June 11, 2015

Deja Vu All Over Again - Keto vs Carbs: STOP IT ALREADY!

How many times am I going to have to write this blog post?

More than once, it seems, since it failed to have the desired impact last time I wrote it.

(BTW: I can’t help thinking of that line from Aladdin, where Jafar says to Aladdin, “How many times do I have to kill you, boy?!”)

Am I the only one who feels like the more we learn about biochemical individuality, genetic polymorphisms, epigenetic triggers, the whole-body microbiome—i.e., things that make people differentthe harder and deeper the warring nutritional factions dig their heels in, hold their positions, and stand their ideological ground in insisting that we are all suited to thrive on one type of diet? When we constantly discover downstream effects of differences in biochemical pathways and mechanisms such as methylation, starch digestion, liver detoxification, and muscle fiber distribution (i.e. fast-twitch versus slow-twitch fibers), shouldn’t that make us more open-minded, rather than less, about the different diets on which individuals might thrive?

Maybe I am alone in thinking this. It sure feels pretty lonely out here on this limb.

But since it didn’t seem to sink in the first time I wrote about this, here we go again.

Why is it so difficult for people to wrap their heads around the possibility—just the mere possibility—that there in fact, really and truly are people who thrive on higher amounts of carbohydrate in their diet, and people who thrive on lower carbs? And I’m not even factoring in exercise here. I’ve written in the past about high-intensity exercise being powered more by carbohydrate than by fat and ketones. That being said, there are people engaged in some pretty intense stuff who are doing so on very low carbohydrate (VLC) diets, and managing just fine. (Of course, they tend to take in massive amounts of calories, so it may be that their absolute amount of CHO is actually kinda high, even while the percentage of calories from CHO remains low). But there are also people—really friggin’ smart people—who know about this stuff, and who know their own bodies, and claim they do not demonstrate optimal physical performance while keeping carbs low, even after allowing for a period of adjustment. (This guy comes immediately to mind.) Who am I to say they’re “doing it wrong?” And who is anyone to tell me that this isn’t true for me:

Human beings do have biochemical differences that account for variations in what is “optimal” for us, and what will allow us to thrive. And let’s be clear: there is a difference between surviving and thriving. I think that, to some extent, we can all survive on high carbohydrate intakes, and we can all survive on very low carbohydrate intakes. But thrive? Attain and maintain our best level of metabolic health, physical energy, and psychological & emotional fortitude? That, I’m not so sure about.

The first twenty-five-ish years of my life were proof that I could remain alive and functioning pretty darn well consuming a diet that included lots of grain, low-fat dairy, and a lifetime quota of buffalo chicken sandwiches and seasoned fries. (Forgive me world, for I had sandwich-sinned, hehheh.) But after transitioning to low carb, my health and wellness have reached new heights. I’m a work in progress, and I’ve got a ways to go, but for me, at this point, a low-carb approach suits me best. Could that change at some point in the future? Yes, and I am open to that possibility, because I am not permanently marking my territory on the nutritional battlefield. If the flag needs to be moved, I’ll move it. But who is anyone else to tell me that I do not do best this way, at this point in time? Who is anyone else to tell me that I “should eat potatoes, pineapples, plantains, and millet? 

It is indicative either of ignorance and stupidity, or of refreshing level-headedness, that I am not dogmatic about low-carb. I think there certainly are situations where we can evaluate someone’s diet and lifestyle and find reasons why maybe they are “doing it wrong,” and by tweaking a few things, we can get them feeling like a million bucks without their beloved beans and rice (not to mention whole grain bread). But I also believe there are people who won’t be their best selves on a VLC diet, no matter how well-planned it is, or how perfect they are at sticking with it.

Here’s why I am open-minded about these issues:

The more I learn, the less I know.

So much of what I learn only raises more questions for me. So, either I am a simpleton, and a fairly stupid one, at that (a possibility that I do not at all dismiss), or I am trying to integrate the little details and the big picture, trying to find ways to make them fit together, and I am finding it's a lot more complex than most people want to acknowledge. (Especially the ones who want to sell you their quick fat-loss fix for just $19.99 -- but hurry and buy now, because the deal ENDS SOON!)

What I do know for sure is, my open-mindedness here actually causes me a great deal of self-doubt, to the point that I have considered taking down my shingle and ceasing to provide nutrition consultations. I am in the midst of a crisis of confidence, and I’m not afraid to say so.

