I am pretty sure they have been trying to pretend I don't exist since they turned down my application for the National Team Director position.
Jill Castle is an MS, RDN, and has a website that promotes her two books on childhood nutrition, so I have to say she does have some skin in the game here. I am not really making money on this stuff, but that is beside the point. If she is so highly qualified, why is she making so many strong claims with no sources cited to back her up?
Read her article here at the USA Swimming website.
Her claims I can refute?:
“Both a low-fat diet supports and sustains cardiovascular health, and a high-carbohydrate diet is effective at fueling aerobic-based sports such as swimming.”
Well, actually, most of the gains in cardiovascular health with the low-fat diet come from people paying attention to what they eat and avoiding many of the foods that are obviously less healthy, like fried breading, sweets and sugary drinks. As a matter of fact, this study addressed exactly that, and showed that while many diets made progress when leaving the crazy standard American diet behind, the low-carb diet did better in every measure of cardiovascular health, including more weight lost. The low-fat diet has it's own risks that I would say are worse.
...and on the point of which is better to fuel aerobic-based sports, with the RQ improvements shown in the Manifesto, I would say that fat is the better fuel once adapted. Fat may not generate ATP as efficiently as carbohydrate to fuel high intensity exercise even with fat-adaptation, but if our goal is to train our bodies to draw more power aerobically by converting fast-twitch muscle fiber to become oxidative rather than glycolytic, I would say that excess carbs are adding interference that stands in the way. This guy at Reddit did the complex math and it seems that glucose still wins by a hair, but the increase in hemoglobin due to the high presence of Beta-Hydroxybutyrate (a prevalent ketone body,) probably trumps it in athletics, before even considering the potential change-over in fast-twitch muscle fibers from type 2b to 2a, and the glycogen sparing effect, which would be pretty valuable, not just in racing, but in training as well. My contention is that with a long-enough adaptation, the trade-off is better in the way it actually applies to our sport. Plus, just because you are eating low-carb, it doesn't mean that muscle glycogen is never re-fueled. I am pretty sure that no matter what you eat, during taper with the decreased workload, your muscle glycogen builds back up even if it is done slowly. I truly feel that my Viking Method gives me the best of both worlds and as I have said before, I feel better at high intensity than I ever have.
...and on the point of which is better to fuel aerobic-based sports, with the RQ improvements shown in the Manifesto, I would say that fat is the better fuel once adapted. Fat may not generate ATP as efficiently as carbohydrate to fuel high intensity exercise even with fat-adaptation, but if our goal is to train our bodies to draw more power aerobically by converting fast-twitch muscle fiber to become oxidative rather than glycolytic, I would say that excess carbs are adding interference that stands in the way. This guy at Reddit did the complex math and it seems that glucose still wins by a hair, but the increase in hemoglobin due to the high presence of Beta-Hydroxybutyrate (a prevalent ketone body,) probably trumps it in athletics, before even considering the potential change-over in fast-twitch muscle fibers from type 2b to 2a, and the glycogen sparing effect, which would be pretty valuable, not just in racing, but in training as well. My contention is that with a long-enough adaptation, the trade-off is better in the way it actually applies to our sport. Plus, just because you are eating low-carb, it doesn't mean that muscle glycogen is never re-fueled. I am pretty sure that no matter what you eat, during taper with the decreased workload, your muscle glycogen builds back up even if it is done slowly. I truly feel that my Viking Method gives me the best of both worlds and as I have said before, I feel better at high intensity than I ever have.
“The ability to perform high intensity work is compromised due to decreased glycogen (carbohydrate) muscle stores.”
Ummm… I just covered that-- that was kind of the whole point of the Manifesto—to show that this might not actually be the case. I think I have already presented a pretty good argument there, that with adaptation time even high intensity parameters can improve. Are you gonna tell me that LeBron James isn’t able to be intense in practice and games?
