can be a big issue for studies that are specifically testing the use of a supplement to “achieve something.”
It’s a problem because you don’t know if the same result would have been seen WITHOUT using the supplement. That doesn’t mean the results are moot, it simply means that NOT using a whey shake could potentially have the same effect (i.e. no effect of using whey).
2. Low amount of participants.
Things like hunger vary widely between individuals. My feelings of hunger after meals of varying complexity will likely be much different than yours.
This study only used 10 participants, meaning that there were not many participants in any of the testing groups.
Again, this doesn’t make the results useless, just less powerful.
3. Method for determining less food was not optimal.
Their measure of “consuming less food” was taking estimated daily energy requirements (for two meals) and comparing that to calories consumed, relative to consuming the protein.
Again, there was no control group to compare to. They are simply guessing how many calories are required and then comparing it to calories actually consumed.
What if someone just didn’t like the food provided and ate less because of THAT rather than because of protein?
4. Not much else.
Really, otherwise there aren’t many issues. No control is a big one, but otherwise the results are not surprising apart from higher doses having no additional effect.
I’d argue, dosage aside, the use of a protein supplement in between meals, and then observing intake afterwards is fairly realistic and may provide a way for people to consume less calories in all.
The reality of it all
The results aren’t surprising. Protein has been shown time and again to be satiating meaning you’ll feel more satisfied and consume less food.
However, the findings aren’t super strong due to control issues. Chances are, in the real world, consuming 80 grams of protein WILL probably beat out only 20 grams.
However, unless you’re a 110 lb. woman, drinking your protein will likely have minimal effect on food intake, albeit probably some. I’d imagine you’d see greater appetite suppression if you ate a whole protein source (like meat or another solid protein). The nature of how the protein is structured slows digestion down, providing increased feelings of fullness.
Why this should matter to you
It matters because it furthers the notion that protein is satiating. When you’re trying to lose weight, increasing your protein intake will be beneficial for muscle preservation/growth in addition to helping you stay satisfied.
Additionally, it reveals that a dose as small as 20 grams of whey MAY have an impact on feelings of hunger. I’m guessing that doing so ACTUALLY DOES have some effect on hunger but will vary as widely as everyone’s individual appetite.
If you want to consume less calories (essential for weight loss) then consuming 20 grams of whey before meals will likely help you consume less in addition to increasing protein intake.
I’d suggest starting with the low dose and see how it affects you. If you find that 80 grams does in fact not differ from 20, try using a solid protein source in it’s place.