But I’m doing that thing again—going off on a tangent. So let’s steer this back to the issue at hand: lower versus higher carbs, round two.

Like I pointed out the first time around, people do have genetic differences that influence their response to various macro- and micronutrients. For example, differences in copy number of genes that code for salivary and pancreatic amylase enzymes affect digestion of starch, which may have an influence on someone’s propensity for obesity, particularly when that someone consumes a high-starch diet. People differ in their sensitivity to substances such as codeine and caffeine, which is why some of us can drink a cup of strong coffee and go right to bed, while others are bouncing off the walls after a small square of chocolate.

Pharmacologists have long understood that people differ in the activity of certain enzymes of the liver’s cytochrome P450 system, making them “fast” or “slow” metabolizers of certain substances. (This is quite relevant to dosing pharmaceutical drugs, as the potency and half-life of drugs in the body are at least somewhat dependent on how quickly or slowly someone’s liver gets rid of them.) Studies in animals suggest that some enzymes also have gender-dependent differences in expression.

So why does it remain so hard for people—even some of the pros, whom I deeply respect—to entertain the possibility that human beings might differ in gene copy number for, or ultimate efficacy of, enzymes involved in biochemical processes that make VLC diets effective, such as gluconeogenesis, lipolysis, and ketogenesis? What about pyruvate carboxylase? What about phosphoenolpyruvate carboxykinase (a.k.a. PEPCK)? What about carnitine acyltransferase? What about genes that code for the proteins that build the monocarboxylate transporters that actually get ketones into cells? We know that certain population groups possess genetic constitutions that make them better or worse suited for particular dietary landscapes. (Peter from Hyperlipid did a great job looking at one such gene regarding genetic adaptations to a high-fat diet among Arctic people.)

If this is something that actually happens—that we are different, on a biochemical basis—then it is entirely possible that some people will feel better on more carbs, and other people on fewer, regardless of the amount or type of physical activity they engage in, and regardless of how much they are NOT “doing it wrong.

This is why it really, really bothers me when people bring up the Kitavans when they say that clearly, human beings can thrive on high starch and high fruit diets. Yes, they can, if they have the genetic makeup of Kitavans. Like I said the first time around, would an Arctic native thrive on the ancestral diet of Pacific Islanders? Even after several months (or years) of time adapt to it? Maybe theres only so much a person can adapt. What would happen if we took a native Fijian and set him/her up in an igloo, with access to the finest seal meat and oolichan grease available? Or set him/her up in Switzerland, with a lifetime supply of the finest cheese and yogurt, from the raw milk of grassfed A2-casein cows? Would that person's Pacific Islander genes thrive on cold climate foods, or dairy? 

Human beings can thrive on a variety of diets. But that does not mean that all humans can thrive on all diets. Different population groups thrive on different diets because they are those populations. WHY IS THIS SO HARD TO ACKNOWLEDGE? 

I want to make it clear, however, that when I say “higher carbs,” I’m not talking about chocolate-frosted breakfast cereal, bottled fruit smoothies, or “breakfast pastries.” I think we could probably make an argument that even people who are physiologically better suited to higher carb intakes are probably better served getting those carbs in the whole food matrix they appear in via, say, parsnips, beets, bananas, and yes, maybe even corn and beans, with their full complement of nutrients and fiber. But corn syrup? Agave nectar? Pop-Tarts? Those, I’m not so sure about. Kind of like how those of us who do well on lower carb and higher fat intakes probably do better when those fats come along with the meat and dairy foods, and nuts & seeds they naturally occur in, rather than wolfing down lots of isolated soybean or corn oil. (I must confess, however, that on occasion, I will eat a small spoonful of bacon fat, butter, or coconut oil all by itself, or add the latter to a cup of coffee. Even so, I’ve always thought it odd to add 3-5 tablespoons of butter and/or coconut oil to a cup of coffee. But hey, it can’t be that odd; if I’d invented the concept, I’d be a multi-millionaire right now.)

Seriously, though. When are we going to stop the carb wars? Why does it threaten someone’s worldview so much when someone else says something they don’t agree with? If that someone else happens to be someone with a great deal of influence in the public health sphere, and that person is insisting that their way is THE way, and the ONLY way, then yes, I could argue we have a professional, moral, and intellectual obligation to stand up for other perspectives and introduce the required degree of nuance into the discussion. But I am hard-pressed to come up with anyone who’s insisting that their way works best for everyone, regardless of anything and everything else we know about genetics and human physiology. And I certainly don’t think it’s worth getting into pissing contests on Twitter with strangers. For every PubMed study you throw in their face, they’ll throw one right back at you. Why bother? Isn’t your time worth more than getting worked up in arguments with people you don’t know and will probably never meet?