“The negative side effects of the high-fat/ketogenic diet for sport have been outlined in the research and include:”
-dehydration. Yeah. This one I admit. When you no longer store as much glucose, you no longer store as much water... but has there ever been any advice out there for athletes that included drinking less water? Drink when you are thirsty and supplement with electrolytes. You should be doing that if you are eating high-carb too.
-hypoglycemia (low blood sugar): It has been shown repeatedly in studies, not only in athletics but even in starvation as well, that in the absence of carbohydrate the human body actually does a better job of maintaining blood glucose at healthy levels once adapted. When we eat carbohydrates, our blood sugar spikes and dips as insulin fights to regulate glucose levels. When we don't, we stay at a healthy level. Check out this interesting case of a 40 day starvation fast:
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| Not that I am recommending forty days without eating to lose that last few pounds, but hey... it worked for this guy. |
-increased risk of kidney stones. This was a side effect in studies on children using the ketogenic diet to treat epilepsy. In those studies, besides carbohydrate being severely restricted, water was often restricted as well. (As she points out in her article, the ketogenic diet for epilepsy is very different from the one recommended for athletes.) In later studies they have shown that this is not a concern provided that a person is properly hydrated, and in cases where it became a concern a simple prescription of potassium citrate often solved the problem. Many people also assume that since a ketogenic athlete might eat more protein when they cut out the carbs, that this is inherently harder on the kidneys. This is a myth. One meta-analysis found high protein consumption might actually be preventive regarding many of the ailments that standard nutritional hype attributes to it. Mark's Daily Apple does a nice write up here about kidneys and diet. It's worth a read and has great links to back it up too. Even the American Diabetes Association had to admit that low-carb isn't a concern with kidneys after this study comparing LCHF to Mediterranean and Low-Fat Diets.
-acidosis—um, I think she is too educated to be making this mistake. She is confusing nutritional ketosis with ketoacidosis. Silly diet experts. Ugh. There are some concerns with pH levels and those articles often refer to the potential for developing kidney stones as well, but most ketogenic diet resources have tips to make sure this is not an issue. If this is an issue, you most likely have something else going on and the diet helped to expose it.
-weight loss—for most athletes, weight loss is a healthy goal. The trick is to lose the weight in a way that spares muscle mass, which is one of the biggest benefits of the ketogenic diet over a high-carb diet. We have all seen athletes who put in the work but still carry extra weight and can't seem to get as lean as everyone else. Heck, I know a guy who trains for triathlons about twenty hours a week and destroys everyone in the Clydesdale category, but you would think after ten years of bad-ass training he might be close to his old fighting weight, right? Not even close. It is hard to fathom, but carbs signal the body to store fat, and it is amazing how well that can be done even in the face of super high energy burning. This study kind of cracked me up, because they claim their results prove that calories in/ calories out applies for weight loss no matter the macro-nutrient content, but then they are actually showing that when the dieters decreased the carbs and upped the protein and fat, their body composition improved. The excess calories were stored, so technically they didn't lose weight, which I guess proves their point, but if you read it carefully you see that one group ended up leaner and stronger, meaning one group stored their equivalent weight as fat and the other group weighed the same but had less body fat percent and more lean muscle mass. (Those who consumed normal- and high- protein diets stored 45% of the excess calories as lean tissue, or muscle mass, while those on the low-protein diet stored 95% of the excess calories as fat.) Now tell me, is there anyone on a weight loss diet who would be disappointed with their weight not decreasing when it was because they were leaner with more muscle? On the reddit keto forums, if you browse for a while, you will see this very thing over and over... so many people post that they were frustrated with the scale not moving until they realized their pants were looser and they needed a new belt even at the same weight. Are there any athletes out there who wouldn't want this? My recent body composition stats gel with this finding as well, as I have gained muscle without lifting.
