Q & A

Q & A

This page as an open thread for reader questions, especially questions about personal health concerns.

I am putting this page up as a way to share knowledge — my knowledge with questioners, but also so that others with similar concerns can read the conversation, and readers with relevant knowledge can chip in with their own thoughts.

Please keep in mind that I can’t research questions in any depth, so my answers should be considered tentative, incomplete, and subject to later correction. Also, I am not a doctor, and nothing I say should be construed as a substitute for medical diagnosis and treatment. I am only sharing opinions about disease origins and general therapeutic strategies which may or may not be applicable in any given case.

To get the page started, I’ll put up a few questions from recent emails. Here is an index by disease, with clickable links:

And here are my answers.

Chronic Lymphocytic Leukemia (CLL)


Been following your work on the PHD before the publication of the book and commented on my CLL and the usefulness of Vitamin D once on your blog and you responded to keep an eye on my Vitamin K intake, which I do now.. Am fortunate in a way to have my form of CLL as it indolent which gives me the opportunity to experiment without the pressure of undergoing conventional treatment. The PHD, I think, is helpful in this regard.

Wonder if you could point anything out to me that may be useful. Anything at all. And I will be happy to share with you my results.

Surely you know of the helpfulness of green tea with CLL. You may not be familiar with research that points out that those with low levels of Vitamin D need treatment for CLL far sooner than those with elevated levels.

Feel strongly that your version of a ketogenic diet would be helpful but also feel I need some direction in this area. Do you have any suggestions?

Warmest Regards,


Hi A,

I remember your comment, thanks for writing back. I’m glad you’re enjoying our diet and wish you the best.

Thanks for the tips about green tea and vitamin D. Neither one surprises me.

Most likely CLL is caused by a viral infection. So enhancing viral immunity is probably a good idea. Good strategies may include: (1) low-protein dieting, which inhibits viral reproduction and can promote autophagy; (2) maintaining high vitamin D levels; and (3) intermittent fasting, which promotes autophagy.

Some food compounds have been reported to have antiviral effects. An example is green tea catechins, eg http://pmid.us/16137775, http://pmid.us/18313149, and http://pmid.us/18363746, and this could be why green tea is helpful against cancers, http://pmid.us/21595018, which are usually viral in origin.

I might search Pubmed for herbs and spices with antiviral effects, and use them abundantly in cooking, along with antiviral foods. Turmeric / curcumin is a good choice, this needs to be taken with black pepper to enter the body. See http://pmid.us/21299124, http://pmid.us/20434445, http://pmid.us/20026048.

Coconut oil / lauric acid also has some antiviral properties, so inducing ketosis with coconut oil could benefit you even aside from the ketosis. You could also try monolaurin supplements which may enter the body better and which some people have reported to help viral infections.

You might also try HDL-raising tactics as discussed in this series: HDL and Immunity, April 12; HDL: Higher is Good, But is Highest Best?, April 14; How to Raise HDL, April 20.

Another possible tactic is high-dose riboflavin with UV exposure on the eyes. This requires going outdoors at midday and not wearing glasses or contact lenses. Riboflavin+UV is toxic to blood-borne viruses, and the retina is a location where UV can reach circulating blood cells. Sun exposure will also help you optimize vitamin D.

That’s a few ideas, at some point I’ll do some research to come up with more and do a blog post. Do keep me posted on your results!

Best, Paul

Bloating, acid reflux, anxiety, depression, hypoglycemia, hypothyroidism, fatigue

Just came upon your website and had a question for you. I have had some health concerns for the last four years, bloating, acid reflux, anxiety, depression, hypoglycemia symptoms, female complaints (I am in my forties), thyroid antibodies at 333, weight gain around my middle and too tired to work out like I once did. I used to be fikiiled with energy and great health no depression or anxiety. My doctor thinks these symtoms are all from peri-menopause and wants to treat me with Zoloft.

Needless to say I have tried to avoid the Zoloft. I have tired every avenue out there to cure myself. Most recently the Primal type diet. When I eat no grains or dairy I get horrible hypoglycemia symptoms and don’t feel great like everyone else on a low carb diet. I feel weak and more anxious. Do you think your diet would be easier for me with the addition of rice and potatoes?


Hi G,

Yes, I do think our diet will be better for you. You should eat enough starches to avoid hypoglycemia.

The key thing for you is treating the infections which are consuming so much glucose and making you glucose-deficient if you don’t eat enough carbs. Whatever pathogen(s) this is, it seems to have infected your gut and caused the various gut problems; circulating pathogen-derived toxins and immune cytokines are probably responsible for the anxiety and depression. Hashimoto’s hypothyroidism may be either due to circulating toxins or a thyroid infection.

I would suspect some kind of protozoal or parasitic infection due to the hypoglycemia, but what I really recommend is getting your doctor to have a stool sample analyzed for pathogens. Metametrix has a good test. Once you know what pathogen to treat, and get on a better diet like ours, you should improve quickly.


I am writing on behalf of my mother … We live in Dhaka Bangladesh …

Before her illness, my mom was 105 lbs, 5 feet tall and always 10ft tall in spirit…. When she was diagnosed with Lupus at the age of 30, we were all overwhelmed and out of our depths. My beautiful, athletic mother was in a wheelchair and given 6 months to live….

The doctors has advised her to eat literally nothing, minimum protein (1 small piece of chicken/fish, limited to 20g protein per day), only 2-3 types of vegetable and 2-3 fruits and of course lots of carbs to apparently compensate for her failing KIDNEY and LUPUS. She is on tons of medication, no food except the wrong foods (carbs) and in chronic pain. She currently weighs 139 lbs.

Please advise. — S

Hi S,

I believe lupus is a catch-all diagnosis for a variety of conditions which are probably caused by undiagnosed infections. In the US the infections are usually bacterial. I’ve known several people with diagnosed lupus who were cured by antibiotic treatments – in one case the problem was Lyme disease (Borrelia). I have no idea what the likely pathogens would be in Bangladesh. If she does better on low carb and coconut oil, that indicates bacteria; if she does better on high-carb, that indicates protozoa.

A healthy diet is very important. It is very bad advice to “eat literally nothing,” it is essential to be well nourished. Protein is necessary for healing and immune function, and 20 g/day is too little. Fasting is good, but it should be intermittent – not starvation! She needs healthy fats, more protein, and lots of micronutrients. Eggs, shellfish, seafood, bone broth soups, vegetable soups, and fermented vegetables may all be helpful. Coconut milk is probably good for her. You should basically follow the program in our book.

I would try to put her on a good diet, give her a little time for kidneys and other tissues to heal, and then try antimicrobial medicines. Usually, if they’re not working, then you don’t notice an effect. Any strong effect, good or bad, means they are working. Bad effects mean that pathogens are dying and releasing a lot of toxins as they disintegrate. If this occurs, detox aids (salt, water, and one of cholestyramine/charcoal/bentonite clay; also glutathione supports and vitamin C) will help.

Please stay in touch and let me know how things go.

Best, Paul


Jersie wrote:

I’ve suffered from depression for decades. A few months ago, I decided to try the Dr. Kruse protocol for jumpstarting leptin sensitivity and 2 interesting things happened.

When I went very low carb – below 50 gm -. I had half-day periods where the depression suddenly lifted (something that has rarely happened otherwise). However, I also suffered from darker than normal periods.

I stopped the Dr. Kruse protocol after 6 weeks, and went back to regular paleo (approx. 200 – 300 gm. Carb/day). I’m now generally more depressed than usual, without the good periods.

These changes seem to indicate that I can have an influence on my depression with diet, but not sure what diet to try. Thoughts?

Hi Jersie,

I think your experience on very low carb is diagnostically telling.

I would interpret it this way:

  1. Your depression is caused by an interferon-gamma mediated immune response in the brain, probably caused by a viral or bacterial infection. This leads to tryptophan being directed away from serotonin and toward the kynurenine pathway. So you have a serotonin deficiency and kynurenine excess.
  2. A ketogenic diet is both therapeutic (promotes immunity against bacterial and viral infections) and mood-improving (clears kynurenine).
  3. However, you are at risk for hypoglycemia in the brain (especially if the infection is bacterial) and hypoglycemia causes irritability/anxiety and can aggravate depression.

So the very low-carb diet had mixed effects (ketosis, hypoglycemia).

What I would do is follow our ketogenic diet advice. Eat at least 50 g/day carbs from starches to get sufficient glucose, plus sufficient protein to reach 600 calories/day protein+carb, but add in large amounts of MCT oil or coconut oil. Also, do intermittent fasting – eat all the carbs within an 8-hour window; eat at least half the MCT oil in the 16-hour fasting window.

Once on a good diet, I might experiment with antibiotics to see if they relieve symptoms.

Please let me know how things go.

Leave a comment ?


