Dear Mark: Resistant Starch, Zinc Deficiency, and Something New

FloursFor today’s edition of Dear Mark, we’ve got a three-parter. In the first section, I discuss the extremely hot (and then allowed to cool off) topic of resistant starch, explaining who might benefit from it, who might not, and where you can find further information on the subject. Second, I briefly go over how a zinc deficiency might arise and how you can address it on a Primal eating plan. The third section is bit of a surprise, featuring a very special guest writer. Since this is text and you guys can just skip ahead to see who it is, there’s admittedly very little suspense. But still. It’s a surprise that I think you’ll enjoy and appreciate.

Let’s go:

What about so-called resistant starch, that is, starch that passes undigested through the stomach but arrives in the colon? There’s some emerging evidence that the good bacteria that live in the colon need to feed on this starch in order to thrive. In other words, if everything is processed by the stomach and small intestine, the good “microbiome” is underfed, and the bad guys can multiply. An unhealthy microbiome may be tied to all sorts of auto-immune diseases. Do we need some resistant starch in our diets?

Resistant starch has really been making waves in the Primal health community. Lots of talk in the MDA forums and elsewhere.

So what’s the deal?

Resistant starch is a starch that resists digestion by regular digestive enzymes, passing through to the colon for fermentation by gut flora. In a post way back in the day, I addressed resistant starch and lumped it in with other prebiotic fibers like inulin, with the reasoning being that while it was certainly helpful and important, it was not some essential, magical nutrient. It seems I underestimated it. Resistant starch offers some interesting properties unique among other prebiotics.

Remember that starch post from a couple week’s back where I compared the fiber content of the kind of wild tubers our ancestors would have encountered to modern cultivated tubers? Much of the “fibrous material” would have been resistant starch, a highly efficient, durable method of energy storage for a plant’s underground storage organ. In the wild, where a plant isn’t protected from pests by agricultural chemicals or physical barriers, resistant starch makes sense. And so when we ate these tubers, we’d get a nice dose of resistant starch, particularly if we ate them raw or undercooked (cooking degrades the majority of resistant starch into regular old highly digestible starch).

Before agriculture, our ancestors obtained resistant starch and other fermentable fibers by eating a diversity of wild plant foods, bulbs, corms, tubers, cattails, cactuses, and medicinal barks – foods that by and large are not available to us nowadays (and if they were, they wouldn’t be very desirable or delicious). According to some estimates, they consumed up to 135 grams of fermentable fiber a day, and their gut flora would have reflected that. Nowadays, the most common sources of resistant starch in the modern diet (PDF) include various legumes, raw oats, and even certain types of bread that’s been frozen for 30 days. Raw potatoes, green bananas, and raw plantains are also quite high in resistant starch, but few people are eating them in their raw state. It’s much more delicious to cook them. We also have reliable means to cook our foods well enough to break down most of the resistant starch, like microwaves, ovens, and stoves. So, the result is many people following a Primal lifestyle – avoiding legumes and grains while cooking and reheating their starches – are also missing out on an important source of prebiotics and, perhaps, optimal gut health.

There’s a quandary, then. Resistant starch seems to promote ancestral-esque gut health and floral composition. How do we get resistant starch without foraging for wild foods or eating ungodly amounts of legumes, raw grains, and previously-frozen bread (thus incurring many of the negative aspects of these foods, like gut-damaging lectins, phytic acid, and/or gluten) or raw plantains and potatoes?

Unmodified, raw potato starch is probably the easiest way to get resistant starch, since each tablespoon contains about 8 grams of RS. Richard Nikoley has spearheaded the promotion of resistant starch via unmodified potato starch as a way to approximate or emulate the ancestral microbiome over at his blog. He’s been covering the benefits and relaying lots of anecdotes from readers who’ve seen great improvements in sleep quality and blood sugar control, even when diabetic or while remaining in ketosis). He even came up with a way to make mashed potatoes that don’t spike your glucose. Interesting, compelling stuff.

I think it’s worth trying. Potato starch is only about $4 or $5 a bag (less if you order in bulk on Amazon), mixes well in water or smoothies without much of a taste. Start with a teaspoon or two and work your way up to as many as four tablespoons. Expect flatulence as your gut flora acclimatize to the influx of this food.

