Protein and ketosis
Although there are no hard and fast rules for how much protein can inhibit ketosis, some
individuals have reported trouble maintaining ketosis if they consume too much protein per day,
or even excessive amounts of protein at a given meal. To the contrary, some individuals have
eaten 1.2 grams protein/lb or higher and had no problems establishing and maintaining ketosis.
This may be related to the glycogen depletion caused by weight training. In a depleted
state, incoming carbohydrate is used to refill muscle glycogen before it is used to refill liver
glycogen. In essence, the depletion of muscle glycogen provides a ‘sink’ for excess glucose
produced from dietary protein or carbohydrate intake.
Type of protein ingested
The amount of protein calculated in tables 2 and 3 is predicated on the consumption of high
quality proteins such as animal flesh, eggs, and dairy products. The nature of the ketogenic diet
almost ensures that protein intake is from high quality proteins. Many individuals choose to use
commercial protein powders as a protein source and there are many different products available.
The only exception is certain liquid protein preparations which sometimes use low quality
protein (such as collagen or gelatin) fortified with one or more AAs (generally tryptophan).
As detailed in chapter 7, the deaths associated with liquid very- low-calorie protein sparing
modified fasts may have been related to the use of low quality collagen protein although
insufficient vitamin and mineral intake has also been implicated. As long as high quality protein
and adequate vitamins and minerals are ingested, there should not be problems of this sort on a
ketogenic diet.
Timing of protein intake
For the most part, the timing of protein intake is not an issue on a SKD, except as it
pertains to maintaining ketosis. The nature of the ketogenic diet ensures that protein is
consumed at most meals with few exceptions. Consuming protein immediately after a workout
may help with recovery, as protein synthesis is increased at this time. Typically 30-40 grams of
protein are consumed immediately after training to provide the muscles with AAs for tissue
synthesis.
Summary
Protein intake is a critical aspect of a ketogenic diet to prevent muscle loss.
Approximately 150 grams per day of protein must be ingested to provide enough glucose to
supply the brain and prevent the body from breaking down muscle protein. An individual’s daily
protein requirements are tied to activity level and bodyweight. Those individuals whose activity
and bodyweight result in less than 150 grams of protein per day will need to either increase
protein during the first 3 weeks of the diet or increase dietary carbohydrate to ensure adequate
glucose for the brain.