  1. Hi Paul,

    Reaching out for thoughts as you book previously helped me “solve” my digestion issues. For the last 6 months I’ve been experiencing ENT related issues and doctors I’ve seen so far only blame stress, which doesn’t help much.
    It started in Sept with stuffy nose/difficulty to breath with nose, although there was nothing inside. Then some weeks later I spit some blood that was in my mouth. This happened several time so it got me really anxious and went to the doctor. I did general blood test, radio of lumbs and sinuses, everything was ok. Still it generated a lot of stress and other issues started to appear: dry mouth, feeling of having something stuck in the throat (left side only), strange inflammation on tongue spreading around… I went to an ENT specialist that looked everywhere with the camera and said there was nothing wrong, he just told me to put salted water in the nose and eat candies to foster salivation. Went to the dentist that said the blood was coming from gums and indeed after descaling the blood in mouth almost completely disappeared. Then I started to have nasopharyngitys that wouldn’t heal, with blood in nose and even blood when I coughed once, something that never happened to me before. Again doctors said there was nothing to worry about and advise me to try and fix my stress issues instead. The doctor gave me rabeprazol in case inflamation was caused by acid reflux. It did not help at all but generated bloating, muscle tensions, eye and muscle shaking… (not sure it’s linked but started at the same time). Since then I did sophrology, hypnosis, went to the psy, take magnesium supplements. Just came back from 3 week holidays where I was not stressed at all, yet still the same throat issues when swallowing and the impression that it spreads with muscular problems in neck/shoulders/chest/jaw as well – everything only on the left side. To give you some background I’m 34 and lean, used to do a lot of allergies when I was a child, had IBS-like symptoms for almost 15yrs that I fixed around 3yrs ago with better eating (thanks to your book) and hypnopraxy, started boxing again in September (not sure it’s related but timing is the same), also had once muscle tensions problem in the neck/shoulder/head that could be fixed only with diazepam. Doctors just say it’s linked to stress whereas I believe there is something wrong somewhere, and stress might amplify symptoms and create toher ones (e.g. muscle tension). Any hint or thoughts would be much appreciated on where to look for and what version of PHD diet you would recommend to tackle this… thanks so much

    • Hi Julien,

      I’m not a doctor and acute issues like this really need to be diagnosed by a good doctor. So I would keep pressing on them.

      I would avoid boxing, as injury can promote infection, and also I’d worry about salt water in the nose. Salt water in the mouth is good as this normalizes pH and can help get rid of oral infections, but nasal washes may be risky based on the neti pot experience, https://www.cbsnews.com/news/is-it-safe-to-rinse-your-sinuses-with-a-neti-pot/.

      Here are some general principles that may help: Vitamin A and vitamin D are crucial for mucosal immunity, thus for sinus, earway, throat, lungs, and mouth immunity. Be sure to optimize these, take extra until you notice a difference, it’s probably not a coincidence that this came up in the winter. Supplement vitamin C at least 5 g/day, N-acetylcysteine, glycine. Optimize zinc and copper. Circadian rhythm entrainment, intermittent fasting.

      Best, Paul

      • Paul, thanks so much for taking the time to answer. I’ve book an appointment with another ENT specialist to dig further.

        Thanks a lot for general principles, will start ASAP and update if any improvement. 5g vitamin C does seem a lot compared to recommendations we usually get in France. Do you think I should continue magnesium intake? (was taking a supplement with magnesium/vitamins B/taurine but can switch to magnesium only).

        Thanks again for all your work and responsiveness.


        • I think magnesium daily and B vitamins at most weekly is better.

        • May not be related, but when I have dairy, I can’t breathe through my nose. Doesn’t help with all the other complications though.

          • Hi Helena, thanks. Don’t eat much dairy except old cheese, but will try to se if there is a link

        • Julien, in addition to Paul’s recommendations – you could try the following:

          You mentioned a history of allergies, IBS and now ENT issues. This could mean a defective mucosal layer as one of the factors leading to inflammation.

          For a few weeks try to eliminate eggs, organ meats, aged cheese and fermented vegetables BUT supplement with phosphatidylcholine. PC is the major phospholipid present in mucus. It creates a protective hydrophobic surface which is essential for mucosal defense. The richest food sources of choline are eggs and organ meats but ironically these are also most likely to cause reactions.

    • Nothing stresses me like being told, “It’s just stress.” Bless you, I hope you find the right doctor or other health practitioner. I have been playing with my own doses of magnesium for continued muscle tension and have found that I need more than “recommended,” and that I need the dosage spread out through the day, and I’m taking different varieties.

      And I put frankincense up my nose when inflamed. Hello, sorry for the TMI, but it helps. And frankincense topically is good for many other things I haven’t been able to heal.

      And I’ve read that kimchi has a particularly great effect on sinus health, so maybe you could try it. Can’t hurt.

      And the use of vitamin C at especially custom doses is a good thing to read/learn about. Listen to Dr. Robert Cathcart on youtube, for example. May you get the healing you need!

      • Hey St, thanks a lot for the input – will have a look to all of this. Just started magnesium glycinate, let’s see if that helps

    • Julien,
      The link Paul provided about neti pots (or other containers that one can use to do a salt water rinse/douche of the nasal passages) says that, “when used and cleaned properly, neti pots are usually safe and effective”.
      As long as you keep the container clean, prepare the rinsing liquid appropriately, use “pure” salt as an add-in (and use the proper amount of salt to water that will create a gentle saline solution), and so forth, rinsing the nasal passages with salt water can be a beneficial, healthy, restorative procedure.
      About 18 years ago, after I had experienced 20 years of year-round airborne allergies, and had used prescription allergy medicine (with unpleasant side effects) for 15 of those years, allergy medicine was no longer effective and my doctor had nothing else to offer me, so in desperation I tried doing nasal douching/rinsing with salt water, and it helped me tremendously! Indeed, after 6 months of doing the nasal rinsing twice a day, I didn’t have any allergy symptoms at all, and I have now gone 16 years without taking any prescription or over-the-counter allergy medicine (except for about 6 days in the entire 16 years, when I would be travelling and have an allergic reaction to something unusual).
      That was a near-miraculous change for me!
      After those 6 months, I stopped doing the nasal rinsing on a daily basis, but I would do it occasionally, and it always felt great. There was no doubt that it was soothing and healing for me — the benefits were obvious.
      I would still be doing it once in a while, but I developed an unusual and unrelated medical issue (which is not at all connected to nasal rinsing or to airborne allergies) and my surgeon told me that it would be safer for me not to do nasal rinsing with my condition.
      Nasal rinsing, or “jala neti” (and thus the name “neti pot”), has been a health technique in India for thousands of years, and millions of people do it, so I don’t think it is to be feared.
      Just research the practice first, keep everything clean, use proper ratios of salt and boiled water, and give it time to work.

  2. Paul,

    I have a nontoxic multinodular goiter. What would be your recommendation on healing this?


  3. Hi Paul,

    I was on ketogenic diet for about 18 months, and suddenly became very ill. I discovered an article on Mark’s Daily apple that quoted you on ketogenic diets and fungal infections. I have a history of both candida and mycoplasma. Wihin days of implementing the PHD and adding safe starches, I felt immediate relief (no more gas, bloating, day-long bouts of diarrhea, etc.) but after a few weeks on PHD, the symptoms have returned — I don’t eat any inflammatory foods (gluten, dairy, soy, etc.) Any insight as to why I got better, and now worse? I am beside myself — it seems as though everything I ate makes me sick.

    • Melancholy Aeon

      Hi Adrienne!

      So frustrating, right? Have you been tested for SIBO? This could explain your experience. Best wishes!

  4. Hi Paul,

    Manganese! My plasma manganese level has been pretty much drifting down since 2015 – last test below ref range. Not sure why. I have supplemented wisely over this time but not manganese specifically but periodically as part of a multi to see what happened. Other minerals low also. (Zinc mostly) I eat pretty much as your book states with some concessions. I guess I am asking in the case of low manganese (or any other low plasma readings) is it wise to just target they mineral?

  5. Hi Paul
    What do you think of organic sulfur / MSM powder as supplement ?

    Could it cause weight gain as reverse effect ?
    And if , why ?

    Thanks for your answer

    • Better to get sulfur from food, I think garlic and onion are good sources. It’s important to good health indeed.

      I think there is nothing wrong in sulfur supplements themselves and may be helpful in some conditions, but if I remember correctly, bacteria uses it too so that it may feed up oportunistic bacteria in our gut, so better to have caution.

      If I’m wrong please someone corrects me.

  6. Hi Paul,

    I’ve been doing some general research into the endocannabinoid system and various effects of phyto cannabinoids. I know because cannabis is still a schedule 1 drug it’s hard to compile good research on it, but I was wondering what role you saw the endocannabinoid system playing in general health and what you thought cannabis’ potential might be as a way to regulate the endocannabinoid system.


    Nick T

  7. Paul,
    I found out recently that I’m deficient in both linoleic and gamma linolenic acid. Is this something to be concerned about? If so, what would you recommend as the best way to correct this? Thank you.

