Screw it, here's why he's wrong.
He says:
Humans carry about two grams of creatine per kilogram of lean muscle mass (one gram per pound). The maximum we can put into muscles is about 3g/kg (1.4g/lb)[47]. To hit this level, a 150 pound male would need about 25 grams of creatine supplementation.
That's fine, but then he says:
To increase the amount of creatine we carry to a level above the baseline (1g/lb), we need at least two grams per day for maintenance, plus 0.4g for every lean pound of muscle. For a 200 pound male carrying 60 pounds of lean muscle, a reasonable calculation would be:
(0.4g/lb * 60 lbs)/0.95 + 2g ≈ 27.3g
Is he forgetting that "maintenance" levels does not mean "creatine necessary for everything besides the muscles?"
As I'll show below, a normal diet results in normal creatine stores that are 60-80% saturated. Given that 95% of creatine is found in skeletal muscles, that means that the "maintenance" level of 2g/day (dietary intake) for "normal" function (not ergogenic benefits) is sufficient to reach 60-80% of creatine saturation for skeletal muscle. That's from diet. The goal of supplemental creatine is to get that extra 20-40% saturation.
His calculations are base on the (incorrect) assumption that the baseline level of creatine saturation is 0%, which is asinine.
Furthermore, about about half of the total body pool of creatine is obtained via diet, and the other half is synthesized. Assuming the high-end of the 1-2g/day intake via diet, and another 2g/day via synthesis, that gives 4g/day to reach 60-80% saturation. Let's assume 60%, as that will give us a larger required dose to reach saturation via supplementation. So if 4g gets us to 60% saturation, we need another 2.67g to reach saturation, which makes a lot more sense than 27g, and it is consistent with the literature consensus/recommendation of ~3g/day.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2645018/
I will preface my comments by stating that the following information comes from the Journal of the International Society of Sports Nutrition, from a paper authored by these people:
Richard B. Kreider, Douglas S. Kalman, Jose Antonio, Tim N. Ziegenfuss, Robert Wildman, Rick Collins, Darren G. Candow, Susan M. Kleiner, Anthony L. Almada and Hector L. Lopez
In a normal diet that contains 1–2 g/day of creatine, muscle creatine stores are about 60–80% saturated. Therefore, dietary supplementation of creatine serves to increase muscle creatine and PCr by 20–40% (see Fig. 4.)
The total creatine pool (PCr + Cr) in the muscle averages about 120 mmol/kg of dry muscle mass for a 70 kg individual [7]. However, the upper limit of creatine storage appears to be about 160 mmol/kg of dry muscle mass in most individuals [7, 8]. About 1–2% of intramuscular creatine is degraded into creatinine (metabolic byproduct) and excreted in the urine [7, 9, 10]. Therefore, the body needs to replenish about 1–3 g of creatine per day to maintain normal (unsupplemented) creatine stores depending on muscle mass. About half of the daily need for creatine is obtained from the diet [11]. For example, a pound of uncooked beef and salmon provides about 1–2 g of creatine [9]. The remaining amount of creatine is synthesized primarily in the liver and kidneys from arginine and glycine by the enzyme arginine:glycine amidinotransferase (AGAT) to guanidinoacetate (GAA), which is then methylated by guanidinoacetate N-methyltransferase (GAMT) using S-adenosyl methionine to form creatine (see Fig. 1) [12].
Once muscle creatine stores are fully saturated, creatine stores can generally be maintained by ingesting 3–5 g/day, although some studies indicate that larger athletes may need to ingest as much as 5–10 g/day in order to maintain creatine stores [7, 8, 10, 46, 47, 48].
https://jissn.biomedcentral.com/articles/10.1186/s12970-017-0173-z
