The Protein Bible: Part 2 - Protein Powders

By Kurtis Frank and Sol Orwell

The four part breakdown to this protein guide:

After discussing protein requirements, some readers were likely analyzing their diets and thinking: “I need more protein.”

Good sources of protein tend to be meat, fish, dairy, and eggs, and can be divided into whether they are lean protein sources (not too much fat or carbohydrates, just protein) or whether they are not lean (usually half or more of the calories come from dietary fats). The lean protein sources tend to be select cuts of red meat (usually the more expensive ones), chicken, egg whites, and warm water fish such as tilapia or tuna; everything else is usually not lean.

Lean protein sources aside from tuna and egg whites tend to be more expensive than their non-lean counterparts (such as ground beef or whole eggs). This can make it tough to get enough protein but not each too many calories in general.

And sometimes, you just want some sweet chocolate or cinnamon-bun taste while getting your protein in at the same time.

Protein supplements are a simple and tasty way to fulfill protein requirements. They are also pretty cheap on a cost-per-serving basis.

So... what protein powder should you buy?

Whey Protein (and its variations)

Whey protein is a component of dairy protein, and is specifically the 20% of the protein fragment that is water soluble. It’s true definition is “the group of milk proteins that remain soluble in milk serum or whey after precipitation of CN at pH 4.6 and 20°C” (USDA definition). Basically, when you process cheese, you end up with “curds” (found in poutine) and “whey.”

Whey protein can come in a ‘concentrate form’ (35-80% protein by weight), an isolate form (more than 90% protein by weight), and a hydrolyzed form (predigested with acids). Beyond this, different processing techniques such as cold processing or micro/ultrafiltration are sometimes used, and the combination can lead to fancy label terms such as “Cold-processed microfiltration whey isolate”.

Practically speaking, there is not much difference between whey concentrate or whey isolate. If isolate is 90% protein by weight and your concentrate is 80% protein by weight (just read the food label), then the 10% difference is actually quite small (in a 24g scoop that is less than 3 grams).

Hydrolysate is quite different, as the acid hydrolysis (predigestion) breaks down the amino acids so they can be digested faster (it also makes them really bitter). Hydrolysate is mostly beneficial for those with immune problems since it is non-allergenic, and this non-allergenicity is why it is actually used in baby food! It is also currently the most expensive variant of whey protein.

Whey protein is the water soluble parts of dairy protein, and is considered one of the standard dietary supplements. It can be found in three main forms, and while there isn’t too much difference between concentrate and isolate, hydrolysate is unique.

While we will get into the speed of absorption in the fourth timing (“Protein Timing”), your primary consideration should be taste and cost. Whey has been on the market for a long time, and you can find dozens of unique flavors. It’s definitely the protein source for beginners.

Whey protein is a cheap and (potentially) delicious source of protein.

Casein Protein (and all its variants)

Casein is the typical “slow absorbing protein”, and the “curds” that are separated from the “wheys” in cheese making refer to the casein component. Casein has a special property of being able to form gels when liquid is added, which is unique among protein sources (and a reason casein was once used to make glue).

Similar to whey, casein comes in a few forms. The main three are calcium caseinate (the basic form), micellar casein (a purer form of casein), and hydrolyzed casein. The first two are the ones that give you gel-forming (thickening) properties, whereas hydrolyzed casein does not form gels at all (in fact, hydrolyzed casein is very water soluble may be absorbed a bit faster than hydrolyzed whey)!

Casein (referring to the slower variants) may be slightly better than whey at promoting muscle mass over the long term, but the difference is pretty small.

The main benefit of casein protein is its gel forming properties. This is unique to casein protein and things that contain casein, and lets you make a thick shake, pudding, or other desserts (want some recipes? Check out Protein Pow or Get Zomt to start).

Casein is likely the best protein powder to use in baking.

Milk Protein

Milk protein is a less processed and usually cheaper variant of dairy protein, and is very similar to the protein found in milk already (around 80% casein to 20% whey). Its properties are similar to casein, and it can be cheaper than casein.

There is nothing really special about milk protein if you were to compare it to casein, as since milk protein is usually 80% casein they are similar in physical properties and the effects on health. There may be some beneficial effects from combining whey and casein protein (limited evidence on this topic), and hilariously enough there are some products that will buy isolated whey and casein to then reintroduce them in a special ‘blend’.

In a sense, milk protein is dehydrated milk but with the additional carbohydrates and fatty acids removed. Sometimes that is all you need for a protein supplement.

A cheap and effective way to get casein protein.

Soy Protein

Soy protein is a protein source that is derived from the soybean, and comes in two forms: soy concentrate and soy isolate. There is a bit of a difference between these two, and the difference tends to lay in the soy isoflavones (the plant based estrogen mimetics called genistein and daidzein).

The requirement for something to be called soy isolate is that it has a high percentage of protein by weight with no other specific processing requirements. Soy isolate tends to retain the soy isoflavones, but to around 38-46% of what is found in the soybean.