    • Hi Mary, It’s hard to be deficient in these. What’s the evidence? Do you have eczema? Best, Paul

      • I haven’t been diagnosed with eczema, but my skin is dry. I especially have trouble with the skin on my hands being dry and cracked. I had a fatty acids profile done (plasma) – which showed that I’m deficient in these two fatty acids (and very high in EPA and DHA). Thank you.

  8. Hi Paul,

    Is Choline in eggs in phosphatidylcholine form better and more bioavailable than Choline Bitartrate supplement? Or there is not much difference?


  9. Hi Paul,

    Is it not a good idea to take Zinc and Copper at the same time? I heard they will compete for absorption, does this prevent proper absorption of both? Should I take them at different times? Or it is not a big deal and it’s okay to take them together?


    • John,
      I had the same question a few years ago, and as far as I could tell when I was trying to find an answer, it is okay to take them together if they are both in modest amounts and at a recommended ratio (like 1:10 or 1:15 of copper:zinc).
      They do appear together in most multi-vitamin/multi-mineral supplements, of course, and there are several standalone zinc supplements which include a bit of copper in them.
      Therefore, I suspect it’s “not a big deal” to take modest amounts of both at the same time, if that’s what you’d like to do.
      [I actually discovered that taking any kind of supplemental copper, even a fraction of a 1 mg tablet, was giving me unwanted side effects in my nails, so I take a modest level of zinc (about 11 mg once or twice a day) but no copper these days.]

  10. hi Paul,

    I just got diagnosed with Leaky gut, Candida, disbiosis and celiac disease. I have severe problems with joint pain, migraines, digestive issues and so on. I’ve been given Nystatin, enzymes, acacia powder, liponic acid, butyrat and probiotics.

    I’ve been thinking about doing your special diet for healing the gut and exclude dairy, etc, but would it be enough just to do PHD? (tests showed no reaction to dairy)

    Is there anything I need to consider with the Candida? low sugar? How low? is there anything else I should think of? I want to make the most of the Nystatin treatment and get rid of the Candida.

    I would be so thankful for your input!

    kind regards

    • Hi Leni,

      Yes, start with PHD. That will fix many issues and clarify what remains. There’s probably no need to exclude dairy.

      With Candida, keys are optimization of vitamin A and D, getting 3 egg yolks per day and 2 tbsp vinegar, getting dietary acids like vitamin C, vinegar, and lemon juice, intermittent fasting, circadian rhythm entrainment, adequate carbs along PHD lines, bile acid supports e.g. taurine, glycine, N-acetylcysteine, vitamin C, and egg yolks. Eat a balanced diet, don’t try to go super low in sugar, do eat fruit but don’t eat processed foods with added sugar.

      Best, Paul

      • thank you so much for your reply! I’ll follow phd and the additional advice. I hope to check in again in a while with some good updates. 🙂

        • the Nystatin is making me very sick, is that common? My joint pain in through the roof and I feel very ill. is that a Candida die off or maybe a reaction to the medicine?

          • I don’t know, I have no experience with Nystatin. You should speak to the doctor who prescribed it.

            Best, Paul

          • ok I will. I read somewhere that you had Candida, how did you get rid if it?

          • Hi Leni,

            Diet and lifestyle. Drugs like fluconazole and nystatin didn’t help me, or what help they gave was balanced by negative effects. PHD and our lifestyle advice (intermittent fasting, circadian rhythm entrainment), with some points of emphasis nutritionally: vitamins A, D, and C, iodine, vegetables, 3 egg yolks per day, N-acetylcysteine, extracellular matrix, healthy acids like vinegar, zinc and copper, maybe chromium which is antifungal but usually not necessary. Ultimately your immune system plus beneficial bacteria are what beats fungal infections.

            Best, Paul

          • thank you again! so I can just follow the advice regarding the dose of the supplements and so on from your site? is n-acetylcysteine (and taurine, glycine) safe to take when having gastritis/inflammation? If I can’t make bone broth is gelatin ok as a substitute? … and where to get the vitamin A from? I have vitamin C and D already. what do you think of digestive enzymes? thank you again for your help, you have no idea how much it means.

  11. Paul, I just read something about vitamin C supplementation and would like your take on it. “ CAUTION: Always take Vitamin C with no fat in your stomach: studies have shown that Vitamin C supplements increase nitrosamine (a carcinogen) levels in the body with even 10% fat in the stomach. “


  12. Hi Paul,

    I was recently diagnosed with diabetes, and my doctor put me on Metformin, and also on another drug called Jardiance, which makes you pee out glucose (I read it makes you pee out 200-300 calories a day).

    I am now starting to adopt the PHD diet, but I was wondering the right amount on carb consumption. You recommend diabetics to limit carbs to 400 calories a day. But since I’m taking this drug that makes me pee out glucose, is it okay for me to eat more than 400 calories of carbs a day? Or maybe the question should be Should I eat more than 400 calories of carbs a day in this case to avoid glucose deficiency? Or would you recommend not taking these drugs at all?

    Thank you

    • Hi John,

      I think 600 carb calories a day would probably be more suitable. That should be good even without the drug, so I’d aim for it.

      I’m sorry, I can’t give advice about drugs.

      Best, Paul

  13. Hi Paul,

    I live in the UK and am about to start this diet with my husband – we’re excited about it! The only thing is trying to work out the carb quantities. Obviously I know the weights you mention – 450g of safe starches, but are they of cooked or non cooked foods? I saw on one of your pages that you tend to have 150g (400cal) of cooked white rice twice a day …is the smaller weight because it’s cooked? I guess my question also applies to animal foods too – cooked / non? For eggs – shell / no shell?

    Also I’m a short, petite female with a sedentary job and my husband is a tall, well-built male with a physical job. Is there a range we can work to with all the different quantities of protein / carbs etc, so that we both are eating the right quantity for our builds?

    Many thanks!


    • Hi Clare,

      Generally, you should cook starches like potatoes gently so that they do not lose moisture (and therefore weight). For starches that are bought dehydrated and gain water in cooking, like rice, use the cooked weight.

      So the answer would be, always use the larger of the two weights; and try to cook so that the final weight is close to the largest weight. Having water in food is good for digestion.

      Just keep the PHD proportions and let your appetite dictate quantity. You don’t need to weigh or manage food for more than one or two days, but it can be helpful to do so as it is educational about how the different foods compare and what good proportions are. After that, just eyeball things. Volume is generally closely proportional to weight, so go by size to get proportions right, then appetite for quantity.

      Best, Paul

      • Paul, firstly can I say that I’m so impressed that you have come back so quickly – fantastic as you must be so busy.

        Think I’m still a bit confused though ! ‘the larger of the two weights’….would you mind giving me an example of you mean?

        Perhaps I’m obsessing with weights of stuff a bit too much. Just want to start things right – as you say, after that I can eyeball it / adjust to appetite.

        With animal produce – roughly 3 eggs and 340g of (raw) meat per day?

        Many thanks again!


        • ClareB,
          An example of what Paul meant by “use the larger of the two weights”/”try to cook so that the final weight is close to the largest weight” is this:
          Let’s say you are looking to have 100 grams of potato at dinner.
          You could measure out 100 grams of raw potato and then cook it. Depending on the cooking method, the final result of that 100-gram portion of raw potato might be the same, a bit more, or a bit less than 100 grams.
          If your cooked potato portion weighs more than it did raw, the cooked food is the “larger of the two weights” and you should measure out 100 grams of the cooked food to reach your target for that item. If your cooked potato portion weighs less after cooking than it did raw, the raw food was the “larger of the two weights” and you should eat the pre-cooked quantity that had weighed in at 100 grams before you cooked it.
          Another way to measure your hypothetical 100 gram portion would be to cook your potatoes (in whatever manner) and then measure out 100 grams of the cooked food.
          If you prepared the potatoes in a way that reduced a lot of their innate moisture, to make 100 grams of cooked potato would require, perhaps, 120 grams of raw potato at the start.
          If you want to be consistent with your intake of individual foods across cooking styles and recipes, it’s probably more accurate to measure most foods before cooking them. [However, with something like rice, which is purchased dehydrated and must be reconstituted with liquid before it can be eaten, Paul says that the weight of rice for PHD-proportion purposes should be measured after it is cooked.]
          Then, Paul points out that keeping foodstuffs moist during cooking (e.g., by boiling and steaming) will result in their weight staying more stable than using cooking methods which might remove innate moisture from them (such as frying or roasting). So trying “to cook so that the final weight is close to the largest weight” means to choose a cooking method that results in 100-grams-worth of raw potato ending up working out to be about 100-grams-worth of cooked potato, or close to it.

  14. …to add to the comment before for clarity. I am talking about the weight quantities of each food when raw / cooked…not whether to eat it cooked or non-cooked ha ha!


  15. I am wondering what your take is on SIBO. The starches in this diet seem like they could be bad for someone with a history of SIBO. Also, people with SIBO are advised to avoid or minimize dairy.

    • Most important for SIBO is vitamins A and D, egg yolks, vinegar, vitamin C, intermittent fasting, circadian rhythm entrainment, and a natural whole foods diet (avoid processed foods made with starch sugar oil). Natural food starches are beneficial. Dairy is fine unless there is autoimmunity.