I have plenty of free time, but I can find ways to spend it that don’t involve getting angry over this stuff. (Besides, being female, it’s pointless for me to participate in the measuring contests. I’ll lose every time.)

Update: since I penned the draft of this post, the most supremely awesome Sir Wolf has come out with not one, but two things that support the ideas I’ve addressed here: 
  1. Podcast with Dr. Tim Noakes. Most of you in the LCHF community probably know who this guy is, but for those of you who don’t, he’s a South African medical doctor, professor of exercise science, and athletic coach to professional athletes. Once upon a time, he wrote a book about the importance of carbohydrate loading for running, but after stumbling upon the world of high-fat fueling, not just for athletics, but for overall health, he did a 180 with his own diet and that of the athletes he coaches. (Turns out, even with all that running, he was massively insulin resistant and headed for a T2 diabetes diagnosis, and so were many of the people he was coaching.) He is a refreshing voice in this arena, as he has been completely forthright about how “wrong” he was back in the day, even going so far as to basically call entire chapters of his older books complete rubbish. The podcast gets off to a bit of a slow start, but it gets better as it goes on, and they talk about Robb’s challenges in maintaining a high level of athletic performance in glycolytic exercise on a very low carb intake, as well as the genetic differences among population groups as a whole, which might influence their carbohydrate tolerance.
  2. Blog post about his training and diet at the age of 43. I’d say at 8-10% body fat, looking after two children, and with approximately 800 professional irons in the fire, he’s got to be doing something right. The training stuff is less interesting to me than his diet, but it all factors into his overall strategy for maintaining physical, mental, and cognitive health & wellness. (If all you’re interested in is his diet, scroll way down to “Chow” in the link.) Higher carbs and lower carbs have their pros and cons, and he seems to have arrived at a place where he's comfortable eating based on his individual goals and priorities. 

P.S. Regarding “the more I learn, the less I know”: Here are just two examples of the kinds of questions I think about: 1) If long-term VLC diets induce “physiological insulin resistance,” which leaves blood glucose slightly higher than what would be expected, because the muscles become insulin resistant in order to spare glucose for the brain” (or so the theory goes), how long does it take for the brain to take up that glucose? Meaning, if the brain is using that glucose (i.e., taking it in at a pretty good rate), why are blood levels still high? 2) Regarding the correlation of blood, breath, and urine ketones: Urine collects in the bladder for a little while (sometimes hours) before being excreted. How does this affect the correlation between urine acetoacetate levels, breath acetone levels, and blood β-hydroxybutyrate levels? (I would consider the latter two to be more “real-time” measurements, and the former to be a measurement that might be indicative of what the body was doing during the past couple of hours. But I could be entirely wrong. I’m just thinking out loud. Someone who knows way more about this than I do says there’s about a 30-minute lag time between AcAc & B-OHB, so not that big a deal.)

P.P.S. About the fast & slow-twitch muscle fibers: this explains why, with training effort, I can become a faster runner than I am now, but I will probably never be as fast as Carl Lewis, no matter how hard I train. My body literally may not be capable of running as fast as someone else, with different muscle fiber composition & distribution. (Oddly enough, Lewis credited his vegan diet for some of his athletic achievements…) Some of us are built for strength, others for speed, others for sitting on our rear ends, writing blog posts. Hey, one out of three ain’t bad! ;-)

Remember: Amy Berger, M.S., NTP, is not a physician and Tuit Nutrition, LLC, is not a medical practice. The information contained on this site is not intended to diagnose, treat, cure, or prevent any medical condition.


  1. Nice one, so many thought-provoking points. I know what you mean about self-doubt - I get a massive hit of it when blood test results give a number that isn't considered 'normal'.

    I suppose people want certainty before taking the plunge to try something new, which may be why writers title their books with words like "perfect", "secret to" and "the truth about". Maybe they can't wrap their heads around people thriving on a diet that isn't like their 'solution', or maybe they are just giving the market what it wants - certainty.

    Not that there's anything wrong with selling books, of course, and I'm not saying all writers are like that - you are obviously an exception to that stereotypical dogmatic approach.

    "What about carnitine acyltransferase?" Yes...umm, exactly.

    Have a good one.