Alternatively, soy concentrate is extracted with solvents (usually hexane or ethanol) which removes all the soy isoflavones from the final product. Even in the worst case scenario of soy being estrogenic (we’ll get to that), it should not apply to soy concentrate since it has no isoflavones.

Now... on the topic of soy isoflavones and estrogen (we’re about to get a bit science heavy): soy isoflavones are best described as selective estrogen modulators (SERMs). They are pro-estrogenic in states of estrogen deficiency (such as menopause) and anti-estrogenic in states of estrogen excess (usually youth). These are generalizations.

In the case of men taking soy, as they are not in a state of estrogen deficiency, there is no reason why the SERMs would have a negative effect on your testosterone levels. Funnily enough, genistein (a soy isoflavone) is also a weak selective androgen receptor modulators (SARMs), and thus can actually increase the signalling of testosterone in states of testosterone deficiency (such as such as hypogonadism or older age [1] ).

If soy protein could negatively impact your testosterone levels, it would only be able to do so because you are doing everything else wrong (diet, exercise, and sleep).

Soy protein is a viable form of protein that will not send your testosterone levels plummeting nor your estrogen skyrocketing.

Hemp Protein

Hemp protein is a protein source derived from hempseeds. Unlike many of the other protein sources mentioned, it is not a lean protein source. It makes up for this by being a good source of dietary fiber and is touted to have a balanced omega-3 to omega-6 fatty acid ratio.

There are not many studies on hemp protein, but it does appear to be an alternative protein source. It doesn’t currently have too much going for it, as a balanced omega-3 to omega-6 profile is not necessarily something you if your diet isn’t perfect (most people get enough omega-6s and just need more omega-3s), and while fiber is always a good thing, putting it in your shake can decrease taste and make it extremely thick.

Hemp protein does contain a small amount of cannabinoid compounds, but the main one (THC; the most active component of marijuana) is not present. The activity of the other molecules is not yet known, but studies on hemp oil itself did not show much promise.

Hemp protein’s balanced fatty acid profile is overrated, and so are the rest of its benefits. It’s only extra is fibre.

Rice/Pea Protein

Rice and Pea protein (a 50/50 mixture of both) is a relatively pure protein source that is seen as so complementary they are grouped together. Rice is a smooth tasting and highly soluble protein source (but is incomplete), and pea completes this protein source while conferring some gel forming properties.

The final mixture has a relatively balanced taste profile and has an amino acid profile scarily similar to whey protein; due to that, it is sometimes called ‘vegan whey’ and used as a replacement for whey due to it not being allergenic.

There are not too many studies conducted on the combination and there aren’t really any known additional bioactives in this protein that makes it ‘special’.

Rice/pea protein is a cheap source of protein that is palatable, vegan, and non-allergenic which makes it a solid alternative. However, aside from it being suitable for the lactose intolerant and those with allergies there are no other known benefits of this combination over whey.

Egg Protein

Egg protein is literally the protein from egg whites in powder form, although some brands may add in some extra nutrients to boast about having the nutrition of an egg yolk. In the situation of added nutrients the egg protein may be more nutritious than other protein sources.

A marketing strategy for egg protein is to boast about how it is the reference protein for bioavailability rates. While this is true, it’s useless for two reasons:

  1. It’s the reference because we hadn’t tested whey. While egg sits at 100, whey protein is at 120 - 20% more bioavailable
  2. Based on our recommendations from Part 1, you are eating more than the RDA anyway. Thus no worry about bioavailability too much

There always appears to be a subtle egg taste in egg protein sources, which unsurprisingly may ruin some flavors and turn people off from using the protein.

Derived from egg whites, it doesn’t taste very good and doesn’t seem to have any real benefits.

Beef protein

Beef protein made a recent return to the market, and it was somewhat of an overrated return. This could have been due to:

  • Initially being blueberry flavored
  • Processing beef into a powder is expensive
  • It kind of takes away the essence of “meat”

All protein sources have a special amino acid profile. This usually is a concern when it comes to seeing if a protein source if complete or incomplete, but it may be used fallaciously to gauge how effective a protein is. There is nothing special about the amino acid profile of beef.

Now don’t get me wrong, beef itself is great and probably preferable over supplemental protein powders. However, this is due to many nutrients found in beef (creatine, carnosine, a bit of beta-alanine, arachidonic acid, etc.) that have not specifically been re-added into beef protein.

Due to the recency of it, beef protein has not yet been evaluated scientifically. It also does not appear to have any specific reasons to use it either, and should be avoided for the time being.

Read more of the protein guide:


Kurtis Frank and Sol Orwell founded Examine.com in early 2011 to help make sense of scientific research on supplementation and nutrition. Independent and unbiased, they recently have released the Supplement-Goals Reference in order to make it easy to figure out which supplements work (and which are hype).

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