      • In the book, it does not say exactly how to add vinegar to a potato (usually its added when boiling things). Or, do you mean vinegar should be added when we boil the potatoes or rice? Does type of vinegar matter?

        • Generally, the best time is to mix it with food or a beverage. For example, make a salad dressing with vinegar and olive oil. Sprinkle vinegar and butter on potatoes as you serve them.

  16. Also, for constipation, do you have any supplement recs other than magnesium citrate, which is irritating to my stomach?

    • AG, for most of my life (from early childhood onward) I have been constipated, no matter what I did or tried.
      The typical medical and lay advice for constipation mainly does not work for me. Fiber actually makes things worse.
      Happily, two years ago, I found something that made a huge difference — instead of “going to the bathroom” about 6 times a month as I used to, I now go about once a day.
      It is a probiotic strain that has different brand names in different countries, but is called “Bifidobacterium 35624”. (I won’t list the US or UK brand name here because an earlier post of mine on this site – about a different topic – didn’t show up when I posted it, and I presume it went to the spam filter because I had mentioned 2 brand names of supplements in it.)
      This probiotic strain is patented and is a bit expensive, but there are often sales and coupons for it.
      It is apparently the “number one gastroenterologist recommended probiotic brand” (I’m looking at my box of it while I type this comment, ha ha.)
      It’s especially good for constipation.
      At this point, after taking it for 2 years, I can economize by taking 1 capsule of it every other day instead of every day, and still stay “regular”. On the alternate days, I take a probiotic “pearl” type of pill by a different company that has 5 well-researched strains in it and is pretty good (but it isn’t enough on its own to keep me regular).
      Also, I stopped eating most grains about 18 months ago (because I was having joint pain, bloating, gas, acid reflux, etc., and unfortunately different food elimination experiments showed me that a big factor in my physical discomfort was (most types of) grains – even certified-gluten-free oats, sadly) and I think avoiding those has also helped my bowels to be more regular and for the bloating and reflux to subside.
      However, if I stop taking the “magic” Bifidobacterium 35624 probiotic for a week or two, my bowel movement frequency goes right down again, so I know that my current regularity is mainly due to the probiotic, and it’s something I’ll have to keep taking in the medium term (if not the long term) if I want to be as regular as I am these days.
      …One ongoing concern is that my movements still consist of little lumps that are on the low side of the Bristol Stool Scale, so I need to work more on that part of my elimination.
      It was a MAJOR improvement, though, for me to go relatively quickly (within a couple of weeks of first taking the Bifidobacterium 35624 daily) from pooing-once-every-5-days-on-average to pooing-once-a-day-on-average!
      I would recommend giving it a trial. You can buy a 14-day box for between $7 and $17 (US $), depending on the store (online retailers tend to be cheaper for it).

  17. Hi Paul,

    I want to thank you and Shou-Ching for everything you are doing. I am very happy to have found your work.

    I have been diagnosed with a C. Difficile infection and am wondering if you recommend I take the Metronidazole the doctor has prescribed or if there is an alternative method of eradicating the C. Diff (or if maybe eradication is not even necessary).


    • Hi Jackson,

      Antibiotics can be beneficial, whether to try them or not is a medical judgment that we can’t comment on, though the worse your symptoms the more likely the antibiotics are to be helpful. Regardless of your decision there, you need to take steps to improve immunity and support the immune system’s reshaping of the gut microbiome to replace the C difficile with beneficial bacteria. That requires a natural whole foods diet, vitamin A and D optimization, intermittent fasting, circadian rhythm entrainment, nutrients for extracellular matrix and bile, vitamin C and vinegar and egg yolks, and other PHD steps.

      Best, Paul

      • Thank you so much for the response Paul!

        I did decide to take the antibiotics.

        I understand that you are not a medical doctor, but I’m wondering if you may be able to point me in the right direction regarding a couple of other aspects of my health situation.

        I have been dealing with low iron and anemia for almost three years. Both have not responded at all to intravenous iron injections or oral iron supplementation. I have had 4 colonoscopies and 3 endoscopies looking for internal bleeding and signs of chrohn’s disease and all of the 7 tests did not find either.

        I experience blood in my stool from time to time. It takes place in “episodes” that last a couple of days and then does not come back until the next “episode.”

        More recently I have had low Albumin on blood reports.

        I am wondering if these symptoms may be due to undereating. I experience a high level of anxiety on a daily basis and find it extremely hard to eat when stressed. I would estimate I have been eating roughly 2000 calories per day for the past couple of years on most days. There was a time in which I tracked my caloric intake so I feel confident in this estimation. Is this too little for me? I am a 23 year old male, 5′ 8″ and about 135 lbs. I don’t get a large amount of exercise. Is my level of bodyfat possibly too low and this is causing the anemia and low iron?

        Or, is there likely something else going on here like internal bleeding or an autoimmune condition? Could the C Difficile (If I have had it this whole time), have caused internal bleeding and blood in stool resulting in anemia?

        Is the low albumin maybe from not having much muscle mass (i have tried to put on muscle through strength training with little success, maybe because of my lack of calories?)? Or is that maybe from malnutrition?

        Is there anything you suggest I do other than implementing the PHD and eating Liver as recommended (in case my anemia is due to copper deficiency)?

        Thanks again!

        • Hi Jackson,

          Low iron can be brought about by copper deficiency, so make sure you get adequate copper. Ruminant livers (beef, lamb) are the best source. Chocolate and nuts are also good.

          Undereating can certainly contribute to malnutrition and many negative symptoms. However, 2000 calories should be adequate nutritionally if it is from natural whole foods and you eat a good mix including vegetables.

          It’s difficult to guess causes without a detailed look at medical labs and other information, but malnutrition and a gut infection are certainly good candidates for causes. Why don’t you try the first set of changes with the antibiotics and then report back on how things change, including lab values.

          Best, Paul

          • Hi Paul,

            That’s very helpful, thanks.

            The 2,000 calories I had been eating was from whole foods, but included things such as legumes, wheat, oats, etc and was lacking in some of the supplemental foods recommended on the PHD. It will be interesting to see how I respond to the dietary change.

            I will also definitely report back after the course of antibiotics.

            Do you recommend I take probiotics while taking the antibiotic? If yes, is there a specific brand or specific strains that you recommend?

          • Another question (sorry to bombard you haha!):

            I know that you are in the Boston area. I also live in Massachusetts. I was wondering if there are any medical doctors, functional medicine doctors, or naturopaths in Massachusetts that you can recommend? I did check your list of healers and didn’t see any in MA, but figured I would check to see if you may have come across someone since creating that page.

        • Jackson, I realize your post was many months ago, but coincidentally a family member of mine this week has been plagued with post-antibiotic diarrhea that is probably due to c. difficile (a stool sample was taken by the doctor, and we will know if it appears to be c. diff after we hear back about the results).
          For several years, she has been taking daily a good general probiotic, but this week I have researched whether there are any specific probiotic strains that have had success against c. difficile, and there are several that are mentioned in various Pubmed.gov medical articles: The main 2 strains that I found the most mentions of, in regards to having some success against c. difficile are:
          1. s. boulardi (a yeast) (I am not sure I spelled that correctly, but it’s close), which can be found in a US over-the-counter probiotic called Florastor
          2. another strain whose name completely slips my mind at the moment but which is the only strain in a US over-the-counter probiotic called Culturelle.
          They are not inexpensive at about $22 each for 20 (Florastor) and 30 pills (Culturelle). Florastor’s directions say to take up to 4 a day if you are trying to heal a gut issue, so the 20-pack is potentially only 5 days’ worth. However, c. diff can be a serious thing (my relative who has post-antibiotic diarrhea is elderly, which is a high-risk category for c. diff), so I bought both of those probiotics at the store and I am trying them out on her (along with following all the instructions I found online for how to treat post-antibiotic diarrhea that is possibly caused by c. diff, including at the CDC.gov site, Mayo Clinic site, Medscape, etc.)
          Check out Pubmed.gov and look up the studies on post-antibiotic diarrhea and probiotics. Not all of them are pro-probiotics, and apparently some major medical organizations do not yet accept that it’s appropriate and beneficial to take probiotics to treat c. diff (and other bacterial infections that cause post-antibiotic diarrhea), but other ones do say it’s beneficial and appropriate, and there are some studies that show a real benefit from those 2 strains (and some others).