    1. I'm an exception ... but only because I'm terrible at marketing and figuring out what people would be willing to shell out $$ for. If sales so far are any indication, an e-book about Alzheimer;s ain't it. ;-)

    2. Maybe by the time they need to read your book, they can't?

  2. Self doubt is okay, but please don't stop sharing your knowledge and insight. You have a talent for getting points across to people.

  3. The more we learn, the less we know.... Really?

    The nationwide, large scale, devastating nutritional experiment that the US of A is going through, over the last four decades, is not providing enough basic lessons?

    Isn't this experiment with unknowing human guinea pigs providing overwhelming facts and information that any brain with a minimum reasoning capacity can observe and take lessons from?

    And by knowing more, learning more?

    I don't understand the 'guilt' resulting from observing and understanding what is happening to millions of needlessly sick people. Sick only for what they have been - wrongly - told or given to eat during their lives.

  4. While there are some fearmongers out there, I also think it's important to listen to some voices of reason, and one of those persons I credit as a "voice of reason" is. Dr. Terry Wahls. She was recently featured on the Pheonix Helix podcast "debating" Paul Jaminet about ketosis. It wasn't much of a debate, because they agreed quite a bit. While I don't worry too much about developing worms or drying up my mucous (Jaminet's claims about ketosis), Dr. Wahls had some important things to say.

    Namely, that in her preliminary studies of the Wahls Paleo Plus protocol she was surprised to find that there wasn't a particular advantage to the ketogenic level of her dietary treatment. She herself enjoyed being in ketosis for a long time, but she is now making a point to cycle out of it regularly (with no loss of her good health). And she said that people should be mindful of their personal ancestry when deciding when and how long to be in ketosis--recognizing that we all have genetic variations. She stated that ketosis may be important and useful for the healing phase of the illnesses her diet is meant to treat, but that it does not appear to be necessary to be permanently in ketosis. She also admitted that being in prolonged ketosis may have a negative effect on gut flora, because people typically don't eat enough prebiotic fibers when pursuing a ketotic diet.

    She pointed out that there is not a single traditional culture's diet that is 100% ketotic (not even the Inuits!). "We" often use that statement against vegetarians/vegans (no traditional people live solely as vegetarians) and I think what's good for the goose is good for the gander--she has a point.

    She also pointed out that there are two ways to achieve ketosis: either by reducing carbs drastically which means that you can't eat many vegetables and lose out on the benefits they bring, or add MCT fat as in her Paleo Plus protocol. Jaminet added a third way to achieve ketosis is fasting.

    I've long been skeptical of those who eat only meat and fat and claim that we don't need ANY carbohydrates (make that vegetables). I think we don't even know what we don't know about the micronutrients and other benefits of edible plants. It's my opinion (personal opinion, I have no scientific credentials) that we ignore plants in our diet to our peril. We each have to determine how much plant matter should be a part of our diets, based on our own body's responses.

    Remember, there are no studies showing the long term effects of prolonged, sustained ketosis. And humans have always been omnivores, so while our ancestors may have spent a good deal of time in ketosis, they certainly went for the fruit and tubers and honey if they could.

    I get the tension in the communities. Some of the people claiming ketosis is dangerous are really off the deep end. But that doesn't mean I'm going to close my mind off to legitimate science and explore a little. It's nice to find kindred spirits in this quest.

    BTW, despite the claims about the Kitavan diet, they fail to acknowledge that Kitavans also eat pork (and when you kill a pig in a tropical place, you're going to eat the "whole hog" fast!), fish and seafood. They are NOT vegetarians by any stretch of the imagination no matter what John McDougall would like you to believe.

    1. Thank you, Jan! One of the best comments in the history of this blog. I have mixed feelings about Jaminet, but I can't deny that his program has helped a lot of people who were not getting the results they wanted on lower carb or strict Paleo. The proof is in the safe-starch pudding (hehheh), and he's helped plenty of people find their way back to better health when other strategies weren't working for them. I like Dr. Wahls a lot. Very practical and level-headed. I'll have to give this interview a listen.

      "I think we don't even know what we don't know about the micronutrients..." <---YES!!! (With 3 exclamation points.) I have a blog post in the works about this very thing, in fact -- but not just as it relates to plant foods, but micronutrients in general. I think it'll be eye-opening and give us all a lot to think about. (It's been going around in y my mind for weeks now; just trying to find the time to write the post.) And I have another post that will address the zero-plant thing. (It'll probably be long enough that I'll split it up into 2 or 3.) They're actually somewhat related -- the sources and purposes of the various micronutrients, and how the nutrient requirements of a particular diet are determined, at least in part, by the composition of the diet itself. (Just as one example, there's reason to believe someone on a low-carbohydrate diet has a lower requirement for vitamin C than people eating higher carbs. But there are lots more examples I'll talk about.)