-poor growth- The ketogenic diet for epilepsy often has protein severely restricted to prevent gluconeogenesis, or creating glucose from proteins. Sometimes this is enough interference to cause some patients to have a lessened effect in seizure control. This is certainly not the recommendation for athletes, and in her article she even compares this diet to the macronutrient contents of the keto diet for athletes: "The traditional ketogenic diet is a modified blend of nutrients consisting of 90% fat, 2% carbohydrate and 8% protein, and has been used in children with seizure disorders and more recently in the management of obesity and other conditions. The high-fat/ketogenic diet used in athletes and research studies is generally modified to 70% fat, 15% protein and 15% carbohydrate." I am not sure why anyone assumes that eating less carbohydrate would interfere with growth considering that fats and proteins are the building blocks for our cellular structure, but okay... maybe those ultra-healthy eskimo's had loaves of bread stashed somewhere that they hid from the white man when we arrived and started documenting their habits. There is a lot of great farm land up there in the tundra.
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| It is more believable that they had these than that they had wheat fields. |
-high fats (lipids) in the bloodstream—umm… waitamminit. Nearly every study done in the last ten years shows the opposite of this. And even those who are hyper-responders, developing more cholesterol from saturated fats, are typically shown to still have less risk for heart disease over-all based on overall improvement in risk factors when going low-carb. The studies that show increased lipids and risk for heart disease are the ones that increase the fat without significantly reducing the carbs. Recent studies have shown that even with the extreme macro-nutrient ratios of the ketogenic diet for epilepsy, this is not a cause for concern as the elevated cholesterol levels that typically come with the diet in some patients eventually calm down. The only reason everyone thinks that carbs are good for the heart is because fiber can reduce cholesterol. Big whoop... Most ketogenic dieters get more fiber from green vegetables, even without the grains. Also, the health risks of high cholesterol might not even outweigh the health risks associated with high fiber. The meds they give you to control your cholesterol have also been proving to be worse than high cholesterol itself.
Remember this graph from the Manifesto?:
Remember this graph from the Manifesto?:
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| 'nuff said. |
-vitamin and trace element deficiencies— Include your green veggies if you are worried about it, and if you go full carnivore, eat your eggs, sardines, shellfish and liver. It’s as simple as that. I am not sure I have seen a single study that shows these deficiencies even in severely restricted epilepsy patients. As a matter of fact, liver is a better choice for vitamins and minerals than any grain or other plant matter out there.
-anemia-- where is she getting this from? If she is talking Iron anemia-- I am not sure I know anyone who eats more red meat than me, which covers that easily even without all of the other foods I get iron from. B12: fish, shellfish, liver... What about folate?: The low-carb veggies are some of the best for this one. Try spinach, avocado, asparagus-- this one is new to me.
My contention here is not that we have to be in ketosis all the time. Kids do naturally have it easier regarding moving in and out of ketosis as they generally have not developed the insulin resistance levels of most adults. I just think that the standard high-carb recommendations are insane. Come on! 700 grams!? 70% of calories from carbohydrate?! Ben Greenfield recommends between 100-200 grams of carbohydrate for those in endurance training. This recommendation is also echoed by Dr Tim Noakes in a recent podcast about LCHF and children. Dr Noakes even lays out a pretty good argument for why LCHF would be better for kids than the grain-based high carb diet too. There are plenty of articles out there about how to help your kids safely eat a low-carb diet if you take the time to look it up on the Google. To put it simply though, if you cut out grains, sweets and fake vegetable oils you are about 80% of the way there. Does anyone really think that would be bad for kids?
There is a new movie out called Cereal Killers 2: Run on Fat. Please, check it out. This movie features some of the leaders in low-carb athletics. You can also watch part 1 here. They both do a fantastic job of laying out the case for low-carb and are just excellent films that stand on their own merit.
Also, yesterday I was invited to be on the Swimming Science Podcast with G John Mullen, so watch for a link soon!
Also, yesterday I was invited to be on the Swimming Science Podcast with G John Mullen, so watch for a link soon!
