Recommended Dietary Allowance (RDA). For adults, the current RDA for protein is 0.8 grams of
protein/ kilogram of bodyweight (0.36 grams of protein/ lb bodyweight). The RDA assumes a
sedentary lifestyle and adequate caloric intake. Daily protein requirements are modified by at
least two factors: carbohydrate intake and activity level.
Carbohydrate intake
As total carbohydrate goes down, protein requirements will go up (10). By corollary, as
total carbohydrate intake goes up, protein requirements will go down. The reason for this is
discussed in detail in chapter 5. To summarize, without factoring in activity, a protein intake of
at least 1.75 grams of protein/kilogram lean body mass or a minimum of 150 grams per day are
necessary to prevent nitrogen losses during the initial stages of a ketogenic diet.
Activity and protein intake
For years it has been assumed that protein intake at the level of the RDA was sufficient
for all individuals including athletes. Much recent data suggests quite conclusively that athletes
do in fact need more protein than the RDA, in some cases up to two to three times more (11).
Bodybuilders and strength athletes have always consumed large amounts of protein as a matter
of course. However, on a ketogenic diet, too much protein can be as much of a problem (by
disrupting ketosis) as too little protein.
A review of the available research has determined that athletes have protein requirements
as shown in Table 2 (11). While it is arguably more accurate to use lean body mass (LBM) to
determine protein intakes, the difficulty in getting an accurate measure of LBM makes the use of
total bodyweight a better choice. Obviously, if an individual is carrying an excessive amount of
bodyfat, and has an accurate method of determining LBM, protein intake should be based on
LBM.
Table 2: Protein requirements for athletesGrams per pound Grams per kilogram
Endurance athletes 0.54 - 0.63 1.2-1.4
Strength athletes 0.72 - 0.81 1.6-1.8Source: Lemon P. Is increased dietary protein necessary or beneficial for individuals with a
physically active lifestyle? Nutrition Reviews (1996) 54: S169-S175.
How much protein per day?
The most critical time to ensure sufficient protein intake is during the first few weeks of a
ketogenic diet, when the need for protein breakdown to provide glucose is at its highest. After the
first few weeks of ketosis, protein requirements will go down as the body reduces its need for
glucose.