      As for cycling in and out of ketosis, I think that's where the gold is. Or, if not the gold, then at least our distant evolutionary past. Seems like we would have bounced in and out of higher carbs and lower carbs, depending on the seasons. Looked at from this perspective, insulin resistance and non-alcoholic fatty liver are actually evolutionary advantages. Thousands of years ago, they served a beneficial purpose: we fattened up (including our livers) on fruit & starches in summer and fall, as preparation for the leaner times of winter. It was a good thing, back when we probably *needed* a little extra body fat to carry us through. Now, though, as many before me have pointed out, the nutritional winter never comes. In the U.S., we can go to a Whole Foods in Oregon in February and buy mangoes and papayas... In the face of endless sweet & starchy foods, 365 days a year, the physiological mechanisms that used to protect us are now killing us.

    2. Speaking of standing one's ideological ground in insisting that we are all suited to thrive on one type of diet:
      (1) ignore plants to our peril
      (2) better eat probiotic fibers
      (3) better not be 100% keto

    3. I *mostly* agree. Seems like all of the above can be therapeutic for certain people, though -- at least in the short-term. But a short-term intervention intended to bring the body back to some sort of balance can go off the rails when it's continued past its point of utility. Different goals, different stages of life or disease state, different tools. I'm not the best judge of what works for *someone else,* but there are a couple of things out there that are getting pretty wacky.

  5. So what if you are repeating things.

    Repetition leads to mastery and possibly new insight for yourself and those who read what you write. I watched an interview between Charlie Rose and Al Pacino, where Pacino talked about a Shakespeare stage role he performed, well, but it was on the 85th performance that he found a new insight in playing and understanding the role. The audience that night probably equally benefited from his new insight and understanding of a role he had played 84 times before, which has been played by others for over 400 years.

    The constant debate on diet keeps it interesting, and allows the opportunity to reconsider what one has learned and perhaps achieve new enlightenment. Generally takes an open mind though.

    Bet you can write a blog post faster than Carl Lewis. : )


    1. HA! Yes, I can probably out-blog the fleet-footed Mr. Lewis. :)

  6. The idea there are no "long term studies" about being in nutritional ketosis is patently false. There is a multitude of epileptics that have been in ketosis for several decades. the links to such research can be found on ketonutrion.org. As far as the idea that Wolf must be "doing something right" would you extend that concept to individuals who possess 8-10% bodyfat on a SA diet? They exist.Are they doing something right? Robbs genetics have more to do with his leaness than anything else, and the fact he isn't eaten extremely poorly. He's been an athlete all his life. The simplest fact is carbs are the least essential nutrient, with the most abundant health consequences for most people, by far. This instinct and desire that almost everyone has to justify their presence in peoples diets is the true disconnect.

  7. I really appreciate your post here. I am a nurse involved in the nutritional counseling of patients. I am convinced that our individual biochemistry is a main driver of our experience with food. Losing weight for each patient seems to me to be an experiment of ONE.

  8. Yes, and then we change as we age - found this interesting : "Age-Specific Nutrition
    PF as well as TRF and IF can have profound beneficial effects on the health of rodents and humans. However, most of the studies testing these interventions have been performed in young organisms or have not compared their effects in young and old. Understanding the age-specific effects of these interventions is particularly important considering the major changes in weight, growth hormones, and steroid hormones that occur at different ages and the studies indicating that certain restriction can be beneficial or have no negative effects in young, but not old, organisms.
    For example, severe protein restriction causes weight loss in old, but not young, mice, and low protein intake is associated with protection from mortality in 65 and younger, but not 66 and older, individuals (Levine et al., 2014). Similarly, FMD cycles were highly protective in middle age and old mice, but 4 (but not 3)
    days of the FMD appeared to be detrimental in very old mice(Brandhorst et al., 2015). These studies indicate that dietary interventions in rodents and humans must be modified to optimize efficacy in at least two, but possibly more, adult age ranges, with results indicating that the 65–70 age range represents a key transition point. This is clearly an area of longevity research in need of a major expansion of both basic and clinical investigation." http://www.cell.com/cell-metabolism/pdf/S1550-4131(16)30250-9.pdf