          In terms of your low iron which has not responded to iron supplements, I also have low iron which does not respond to any types of iron supplement (my blood carries it around and starts to have too-high iron readings, but the iron doesn’t get carried into/utilized in the cells that need it). A number of doctors have told me there is no point to my taking iron supplements. Oddly, they didn’t have any explanation for me about why my body acts this way, or if there were anything else I could try, other than agreeing with me after I would ask them if this means that I should try to eat more red meat, in case my body can absorb the iron from it better (it doesn’t seem to, but I don’t really like meat generally, so even eating a modest amount daily takes effort.) After spending years trying to force my ferritin level higher to no avail, I came to a point where I wondered if perhaps my body has a mysterious reason for keeping its iron low — maybe it’s trying to protect me from something harmful that would flourish with more iron available to it.
          If you’ve even had transfusions though, that seems odd that those haven’t increased your iron.
          It sounds like 2000 calories should not be too low for your body and activity level, but maybe you have nutrient deficiencies you are unaware of which are preventing things from firing on all cylinders and building mass, muscle and energy for you.
          How are your B12 and folate? They are relevant to some types of anemia.
          Do you have any genetic mutations that stand out (maybe you can do the 23andme test – I learned lots of very interesting and practically-useful information when I did mine).
          Can you work on ameliorating your daily anxiety levels to encourage healthier/happier eating patterns for yourself? Have you spoken to a counselor about those concerns? That could well open up some pathways to healing and physical flourishing.
          How about ordering a week or two of high-quality, nutritionally-sound prepared/catered/mail-order-delivered/etc. meals (or going to a good spa/health resort for an all-inclusive vacation) so that you can experience several days’ worth of convenient, tasty, officially-compiled nutrition and get a feeling for the ingredient quantities and combinations that are health-bolstering and that you can aim to achieve in your everyday life.
          Maybe you could engage the services of a thoughtful holistic health clinician along the lines of Chris Kresser, who could work one-on-one with you and test the gamut, look at the whole picture, consider unconventional causes/treatments.

  18. Haemochromotosis Question

    Hi Paul, this may have come up before but I couldn’t find it on the blog.

    I have been on PhD diet for about 3 years, in recent blood tests I have very high iron.
    Ferritin 213 ug/L transferrin Transferrin Saturation 2.1 g/L.

    I’ve had further blood tests for Haemochromotosis and have one of the two associated genes but not the one that would normally mean a diagnosis of haemochromotosis.

    My general practitioner doctor has suggested it may be diet related.

    I don’t weigh my meals, just general follow PhD diet principles (I do eat a lot of red meat) and also take the following supplements:
    1 per day:
    Vit C Ascorbic Acid 500mg bioflavonoids 75mg
    Pantothenic Adic 500mg Calcium Pantothenate 45mg
    Boron 3mg (Calcium Borogluconate)

    2 x per day
    Magnesium Citrate 135mg

    1 x per week
    Zinc icolinate 30mg

    I would really appreciate your feedback/opinion on this, thanks Ben in Tasmania, Australia

    • Hi Ben,

      I would say the key thing would be to donate blood regularly — i.e. once every two months.

      I find my ferritin is usually about 50 after blood donation and 120-150 before. Oscillating between 50 and 150 is a healthful range.

      It’s hard for men and postmenopausal women to optimize iron without blood donation. In our evolutionary past, bleeding was probably much more common than it is today, whether from injuries or intestinal parasites. Parasites would also reduce iron absorption.

      I wouldn’t be surprised to see a ferritin of 213 in someone who doesn’t donate blood.

      Best, Paul

      • Great, thanks Paul. I’ll sign up to donate blood asap. Another question, if donating blood reduces ferritin, is there a reduction of anything else as a consequence? Is there anything else that needs to be reboosted after donation?

        thanks again

  19. Great, thanks for getting back to me Paul.

    I’ll sign up for blood donating asap.

    by the way, if ferritin gets reduced is there anything else that does also? ie is there anything that needs re-boosting post blood donation?

    thanks again

  20. Hi Paul,
    I bought your book last week and been glued to it ever since. I suffer with constant constipation (this improved somewhat when i went gluten free but seems less effective now). I also have migraines, i have been able to link these to MSG, other preservatives and sulphites. I have been eating natural food for a while before starting to amend some things as i’m reading your book. However if i had a glass or two of wine, i would be 3 days in bed with migraine (organic wine is fine). Also i made the bone stock and the following day woke up with a (somewhat milder) migraine which lasted 2 days. I wondered if this could be due to the process extracting gelatine, which i have also thought might be a trigger before. I just wondered what your thoughts were and any tips for either the constipation or migraine would be appreciated. Thank you, Liz

    • Hi Liz,

      Welcome! You can find some advice for constipation at http://perfecthealthdiet.com/2011/04/causes-and-cures-for-constipation/ and a series of posts on migraines at http://perfecthealthdiet.com/category/disease/migraines-headaches/.

      It sounds like your migraines are triggered by amines, such as histamine or tyramine. Amino acids degrade into amines, so any old or overcooked meat will have high levels of amines, also many fermented foods such as wine or sauerkraut.

      You can improve amine clearance with some supplements, notably egg yolks (for choline/phospholipids), copper and zinc, molybdenum, vitamin C, and glutathione/N-acetylcysteine.

      You can also greatly reduce amine quantities in bone stock by careful preparation. Do a soak and then a flash boil of the bones, discarding the water, and then boil for a short time only (e.g. 3 hours) to make the stock.

      If that doesn’t work, you may need to avoid long-cooked and fermented foods until you handle them better.

      Best, Paul

  21. Hi Paul,

    Is there any reason that Bone Meal would not be an adequate substitute for Bone Broth as a supplemental food if making bone broth is incompatible with my schedule and lifestyle?


    • Hi Jackson,

      Bone is essentially a web of extracellular matrix, mineralized mostly with calcium phosphate.

      Since calcium phosphate has almost zero solubility in water — see https://en.wikipedia.org/wiki/Solubility_table — while collagen and other extracellular matrix components readily hydrolyze to become water-soluble, the process of making broth basically extracts almost all the extracellular matrix from the bone, while leaving almost all the calcium phosphate behind.

      (As an aside, the process of making broth also extracts a meaningful amount of certain trace minerals that accumulate in bone, such as fluoride — a couple milligrams of fluoride is biologically meaningful, while a couple milligrams of calcium is not.)

      This means bone and bone broth have completely different nutrient compositions: If you eat bone directly, you will overdose on calcium and phosphorus long before you get a meaningful amount of extracellular matrix components. If you drink broth, you will overdose on extracellular matrix components long before you get a meaningful amount of calcium and phosphorus.


      • Hi Eric,

        Thanks for the response! That makes sense.

        Would a way to remedy this without actually making homemade bone broth be to supplement bone meal for the calcium and phosphorous and to also take a collagen supplement? Are there other extracellular matrix components that are needed for optimal health, or is collagen the main one we are looking to get?

        Paul, do you care to comment on this?

        • Hi Jackson,

          I typically get on the order of 20 g / day of collagen and other extracellular matrix components from broth (on a dry weight basis). Can you find bulk powdered collagen? Because I imagine that taking on the order of 20 collagen pills per day would not be practical (you can’t fit much more than a gram into a pill).

          Another option is supplemental glycine; this is the most important amino acid in collagen. Note that 20 grams of collagen has about 5 grams of glycine, so this would reduce the volume of pills/powder substantially. Paul suggests this as a supplement for those who don’t eat sufficient extracellular matrix: see http://perfecthealthdiet.com/recommended-supplements/

          By the way, dairy has lots of calcium and phosphorus; if you eat dairy, then you probably don’t need the bone meal. Otherwise, it might be helpful.

          I don’t know much about what other extracellular matrix components are beneficial — my strategy is just to obtain them all by eating extracellular matrix directly (broth and/or tendons). Maybe Paul knows something more about this.


          • Eric,

            Thanks again for the input.

            I went back to read the section in the PHD book on Calcium, Collagen and Magnesium (I now realize I probably should have done this before asking my initial question). Anyways, in that section, Collagen supplementation is recommended against. Interesting though that Paul and Shou-Ching recommend Glycine on the supplement page for those who do not get sufficient extracellular matrix through the diet.

            Obviously the best plan is to eat bone broth to obtain all of these nutrients. But, do you think that a combination of Bone meal and Glycine could bring about somewhat similar benefits to actually eating the broth, or does it look like one would be lacking in a major way with this approach?

          • Hi Jackson,

            I’m not sure what fraction of the benefits you’d obtain from bone meal plus glycine. (I do, however, think that’s a better plan than just taking bone meal.)


    • Hi Jackson,

      [The website interface is behaving strangely… I’m not sure if I already submitted this comment or not. Apologies if this is a double post.]

      Bone is essentially a web of extracellular matrix, mineralized mostly with calcium phosphate.

      Since calcium phosphate has almost zero solubility in water — see https://en.wikipedia.org/wiki/Solubility_table — while collagen and other extracellular matrix components readily hydrolyze to become water-soluble, the process of making broth basically extracts almost all the extracellular matrix from the bone, while leaving almost all the calcium phosphate behind.

      (As an aside, the process of making broth also extracts a meaningful amount of certain trace minerals that accumulate in bone, such as fluoride — a couple milligrams of fluoride is biologically meaningful, while a couple milligrams of calcium is not.)

      This means bone and bone broth have completely different nutrient compositions: If you eat bone directly, you will overdose on calcium and phosphorus long before you get a meaningful amount of extracellular matrix components. If you drink broth, you will overdose on extracellular matrix components long before you get a meaningful amount of calcium and phosphorus.


