I have recently seen an increased push towards carnivore dieting from some of our group members. I wanted to take the time to clarify my position and also address some of the misconceptions and oversights in this approach, which is very similar to what I did a couple of years ago when the keto-only (no carb days) approach was becoming more popular here.
We are repeatedly seeing this play out: “If some is good, more must be better”. If keto most of the time is good, why not do it all the time? If animal fat and animal protein are good, why eat anything else? 🧐
So I want to take the time and go through what we actually need as PKD patients 🩺 and help you to separate “fad” from fact.

The primary mechanism that helps to reduce PKD kidney size and increase kidney function is fat adaptation. We are simply steering the body away from its primary fuel, which usually is glucose. The metabolism of glucose without oxygen is necessary in PKD to grow cysts. By using another fuel that can only be metabolized with oxygen, we are preferentially feeding healthy cells. We are producing (and eating) less glucose, so there is less fuel for cysts to grow. 💪

Now the first misconception is that absolute ketone levels are an indicator of how well this process is working. This is only correct in the beginning phase (about 3 to 6 months) as the body is not yet fully fat-adapted. It is not using ketones very efficiently, so the increased production can be seen in the blood pretty easily as blood ketones. As the body becomes more and more fat-adapted, mitochondria (the little power plants inside cells) get used not only to metabolizing ketones, which are produced from fat, but they become even more efficient, skipping the need for ketone production altogether by metabolizing fats, or fatty acids, directly for energy. This is true fat adaptation and leads to the same desired outcome, which is decreasing the availability of fuel for cyst growth (glucose) by selectively feeding only cells that are using oxygen for their metabolism.

You can actually “force” your body to produce more ketones by overwhelming your ability to directly metabolize fatty acids. You can easily see this at home once you consume about twice as much fat as combined protein and carbs in any given day (2:1 ratio of fat-to-[protein plus carbs], measured in grams). Focusing on these higher levels of ketones does not confer any additional benefits, as can be seen by the steady level of blood glucose when forcing these higher levels. We are just switching from fatty acid oxidation to ketones that way. I have personally never forced my blood ketones (steady around 0.5-1.2 usually) and I have arguably seen the best results of anyone in this group. (creatinine-eGFR up over 50 points, creatinine 0.66 (low end of the range begins at 0.66), cystatin-C-eGFR up over 60 points)

Now while a high fat-to-protein ratio might not be needed, it can even be detrimental if you are reducing your animal protein intake below optimal levels to reach it. Optimal animal protein intake is essential to our ability to repair and grow the glomeruli, which are the functional filtering units of the kidney. Especially physically active people need more protein than the minimum amount. Somewhere between 0.6g and 1.0g per pound of body weight is considered ideal depending on physical activity. 🏋️

The same can be said for the blanket recommendation to remove vegetables. The most popular reason to remove vegetables is a very individual one, mainly gastrointestinal issues. This is called an elimination diet. A very small group of people is definitely benefiting from this to resolve these issues, but just as much as non-PKD people might not need to be in ketosis much, removing vegetables for most people in our community is going to be detrimental. Most gastrointestinal issues are solved with the bulletproof diet as they usually stem from grains, processed foods, or nightshade vegetables. Non-starchy vegetables 🥬 do not influence blood glucose. If there is a glucose spike after a meal containing only nonstarchy veggies, protein, and fat, it is due to a sensitivity to a specific food and the ensuing cortisol spike raising blood glucose, not from carbohydrates. Foods triggering sensitivities should be removed from the diet and can likely be reintroduced after gut healing has taken place.

The bulletproof diet roadmap puts vegetables with high levels of anti-nutrients like phytates, lectins, oxalates, and phytoestrogens into the yellow and red categories. This is the main reason I recommend the bulletproof diet, as it is the first and only diet that takes all of these into account. Further removal of vegetables that are in the green zone is actually not decreasing the burden of anti-nutrients in any meaningful way. However, it is increasing levels of our own internally produced toxins, mainly endotoxin, in the blood. There are several reasons for this:

