Hate it or love it, popularity never comes singly.
Hit the ratings and you’ll get your life scrutinized by zillions of zealots. Or, if you’re a whey protein powder, by a myriad of scientific labs.
Which, in the latter case, is a good thing. Due to being the all-time bestseller, protein powders are probably the most well-studied product on the entire fitness market.
Yet, they’re controversial.
Can you take whey protein powders on keto? Will they kick you out of ketosis? Do they have any side effects?
Let’s break it down.
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Is Whey Protein Good for You?
To answer this question, we’ll break it down into two separate ones: “is additional protein good on keto?” and, if yes, “is whey protein better than other powders?”.
Is additional protein good on keto? Or, in other words, should you even start supplementing protein on keto?
This one is simple. Unless you work out and are trying to build more muscle, you shouldn’t take any protein powders at all (with just one exception, see the bottom line).
If you do work out, supplementing protein (especially whey protein) on keto could help.
And here’s why.
Is Whey Protein Better Than Other Powders?
Maximizing muscle growth has many variables in its formula, and getting enough protein is one of them.
If you struggle with poor appetite, supplementing protein can help. But not all powders are created equal.
Many types of protein supplements exist: from plant-based pea, rice, and hemp powders, to animal-based beef, casein, and whey powders.
Plant-based proteins are considered inferior to the others due to the lack of certain essential amino acids. Unless you’re on a vegan diet, it makes little sense to buy any plant-derived protein powder.
The two most well-studied animal-based proteins are whey and casein. They share similar properties: both are complete proteins (contain all the essential amino acids), and both originate from cow milk.
However, they have two major differences:
Digestion rates. Whey protein is more readily digested by the human body and elevates blood amino acid levels much higher but for a shorter period of time, roughly 3 hours. Casein, on the other hand, releases amino acids into the bloodstream more gradually but for a longer period of time, approximately 8 hours.
Amino acid profile. Both of them contain all the essential amino acids, but their proportions differ. Whey powders contain more leucine, which is believed to be the most important amino acid for muscle growth.
With all that said, let’s have a look at the studies.
This study in young men has shown that short-term muscle protein synthesis at rest after whey protein consumption was 93% greater than after casein; after exercise, 122% greater. This study has concluded that casein appears to be the major allergen in cow’s milk, and whey protein is the minor allergen.
It appears that whey protein is more effective and less allergenic.
Nevertheless, when we dive even deeper into science, we see that casein is actually better for reparative muscle synthesis and saving your muscle mass, whereas whey excels nearly exclusively at building more muscle.
Summing up, if we take the entire weight of scientific evidence regarding proteins, it’s safe to say that the real difference between them is negligible. In the long term, what matters most is the total amount of protein consumed.
But since there must be a winner, here’s one last thing to consider:
The protein proportion in cow’s milk is 80% casein and 20% whey; in human milk, 40% casein and 60% whey. And what’s good for the bovine is not necessarily good for the human.
Concretely speaking, whey protein is less inflammatory, which ultimately tips the scales in its favor.
But are all whey protein powders created equal? Let’s find out.
Which Whey Protein Powder Is Better for Keto?
We already know that whey protein is a good thing, and all good things come in fours: seasons, compass directions, classical elements, and Ninja Turtles.
No wonder that commercially produced whey proteins make up a quartet:
- Native whey. Least processed and least researched. Potentially more effective but more allergenic. More studies are needed.
- Concentrate. It’s higher in carbs in comparison with the other forms. By weight, it’s 30–85% pure protein.
- Isolate. Fat and milk sugar are removed, the pure protein rate is 90%+.
- Hydrolysate. Partially hydrolyzed and predigested. Potentially less allergenic but already more expensive.
What is the best option for keto among them?
Native whey is promising, but more research is needed. It’s the least processed, hence more sugar is left and it might not be safe for keto.
Concentrate is well-studied and efficient but has more carbs. It might be beneficial for bulking athletes, but it’s not the best feature for a keto diet.
Hydrolysate is something I wouldn’t recommend spending money on unless you’re allergic to milk-derived products. The difference in metabolism speed is a world away from the difference in price.
The best options for keto are isolate protein powders. They provide all the benefits in the absence of carbs—a regular scoop will contain just 1g total carbs.
So, are all whey protein powders created equal?
Obviously, they aren’t. They also differ in nutritional value, taste, flavor, and price, but going over all that would be too much for this guide.
Just one hint: if you want to avoid paying more for a loud brand-name and get the best bang for your buck, you should check out our guide on the best keto protein powder.
Whey Protein Side Effects
The current weight of scientific evidence says whey protein powders have absolutely no side effects.
Unless, of course, you consume 20 scoops a day for a year. But if you can afford that, you can also afford to pay for a decent health insurance program, can’t you?
For the rest of us—moderation is key. There’s no chance several scoops a day can hurt you unless you already have liver and/or kidney issues or are unlucky to be allergic to protein powders.
The Bottom Line
Answering the questions posed at the beginning of the article:
Yes, you can take certain whey protein powders on keto. They won’t kick you out of ketosis and don’t have any side effects.
In a plethora of various protein powders, which ones belong to the “certain” group? Which one is the best? Find out by checking our keto powders guide.
P.S. If you’re over 30, start supplementing collagen even if you don’t work out. It really works magic on your skin, bones, joints, tendons, and helps reduce visible aging. You’ll find a decent option in our buyers’ guide.