    • Jackson,
      If you want the benefits of bone broth but your lifestyle won’t allow you to make homemade batches of it, why don’t you just buy pre-made bone broth and consume that, instead of trying to approximate the effects of broth with manufactured supplements that by their nature cannot do a thorough job of approximation?
      There are so many brands and types of packaged bone broth on the market now — you can order them online from big retail sites, from various health blogs/businesses, and directly from the broth manufacturers; you can find them locally in health food stores, supermarkets such as Whole Foods and Trader Joe’s (I would suspect – I don’t have those stores near where I live), and you can even find them in mainstream supermarkets across the country (which I can confirm because my local, middle-of-nowhere supermarkets have them).
      Packaged broth probably wouldn’t be as healthy as “fresh” broth, but it’s been very successful in the marketplace in the last few years, so it seems that many people are getting use out of it.
      The packaged broth sometimes has certain additives and flavorings in it which I personally try to avoid, so you have to read labels and find products whose ingredient lists you are okay with.

      If you live in a major metropolitan area, I expect that these days, bone broth (along with various other “paleo” foodstuffs, of course), is so popular that you can probably find freshly made bone broth for sale, such as at restaurants, delis, whatnot.
      By the way, it actually isn’t that time-consuming or fussy to make bone broth from poultry bones – especially if you have an electronic pressure cooker+slow cooker such as an Instant Pot — just program it and let it do its thing. But even if you are just doing it on the stove — you need to add some stuff and water to a pot, simmer it for some hours, strain it, and store it — it is not that complicated. You can do a bunch at once and freeze it in individual portions.
      My impression is that making broth from fresh beef bones is more a little more complicated and has more time-consuming steps to it, in order to make nice-tasting broth. I have only done it with poultry bones. But after the initial learning curve, beef broth is also probably not very difficult.

  22. Hi Paul,
    I’m new to your content and I found it very good. I am also very concerned right now and would love it if you could hep me. I’m an 18 year old male that has been having troubles with high blood pressure. I’m healthy looking and only wight 162 lbs and am about 5.8 feet tall. I sometimes eat bad but mostly have an alright diet, I just added more spring mix to my foods. My family loves red meat so that also is a trouble.
    My problems started last year when I had a bad panic attack on a marijuana edible that my friends gave me, after that I stopped touching weed, which I only did rarely. After that my mental health was horrible and had a few panic attacks throughout the moths, its been since November… A lot of things were in my mind about religion and paranoia and anxiety and the fear of me ruining my brain. I also vaped and hit a few cigarettes in my dumb days. The only unhealthy thing I do now is binge drinking about 2-3 times a month 😳 def quitting now for once and for all. I wasn’t allowed to donate blood because of low pressure so I got it checked and they said I had high… Got sent to the cardiologist and he told me to do some yoga and get less stressed because everything was OK, and I had to cut out bad cholesterol. I kind of was worried for a while but slowly started feeling better, now I went to a check up and they were concerned about my pressure again. I really dont want heart problems in the future or stroke risk. I feel hot flashes and dizziness every once in a while and my breathing pattern affects my heart beat.
    I decided to change my diet but I really don’t know what to do. I do cardio and weights at the gym about 5 or 4 times a week. This morning I checked my pressure and it was at 138 which was terrible. No idea if it has anything to do with anxiety or unhealthy lifestyle.
    I’d love it if you cold give me a piece of advice!
    Many blessings, 🙂

  23. Hi Jackson,

    [I apologize if I’ve already responded to your comment, perhaps even responded several times already… my computer is acting strangely.]

    Bone is essentially a web of extracellular matrix, mineralized mostly with calcium phosphate.

    Since calcium phosphate has almost zero solubility in water — see https://en.wikipedia.org/wiki/Solubility_table — while collagen and other extracellular matrix components readily hydrolyze to become water-soluble, the process of making broth basically extracts almost all the extracellular matrix from the bone, while leaving almost all the calcium phosphate behind.

    (As an aside, the process of making broth also extracts a meaningful amount of certain trace minerals that accumulate in bone, such as fluoride — a couple milligrams of fluoride is biologically meaningful, while a couple milligrams of calcium is not.)

    This means bone and bone broth have completely different nutrient compositions: If you eat bone directly, you will overdose on calcium and phosphorus long before you get a meaningful amount of extracellular matrix components. If you drink broth, you will overdose on extracellular matrix components long before you get a meaningful amount of calcium and phosphorus.


    • Hi Eric,

      This is off topic.

      if I remember correctly, in the past you wrote a comment somewhere in which you pointed out that some calculations regarding the goldilock amount of fiber in the book had some errors. I tried to look for it, but after much effort I couldn’t find it. I wonder if I dreamt it. I think you were the author of that comment. If possible, could you point out where the comment is? I’d like to read it if it still is somewhere.

      Thank you,
      Kind regards

  24. Hello Paul,

    Do the micronutrient recommendations change based on height/weight of a person? For example a 100 pound woman and a 200 pound man have the same magnesium requirements (200 mg/day)?

    Thank you

    • Hi John,

      Nutrient requirements typically scale like body weight to the 0.7 power.

      Best, Paul

      • Paul I’m sorry I could not understand what you meant by this, could you please clarify?

        • Hi John,

          Paul is saying that someone who weighs twice as much needs more nutrients, but not twice as much nutrients — rather, 2^0.7 = 1.62 times as much nutrients.

          Since his recommendations are for adults of average size (~150 pounds), he is saying that a 100 pound woman would need (100/150)^0.7 = 75% of the suggested dose, while a 200 pound man would need (200/150)^0.7 = 122% of the suggested dose.

          However, in the case of magnesium, I will point out that an average-sized adult weighs about 12 times as much as an average-sized 3 month old, and needs about 12 times as much magnesium —
          ~400 mg (c.f. Paul’s book) versus ~30 mg (c.f. the composition of human breast milk) — rather than only 12^0.7 = 5.7 times as much. (So it looks like the exponent of scaling for magnesium requirements in humans might be closer to 1.0 than 0.7.)


          • Hi Eric,

            Thank you for the explanation, now I understand.


          • I wonder if the average weight of US adults is actually more than 150 these days.
            I weigh 128 with a BMI of about 22, and according to a Wikipedia chart showing statistics on US women, for my age and my height, my weight is in in the lowest 8% of the population or something like that.
            In my city, in a state where people are generally very, very overweight, I’m certainly way in the left tail of the weight “bell curve” for women my age.
            …Though probably the “healthy”/target weight of the average adult American _should be_ 150.
            Maybe people should eat the nutrient requirements of their hypothetical “healthy” weight, rather than the nutrient requirements of their actual weight, I don’t know.
            I’ve spent a long time this month reading this blog, and when I read his above comment “scale like body weight to the 0.7 power”, that was the first time that I ever was reminded that Paul is an astrophysicist! It just goes to show how good he is at communicating with people from a wide variety of walks of life. 🙂
            Thanks for the breakdown of what that scaling would look like for a 100 pound or 200 pound person (as examples), Eric.
            Your last point about how the average-weight adult requirements for magnesium don’t scale up from the magnesium needs of the average-weight infant isn’t at odds with the general idea, as I understand it, because the general idea is to take what is required for the average-sized adult and scale that up or down by 0.7. Paul didn’t say to take what is required by 3-month-olds and scale that up by 0.7 to get the adult requirements. It’s only comparing the needs of grown-up adults of various sizes, not comparing the nutritional needs of babies to the nutritional needs of adults. Young children don’t have the same nutritional needs of adults (in the same ratios to weight and height), for many nutrients — at least, as I understand it. That is why the FDA issues different charts of recommended daily allowances (or whatever the term is that they use now, RDI or whatever) for different age bands, and also for males and for females.

  25. J Inglis-Jones

    Hi Paul – I’m a loyal phd follower for some years now – I have a bad back and am currently suffering from a bad bout of sciatica. 8 years ago I had a microdistectomy and am hoping to avoid that this time by giving my body the best chance to heal naturally. Are there any foods / supplements you would recommend to help my body deal with the problem. Thanks again for all your work.


    • Hi James,

      Most important for healing is extracellular matrix (which you can get from shellfish and from bones/joints/tendons made into stock) and vitamin C, plus minerals such as magnesium, and vitamin A, D, K2 optimization. Then circadian rhythm entrainment, intermittent fasting. Then providing the right physical/mechanical signals. For that I would try to find a nearby professional trained by the Posture Restoration Institute, https://www.posturalrestoration.com/.

      Best, Paul

    • I recommend looking into getting a prescription for gabapentin for the sciatica. It was a miracle drug for me when I had immobilizing pain from sciatica pursuant to a fractured pelvis (sciatica started 3 days after the fracture, after a long car ride home from hospital). Though the pain med I was already on for the fracture (percocet) was strong enough to eliminate that pain, it didn’t touch the sciatica. Thirty minutes after the first dose of gabapentin, the sciatic pain was gone. I continued taking gabapentin for several months, then tapered off.

      Good luck!


