For today’s edition of Dear Mark, we’ve got a two-parter. First up, I respond to a comment from last week’s Weekend Link Love concerning fat gain and lean mass loss in taekwondo athletes*on a ketogenic diet. Did the athletes actually get fatter and lose muscle on their diet, even as performance improved? After that, I discuss what to do about dandruff and an itchy scalp. There may be no silver bullet against the common malady known as dandruff, but there are a few things you can try and one in particular that looks quite promising.
Let’s go:
That Taekwando study was posted on Free The Animal awhile ago. The conclusion:
“”Keto” Diet in Taekwando Athletes: Good for Performance, Less Beneficial for Body Composition – Non-Sign. Higher Muscle & Lower Fat Loss in 25% Deficit vs. Balanced Diet”
“Performance” is relative. A ketogenic diet is often detrimental to athletic performance. What’s interesting is that the athletes got fat on said ketogenic diet.
I’m really glad*this was mentioned. Here’s the study (PDF).
Let’s say you’re right and these martial artists did get fat and lose muscle. They did all that while improving their 2000 meter*time and reducing their anaerobic fatigue during a Wingate test (probably the toughest sprint workout ever conceived; puke buckets adjacent to the cycle ergometers are standard, to give you an idea of how tough it is). Isn’t that amazing? I mean, if they were really getting fatter and atrophying muscle mass, shouldn’t their performance markers decline?
Anyway, in the authors’ own words, the changes weren’t significant enough to mention in the results. And the method used to determine the changes, as you’ll find out, wasn’t very accurate.
The study used bioelectrical impedance analysis (BIA) to determine the athletes’ changes in body composition. This is problematic for several reasons:
BIA just isn’t accurate when it comes to measuring the loss or gain of lean body mass during weight reduction. Changes in lean body mass are consistently overestimated using BIA,*especially in ketogenic dieters.
Researchers have dubbed BIA invalid for assessing lean body mass in athletes; the fluctuations in water weight throw off the results. Even “small fluid changes” are incorrectly interpreted as changes in body fat content. It simply doesn’t work.
Ketogenic dieting (and low carb dieting in general) is famous for the massive drop of water weight that occurs in the first couple weeks. For every gram of glycogen they store, our muscles retain three grams of water (PDF). As we lose muscle glycogen, either from training or going low-carb, we flush water out.*This is all normal, and it’s often used to disparage the weight loss effects of low-carb diets (“Ah, you’re just losing water weight!”). Since BIA interprets water weight as lean mass, this makes*a BIA-derived assessment of body fat unreliable.
There is another, better method for testing changes in body fat in athletes: the skin fold measurement. In studies directly comparing the validity of body fat measurements in athletes using skin fold measurement or BIA, the former*always wins out*and BIA overestimates body fatness.*Let’s see what happens when you test the effects of a ketogenic diet on body composition and performance in elite athletes (gymnasts, in this case) using skin fold measurement. Back in 2012, Paoli used skin fold measurements to track changes,*finding that ketogenic athletes lost body mass, lost body fat, and gained a small amount of lean mass while suffering no decrease in physical performance.
There were some differences between the gymnast keto diet and the taekwondo diet. The TKD diet was 55% fat and 40% protein, probably too high in protein to be truly ketogenic. The TKD athletes also restricted calories by 25%, while the gymnasts ate as much as they desired.
The athletes didn’t get fat, then. And performance is “relative,” I suppose, but that doesn’t invalidate the results. “Relative” to the non-ketogenic dieting athletes, the keto athletes’ performance increased. Relative to their own previous performance, the keto athletes’ performance improved. I don’t see that as a mark against their results.
Now, I’m not suggesting you can’t gain fat on a ketogenic diet. You certainly can. I’m just showing that this study in Taekwondo athletes on a ketogenic diet isn’t strong evidence in favor of it.
Hi Mark,
Thanks for the site; I love it and use it to great extent with friends and family.
I’ll keep it simple: I’ve had an itchy scalp (lots of dandruff, insane itching, dry patches) for about four years, and am currently keeping it under control with medicinal shampoo prescribed by the doctor. Primal doesn’t seem to stop it; and the moment I stop using the shampoo it comes back.
The medicinal shampoo has a 5% alcoholic coal tar extract in it as well as lots of scary ingredients like parahydroxybezoates.
Is there anything I can pinpoint the problem to – and also should I be trying to get off this shampoo ASAP because of what its active ingredients are?
Many thanks,
Andrew, UK
You could try a more “natural” alternative with fewer offensive ingredients, like Grandpa’s Pine Tar shampoo. It’s designed to work against dandruff, though some people may have allergic reactions to it.*Over the counter coal tar shampoos are out there, too, so you could hunt around for one without the ingredients you don’t want.
You could do what the subjects with itchy skin and dandruff did in this study: mix raw honey with warm water (9:1 ratio, enough to make the honey nice and runny) and apply it to the affected areas every other day, making sure to rub it in for three minutes, and letting the honey solution sit on their scalps for three hours before rinsing. Big time commitment, yes, but it worked; everyone improved. After treatment, members of the honey group underwent a second trial to determine the prophylactic efficacy of honey. For six months, half of them*applied the honey solution once a week. None of the honey group had a dandruff relapse, while 12 of the 15 from the group who did not use honey suffered relapses 2-4 months after the initial honey treatment.
You could do what an employee of mine did to fix his dandruff: regular ocean plunges. He’d wade out in the water, dunk his head, and scrub like crazy. An added benefit, according to him, is that the sea water gives you awesome looking hair. Worth a shot, if you’re within reach of an ocean. And if you’re not, he said he’d often “recreate” the ocean water by mixing sea salt and trace mineral drops in a glass of cold tap water.
A lot of people swear by apple cider vinegar hair soaks.
I’d say the honey looks like a good bet, if you’re willing to put in the time. Good luck!
Thanks for reading, everyone. If anyone has a dandruff/dry scalp solution that worked for them, please comment!

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