• Any high-fat meal increases the migration of endotoxin from the gut into the blood as these toxins use the fat as so-called “lipid rafts” to make it across the gut lining, which is already genetically impaired in the PKD mutation. High-fat meals without fiber lead to higher endotoxin levels in the blood after a meal when compared to meals including fiber.
• Some gut bacteria actually start to feed on the gut lining in the absence of regular fiber consumption 🌱 which we would get from vegetable intake. A prominent example that Dr. William Davis recently mentioned on my podcast is Akkermansia muciniphila (“mucus-loving”). If you have this very beneficial bacteria in your gut, and it is well-fed, it even strengthens the gut lining and produces beneficial short-chain fatty acids. It is correlated with good overall health and glucose control in population studies. A lack of this bacteria is correlated with neurodegenerative and metabolic disease, as well as inflammatory conditions. It became available in probiotic form recently. Now if you do have it, but you don’t feed it enough, these bacteria will turn against the gut lining and weaken it by feeding on its mucus, making it more leaky. This in turn will of course increase the amount of endotoxin in the blood even more. 🤒

Of course, endotoxin is probably one of the main triggers of PKD pathology and one of the main reasons the body produces cysts in the first place: to store away excess endotoxin. This makes it blatantly obvious that we should focus on reducing endotoxin in the blood. Elevated levels of endotoxin are routinely found in PKD patients’ urine, blood, and cyst fluid, among other toxins.

In addition, vegetables are our main dietary source of alkalizing nutrients. Most PKD patients actually have a pH that is way too low, which leads to sluggish activity of enzymes and repair processes. Optimizing pH as well as optimizing body temperature are integral parts to being able to heal optimally. Sometimes a low pH is what is keeping somebody who has been seeing good ketone levels for long periods of time from being able to increase their kidney function and seeing results. As many of you already know, you can measure your body pH by measuring your second morning urine, meaning you get up in the morning, pee, drink a big glass of water and nothing else, no medication, no food, no coffee, etc. and then you pee again after that has run through. That way you can measure what your body does to a neutral substance like water and we can see if it still has to get rid of excess acidity. The target range for second morning urine pH is 6.5 – 7.0.

I pioneered this way back in 2016 upon founding this group and there is good reason that it has caught on in other groups as well. Using a digital meter from an aquarium supplier is best, especially with a spherical electrode.

On a carnivore diet, there are no alkalizing foods – the only option is supplementation with citrate or bicarbonate. Of course, many people are still not even aware of this issue.

There will always be new dietary fads and ideas that need to be scrutinized and evaluated. The question should always be: what is this new change going to improve or add to the equation? The bulletproof diet has stood the test of time as many of the more extreme dietary movements have gradually evolved back to a similar diet design.

It still seems to be the most sensible type of moderation as we are not removing any macronutrient completely but we are choosing the most optimal type and timing for each of them and we know exactly why we’re doing it. 🤓

Anyone proposing changes to this is welcome to the discussion but will need to make clear what exactly is being improved.

In light of this, I am also announcing some changes to the group rules:

• attribution: this should go without saying, but of course, anyone publishing derivatives of my work without proper attribution will be removed.
• Terminology: content claiming any diet is a “treatment” or “cure” for PKD will also be asked to remove these statements. There is a reason I never use these terms. So please use proper language when discussing diet.

We all want to continue seeing progress. New ideas, founded in personal experimentation and science. A free, fair, and open forum for all people and free from dogma. The contents I and many of you have published on this group have shaped the discussion of PKD worldwide in a major way and will continue to do so.

For anyone needing a reminder of the details of the diet that I recommend, I have linked the featured section containing all basic information, as well as my more advanced book, which of course contains everything mentioned in this post and much more, below.

Heal well. ❤️
Felix

Additional reading:
Featured section with more details on the Bulletproof Diet and the PKDproof program: https://www.facebook.com/groups/reversingpkd/announcements
Reversing PKD Book: https://reversingpkd.com/booklinks
Fiber lowers blood endotoxin after meals: https://diabetesjournals.org/diabetes/article/67/Supplement_1/776-P/59642/Effect-of-Fiber-Intake-on-Glycemia-Insulin
My “More Keto Is Not Better” article: https://www.facebook.com/groups/610558479091161/permalink/1554865504660449/
Lipid Rafts: https://pubmed.ncbi.nlm.nih.gov/32390462/