  26. Thanks so much for taking the time to answer


  27. Hi Paul

    I’m part way through reading your book and was wondering if you have had any experience with, specific advice for, or can point me in the direction of other resources dealing with psoriatic arthritis?

    I’ve had variable but mostly mild levels of psoriasis most of my adult life and have developed psoriatic arthritis in the past few years (I’m 63).

    My rheumatologist described it as an autoimmune form, similar to RA but not as progressive.

    Thank you

  28. Eric,

    I could not reply directly to your comment above. I just wanted to thank you for taking the time to respond to my question. It was very helpful!!


  29. Hi Paul,

    I’m wondering if your stance on fasting duration taken in the PHD book still remains.

    If I am understanding correctly, your stance was that fasts longer than 24 hours do no upregulate autophagy to a greater extent than a 16 to 24 hour fast. Do you still believe this?

    I am reading online about the benefits of 2-3 day or longer fasts, and if I am understanding it right, the consensus seems to be that longer fasts do actually provide more benefits in the way of autophagy than daily intermittent fasting. But, I am not sure of the credibility of some of the articles.


    • Hi Jackson,

      To be clear, longer fasts always upregulate autophagy more. But you have to do them less frequently — you can fast 16 hours every day, but you cannot fast 24 hours every day. So the question is, over the course of a year, which approach maximizes autophagy.

      Best, Paul

      • Thanks Paul, that makes sense.

        Another question: I came across some articles about a study done by Valter Longo in which a 3 day water fast “reset the immune system.” Are you familiar with this study?

        A quote from one article: “In both species, fasting lowered white blood cell counts, which in turn triggered the immune system to start producing new white blood cells.”

        Is this a desirable outcome? If yes, would fasting 16 hours daily likely produce the same result for the immune system over time?

        Thanks again!

  30. Paul, I hope this finds you well.
    I was delighted to discover the sanity, balance and science of the PHD after nearly 3 years as a raw vegan and a month of struggle on Keto.
    I enjoy the freedom and balance of including some safe starches.
    I do ~16/8 IF with 2 reasonably big meals a day. Everything so far makes sense but I struggle with some indigestion and bloating following safe starch (potato/rice) and meat combination. The food sits in my stomach for hours it seems…

    What is your take on food combining / sequential eating for optimal digestion? Some links to give you context if you are not familiar with the ideas.

    be well

  31. Hi Paul, I’m starting to see the effects of the lowering of estrogen (I’m 45) . A friend found that eating a couple of dates every day gave her a real boost and helped with estrogen-lowered symptoms. Do you think it would be OK to eat them? If so would it be better to eat them in combination with something else because of the sugar? Thanks!

    • Hi Clare,

      Yes, eating dates (and all fruits) is good to do. You don’t need to eat them in combination with anything (it is starch that may benefit from combination).

      Best, Paul

  32. Paul,



    “a new paper suggests supplemental choline is clot enhancing. That’s bad. ”


    • I read that quickly, but if I understood it, the problems are due to the TMAO production.

      If so, we shouldn’t worry, I belief.

      Supplemental choline is absorbed worse than choline in eggs. If you eat two eggs at once, that amount of choline should be almost totally absorbed in your bowel before reaching the colon, so there will be residues at most for bacteria to ferment.

      If you eat three or more yolks at the same time, it may be a different story, but I don’t know. Just in case I wouldn’t eat my weekly dosage of eggs in one meal, but otderwise I wouldn’t worry. And the microbiota on the PHD is better than the average microbiotao which should also help, I guess.

  33. I can be more specific.
    3-7 eggs a day plus 500 mg of Choline, too much?

    TC: 333 (ugh)
    HDL: 92 (great!)
    TC/HDL: 3.6 (excellent?)
    Triglycerides: 86 (great)
    Tris/HDL: 0.9 (great)
    LDL: 224 (OUCH!)
    Testosterone: 742
    Male age 50
    11% body fat


    • Hi Evan,

      Yes, we recommend getting 500 mg/day choline total. If you are eating the eggs you will get it so there’s no reason to supplement.

      Re the high LDL, definitely you should work on fixing that. Be sure to donate blood and aim for ferritin 50-100. Be sure to treat hypothyroidism. Do intermittent fasting and circadian rhythm entrainment. Be sure to optimize immunity-related and CVD-related nutrients like vitamins A, D, K2, C, and N-acetylcysteine. I can’t advise on drugs, sorry.

      Best, Paul

  34. last info:
    Diet, following PHD for 6 years, safe starches, no peanuts (lol), low toxins, meats and veggies, no sugars, etc….
    at 2400 calories a day, 25% carbs, 50% fat, 25% protein
    Plus supplements per your recommendation in the book. Exercise regularly, but sleep is limited!


  35. (taking, K2, C, D, etc, as per PHD)
    TSH 1.84 uIU/ml
    Thyroxine (t4) 5.6 ug/dl
    T3 uptake 28%
    Free T4 index 1.6
    last coronary artery calcium scan, age 46, Score: 0

    maybe I just eat too much eggs and meat.

  36. Hi,
    Does anyone know what can cause 6 toes in a baby (polydactyly) otherwise healthy. I was eating a healthy PHD type diet for few years. Previously had healthy kids. Not sure what went wrong this time to cause the defect. Baby was miscarried due to other reasons.
    If anyone can lead me in the right direction so I can prevent this happening again I would be grateful.
    Thank you

  37. Hi Paul,

    Firstly, thanks so much for always answering questions -I think it’s fantastic. My husband and I have been following your diet loosely for the last 2-3 months. We’re enjoying it and do feel like this is a long term plan to implement for life….it’s the first time I can say that about any eating plan which is great. We’ve been super busy but plan to implement the rest from September when things calm down. My question is about my husband – he had a small spell of gout a month or so into the diet (so I’m trying to be more careful about weighing protein), but also his bowel movements have reduced, even though he eats quite a lot of fruit etc. Any suggestions on what might be causing that? We;re trying to eat in a balanced way…but maybe we just need to get the diet to that ideal state? Many thanks, Clare

    • Hi Clare,

      Gout is primarily caused by energy (ATP) depletion in the liver. Certain things, primarily alcohol, require ATP to process and deprive ATP of phosphate generating AMP, adenosine, and uric acid which lodges in joints.

      So you can immediately improve things by reducing consumption of things that deplete ATP in the liver, like alcohol and added sugar, and eating things that restore it, like coconut milk, fruit and starch. I would highly recommend adding coconut milk (6 tbsp per day) to food and minimizing alcohol, replacing it with vinegar-flavored water. He might consider whether he is undereating carbs or protein.

      Best, Paul

  38. Hi Paul,

    May I ask about your opinion on diet for Crohns and parasite infections.

    I’ve read no fruit, no sugars (local honey etc) in any form, no grains, including white rice. No tapioca or cassava or arrowroot etc.

    I was wondering about the carbs and parasites. In particular do you know much about Strongaliods, would love to hear from you!

    Best regards,
    Dean T

    • There is a very good diet that has been tested in clinical essays with veny good results. The name is CDED, for Crohn’s Disease Exclusion Diet. I’ve studied all the diets out there for Crodn’s, and in my opinion —and according to the studies— this is the better.

      I also suffer from Crohn’s and totally recommend it.

      It has a lot of good things incorporated on it. So even thought you and I may have different issues, the diet is likely to help both of us. For example, I wasn’t able to tolerate FODMAPs but that diet is already low in FODMAPs.

      However, I would modify the diet in a few things. For example, instead of the eggs, eat the yolks. Whites are too immunogenic for someone with a damage gut. I would also avoid tomato, it produces symptoms in a lot of patients. And after the first stage, I would not reintroduce wheat or other likely problematic foods.

      Also, I would stick to the potato instead of the rice. In that situation you need a bunch of nutrients, and potato are better at it. Also, for some reason rice is very immunogenic in Crohn’s patients according to some studies. My own experience agrees with that notion.

      Probably there is more to say but this is all that is coming to my mind now, ask me again if you need further info.

      • By the way, I don’t think Crohn’s is caused by parasites. When you talk about it in your comment, I don’t know if you imply it.

        Anyway, infections or parasites could be a complication, that’s true. You may discuss it with your doctor if you suspect it. But otherwise try not to limit your diet further if you have no real proof.

        The microbiota is hard to change while being on a flare. Some bacteria can thrive on inflammatory states. And the immune system becomes stressed and collapses because due to the damaged barrier a lot of allergens, LPS, and bacteria can enter tissues and the blood.

        So, the CDED will help a lot in that regard because it’s rich in resistant starch, pectin, etc, that specifically feed bacteria that have been shown to help in Crohn’s, while it’s low in allergens and offenders. But we can’t get a good microbiota unless the inflammation ceases. So focus on reaching remission first, and not the other way around.

  39. hello,

    i recently read your book and found it very interesting and enlightening. i have been vegan for a while now, not for my health but for ethical reasons:


    anyway i was wondering with supplements etc if there was a way to square the circle and achieve something approaching optimal nutrition and health while not eating animal products. given that legumes and soy products are toxic for humans, i believe that only leaves bi-valves as protein sources that fit in the overlapping section of the venn diagram, if that makes sense. at any rate i’d be curious to know what you think. thanks!

