How much dietary protein is necessary to prevent nitrogen losses

Without going into the details of protein requirements, which are affected by activity and are discussed in the next chapter, we can determine the minimum amount of protein which is necessary to prevent body protein losses by looking at two factors: the amount of glucose required by the brain, and the amount of glucose produced from the ingestion of a given amount of dietary protein.

Both of these factors are discussed in previous chapters and a few brief calculations will tell us how much protein is necessary. In the next section, these values are compared to a number of diet studies to see if they are accurate.

To briefly recap, during the first weeks of ketosis, approximately 75 grams of glucose must be produced (the other 18 grams of glucose coming from the conversion of glycerol to glucose) to satisfy the brain's requirements of ~100 grams of glucose per day. After approximately 3 weeks of ketosis, the brain's glucose requirements drop to approximately 40 grams of glucose. Of this, 18 grams are derived from the conversion of glycerol, leaving 25 grams of glucose to be made from protein.

Since 58% of all dietary protein will appear in the bloodstream as glucose (3), we can determine how much dietary protein is required by looking at different protein intakes and how much glucose is produced (table 1).

Table 1: Protein intake and grams of glucose produced *

Protein intake (grams)

Glucose produced (grams)













* Assuming a 58% conversion rate

Assuming zero carbohydrate intake, during the first 3 weeks of a ketogenic diet a protein intake of ~150 grams per day should be sufficient to achieve nitrogen balance. Therefore, regardless of bodyweight, the minimum amount of protein which should be consumed during the initial three weeks of a ketogenic diet is 150 grams per day.

After 3 weeks of ketosis, as little as 50 grams of protein per day should provide enough glucose to achieve nitrogen balance. The inclusion of exercise will increase protein requirements and is discussed in chapter 9.

Gaining Weight 101

Gaining Weight 101

Find out why long exhausting workouts may do more harm than good. Most of the body-building workout and diet regimens out there are designed for the guys that gain muscle and fat easily. They focus on eating less and working out more in order to cut the excess fat from their bodies while adding needed muscle tone.

Get My Free Ebook

Post a comment