Protein Supplements

Are protein supplements ok on the ketogenic diet? The short answer is sometimes, and it depends on which ones we are talking about. Let’s dive in a little deeper and and explain that qualified answer.

Protein Supplements

Are protein supplements ok on the ketogenic diet?   The short answer is sometimes, and it depends on which ones we are talking about.  Let’s dive in a little deeper and and explain that qualified answer.

Whey Protein


If you search for whey protein the first description you will find is -  Whey protein is the protein fraction of whey, which is a liquid that separates from milk during cheese production. It is a complete, high-quality protein, containing all of the essential amino acids. In addition, it is very digestible, absorbed from the gut quickly compared to other types of protein.

However, when we are looking at whey from a ketogenic standpoint there are several factors that need to be considered.

Firstly, there are two main types of whey protein.  Concentrate or Isolate. 

For the sake of simplicity, Whey protein concentrate is 70-80% protein and 20-30% milk solids.  It is very inflammatory within our bodies and is something we should avoid.  

Whey protein isolate is 90-95% protein and 5-10% milk solids.  Whey protein isolate has historically been used to build muscle after workouts or as a meal replacement.  Whey protein isolate is also inflammatory without our body.  

Both whey protein concentrate and isolate can create large insulin spikes, because of the high amount of leucine, an amino acid, which in keto stop fat loss.

Both whey protein concentrate and isolate are not recommended on the ketogenic diet.  If you are finding a difficult time getting enough protein the whey protein isolate can be used post-workout, but there are better options available.

Casein Protein

Casein is a slow-digesting dairy protein that people often take as a supplement.

Like whey, casein is derived from milk.  It is a complete protein.


When looking at the ketogenic diet it does not create the same insulin spike as whey however, casein is hard to digest, and during the digestion process, it creates casomorphins which are highly inflammatory.  Another issue is the way it acts within the brain. Casein can create cravings because of the way it’s processed and absorbed. Due to these cravings, and the inflammatory response it can cause casein is not recommended while on the ketogenic diet. 

Pea Protein

Pea protein powder is made by extracting the soluble pea protein from yellow split peas. It is not the same as ground peas as most of the starch and fiber are removed. Yellow pea protein powder is an excellent source of dietary protein for vegetarians and vegans that cannot use animal/milk-based proteins.


Pea protein is not a complete protein, typically you need to add something else like hemp protein to make it complete.

Pea protein has prebiotic fiber, is slow absorbing, and does not spike insulin.  Works well as a meal replacement, and post-workout because it is slow acting. It works very well in a ketogenic diet because it does not spike insulin. But, you need to add another form of protein unless you find on that already has the hemp protein added.

Rice Protein


Rice protein is a vegetarian protein isolate that is an alternative to the more common whey and soy protein isolates. Brown rice can be treated with enzymes that will cause carbohydrates to separate from proteins. 

Rice protein is not recommended in the ketogenic diet.  Rice protein is very inflammatory and acts like gluten the body.




Collagen is one of the most plentiful proteins in mammals. It is responsible for several biological functions, one of which is to provide structural support in connective tissue, muscle, and skin.

In the ketogenic diet, collagen is fine to use as a supplement.  It is not used for muscle building instead it mostly helps, hair, nails, skin, tendons, and repair the small connections within muscles.  It can be added to coffee, tea, pea protein, etc.