  40. Hello Paul,

    What is your opinion on regularly using herbs that support liver health such as Milk Thistle, Dandelion, and Oregon Grape root?


  41. Hi Paul,

    What are your thoughts on this statement, currently going viral, from Harvard professor, Karin Michaels, explaining that coconut oil is pure poison and oils such as corn oil etc. are a much healthier alternative?



  42. Hi, I am concerned about the amount of grass fed cows butter and goat butter I am consuming. Should there be a limit? I am a 21 year old girl and have been following a version of the diet for a few years. I do not restrict my fat intake at all, and consume mostly in the form of butter. I might eat a stick a day. In addition I eat tons of dark chocolate, avos, olives, and egg yolks. I am thin – 109 and 5’6 but I am concerned about my cholesterol levels and my heart. Heart disease runs in my family and I have been getting chest and arm pains recently along with anxiety. Should one limit their consumption of butter? What is a maximum amount? Thank you!

    • Hi Sam, The recommended fat & oil intake on PHD is 2 tbsp per day. A tablespoon of butter has about 100 calories so 2 tbsp would be 200 calories. That would assume no use of oils.

      A stick of butter is about 8 tbsp, 800 calories, which is definitely excessive. You should cut back and add more natural whole foods. You may be undereating micronutrients, carbs, or protein.

      Best, Paul

  43. Hi Paul,
    I have seen recommendations here and there on the Q and A. For example, the post above says 2 T a day of fats and oil. I also saw something about a food plate and keeping servings to 4 oz. I have read the book and am spending a lot of time on the webaite trying to get the gist of this. I am thrilled to get started, but I am wondering where I can find a summary of all of that type of information. I don’t recall reading those specifics in the book; it’s not in the color companion I downloaded; and it’s not on the apple diagram. Suggestions?

    • Hi Sara,

      “The Diet” page is the best for a quick summary. A good rule of thumb is: keep the physical sizes about the same on your plate of (1) animal foods, (2) starch, (3) sweet plant, (4) vegetable; then flavor to taste with (5) fats/oils, (6) beneficial acids, (7) fermented (umami) flavorings, and (8) stock from bones/joints/tendons. Total quantity of food should match your appetite, proportions should match the above plus your taste.

      Best, Paul

      • Thanks Paul! That helps. One more set of questions as we are planning our grocery list for next week. We are having a hard time sorting out the dairy.

        What kinds of cheeses can we eat? What kind of yogurt? Trying to avoid cow’s milk, but maybe we don’t need to do that. Should we go organic? Do we need to do almond milk? Do we need to eat raw cheese? What guidelines can you offer for our diary choices?

  44. Sharon McGlinchey

    When you refer to a particular quantity of protein, is it cooked or uncooked or does it even matter?

    • Hi Sharon,

      When we refer to a nutrient, such as protein, it is generally by calories. Sometimes other people use grams, but this creates confusion over whether the reference is to the amount of food or the amount of nutrient.

      When we refer to an amount of food, such as meat, we generally use weight in grams or pounds. This refers to the naturally hydrated weight. For most foods, cooked gently, this will be the same cooked or uncooked. Harsh cooking will generally dry/dessicate foods and reduce their weight; in that case we generally refer to the uncooked weight. In case of foods that are sold dehydrated and then rehydrated by cooking in water, such as rice, we mean the cooked (hydrated) weight.

      Best, Paul

  45. Paul,

    Thank you for sharing this important work!

    I saw your talk on healing infections at the Paleo Convention in Berlin (2015) online. You talk about WBC and how 4.5 is roughly the ideal. MY WBC were 4.5 and then dropped to around 3.2 a few months later. Any idea why this might be? My serum zinc levels are fine, everything else seems to check out fine. I was thinking it might be a sign of a chronic infection, but you say that a higher count tends to indicate that. Any thoughts? Thank you!!

    • Hi Nikki,

      Your situation can be a bit complicated — either you have a single process that lowered WBC count recently, or there can be competing processes, one lowering WBC count and one raising it, that lead to a reading that is sometimes low and sometimes normal or even high. It’s impossible to say what may be going on from a distance, but you should consider all symptoms and lab values to look for clues about what may be going on. If the WBC was only low once, there’s no reason to think any infection was chronic rather than acute. Sometimes people just get sick for a few days.

      Best, Paul

      • Hi Paul,

        Thank you for your input. The WBC count has been hovering at 3.2 for a year now.

        The progression has been like this (normal range starts at 4.5):
        4.6 in November 2016
        4.0 in January 2017
        4.6 in July 2017
        3.1 in October 2017
        I’ve had blood drawn 5 more times in the last year (every specialist wants to draw more!) and it has remained in the low 3’s.

        It’s a mystery to me! I have had other strange symptoms that prompted the doctor’s visits in the first place – shortness of breath, trouble swallowing, peripheral neuropathy, fatigue, small random bruising on my legs. Some has improved with diet but not completely. I feel that I have many food sensitivities as well.

        The only other abnormal things on the bloodwork is slightly elevated bilirubin (range is 0-1.2 and mine is 2.0) and slightly positive ANA.

        Of the WBCs, neutrophils and lymphocytes are the ones that hover around abnormal levels.

        Any thoughts? I so wish that I could attend one of your retreats but I see that you are busy curing cancer! It has been fun to follow along.

        Thanks so much,


  46. Hi Paul. We are having a hard time sorting out the dairy.

    What kinds of cheeses can we eat? What kind of yogurt? Trying to avoid cow’s milk, but maybe we don’t need to do that if it’s not raw milk. Should we go organic? Do we need to eat raw cheese or is a hard cheddar okay? What guidelines can you offer for our diary choices?


    • Hi Sara,

      You can eat any kind of cheese, but avoid moldy cheeses if you have fungal infections. You can eat any yogurt. The exceptions are if you have a dairy sensitivity or autoimmune diseases associated with sensitivity to mammalian sugars, e.g. Hashimoto’s. You don’t need to drink raw milk, in fact I’d advise against it — but milk from pastured cows is better.

      Best, Paul

  47. Thanks Paul. I am amazed at your ability to keep up with everyone’s post. I have to thank you for having this Q and A section. We just started PHD a week ago and I have used this section every day to search for questions that may have already been asked.

    I am starting PHD for a couple reasons. I have had GERD since I was little and have had scopes and tried a variety of meds. Finally found one that works and they recently took me off of the meds due to studies saying it causes dementia. I am okay with that because I don’t care for meds anyhow, but have been miserable ever since with acid reflux and heartburn. I also have something called EOE in my esophagus. After extensive allergy testing, the thought was to try PHD in the hopes of alleviating both of these issues. The icing on the cake was when I read several blogs about PHD alleviating symptoms of OCD and anxiety. I have dealt with these symptoms since I was 16 years old and have managed with therapy, meditation, yoga and exercise.

    Anyhow, my point of this was that if you have any additional suggestions based on those diagnoses, I would love to hear them! We are focusing on the diet portion right now to try and familiarize ourselves, and will begin adding in the supplements, exercise, etc. in a couple weeks. Thanks!

  48. Hi Paul,

    What is your opinion on treating Psoriasis? Any other recommendations besides implementing PHD diet&lifestyle? What is your opinion on using steroid topical creams?


  49. Paul on a 2700 calorie diet, what would the macro pct be? I’m 30 extremely active between work and exercise. 6’4 165 lbs looking to gain 15 lbs while maintaining/achieving optimal health. Thank yoh

    • Protein up to 600 kcals. Desirable to keep the amount no much higher than 500. The higher extreme has metabolic advantages because it’s a way to tell your body that there are resources out there to invert into fertility, muscles etc; but the amount to repair and build muscle is low indeed, so don’t worry about eating too much protein. You can optimize proteins with a good diet and lifestyle which helps a lot too. E.g. fasting increases growth hormone a lot! So if you were doing strenght training you could fast, do the trainning, and then eat. Eating the carbohydrates after exercising is a way to use insulin peaks into your favour.

      Carbohydrate minimum of 600 kcals (500 kcals from starch, about 100 kcals from fructose; fructose will help to replenish glycogen too). Add starch calories depending on your activity, from 100 to 500 per hour of exercise. More calories than your expenditure will help to gain weight if you desire so.

      Fat: as much as you need to complete your caloric needs. Saturated fat and monounsaturated fat are healthy and will help to build muscle too.

      However, if you were eating more calories than your caloric expenditure because you wanted to gain weight, —and I don’t know if Paul would agree with me on the following—, I think that saturated fat can be harmful in that case. So I would try to favour monounsaturated fat over saturated fat if your diet has a considerable caloric surplus.

      Now, instead of eating a steady amount every day, try to eat more on the training days, and eat less on the resting days.

      If you have problems to eat much, favour white rice. It will digest quick and allow you to keep exercising and eating.

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