Anyone with digestive issues, particularly FODMAP intolerance or IBS, may want to exercise caution as fermentable carbohydrates often irritate or exacerbate those issues. On the other hand, there’s preliminary (and mostly theoretical, as it hasn’t been directly tested) evidence that resistant starch may actually treat small intestinal bacterial overgrowth by “flushing” the pathogenic bacteria out in the feces. Adding resistant starch to the rehydration formula given to cholera patients, for example, is an effective treatment because the cholera bacteria attach themselves to the starch granules almost immediately.

Anyone else try this? What have they noticed?

I attended a nutrition study course over the weekend and several vitamin deficiencies were discussed. Each delegate was also given a vial with a stopper of zinc solution to test ourselves for deficiency. I basically could taste nothing and despite being on an ancestral diet for over a year now, am apparently zinc deficient, which is worrying. I just wondered whether the zinc taste test had any merit? On a side note, this has since led me to investigate the whole nuts/phytic acid binding minerals issue and despite soaking and drying my nuts, I consume WAY too many which may be the cause of this deficiency if it indeed exists. Thanks for your attention to this matter.


The zinc test definitely has merit. In a study of pregnant women (whose zinc levels tend to drop as the pregnancy progresses), the accuracy of the zinc taste test ranged between 70-100%. Overall, the results of the test correlated strongly with zinc status. I see no indication that the test is only valid in pregnant women; anyone who’s deficient enough should qualify.

The nuts could be a problem. Low to moderate amounts (an ounce or two a day) aren’t an issue in the context of a nutritious Primal way of eating, but eating “way too many” will eventually impact nutrient absorption via phytate binding because, unfortunately, zinc is susceptible to phytate.

Meanwhile, adding phytase (which degrades phytate) to zinc-rich foods increases the absorption of zinc. It’s pretty clear that excessive phytate is a problem. How much phytate? I don’t have a hard figure for that, but being deficient in zinc despite eating Primally is a good indicator.

So, what should you do?

Eat enough selenium. It’s responsible for regulating the delivery of zinc to zinc enzymes throughout the body for proper zinc metabolism. Seafood like wild salmon is a good source of selenium. Eggs, too. And the very best of all is the Brazil nut. One or two Brazil nuts should get you to the RDA for selenium without giving too large a dose of phytate.

Make sure you’re actually eating enough zinc, of course. Oysters, red meat (beef, lamb, bison), and scallops are some of the richest sources.

Limit sources of phytate. Stick to the ounce or two of nuts per day, not however many you were eating previously. Consider subbing in some macadamias, which are among the lowest in phytates, and keep soaking the nuts you do consume (not mac nuts, though).

When you do eat phytate-rich foods, give yourself a couple hours in either direction before eating zinc-rich foods. This shouldn’t be too tough, since nuts are snacks more than meal components. It does mean that your oyster sliders on almond meal bread might not be a good option, sadly.

Eat zinc with animal protein. Studies show that animal protein can counteract the inhibitory effects of phytic acid on zinc absorption (PDF). Luckily, zinc usually comes with animal protein already attached. Handy!

Account for excessive sweating. Sweating is a good thing, usually, because it indicates vigorous physical activity, but it also depletes zinc. You may need to account for sweating by eating more zinc.

Supplement. In my view, Krebs cycle intermediaries (citrate, fumarate, succinate, etc.) are going to be your best bet for zinc.

Now for the surprise…

I get a lot of questions from women, and for the most part they’re very general, straightforward, and applicable to men, too. But there are times when a uniquely female perspective (that I simply cannot provide) would come in handy. Since I frequently bug Carrie for advice on this question or that one, I figured why not have her contribute directly to the blog and answer reader questions? She’s already done reader question roundupsdiscussed cellulite, and talked hot flashes in the past and she has a level of expertise on some topics that I don’t. In addition to being smart, beautiful, fearless, and kind, Carrie has a Master’s degree in Spiritual Psychology from the University of Santa Monica and serves as a group leader at intensive weekend spiritual psychology retreats on a monthly basis. She has participated in retreats in Los Angeles, and as far away as Norway. Carrie is hard at work on her long-awaited book, Primal Woman, which is due to be published in the fall of 2014.

Without further ado, let me introduce Carrie.

Mark, I really wish you would’ve addressed women’s cycles and necessary starch for menstruation. So many women lose their cycles only eating berries and salads. I know I did. Add back in a sweet potato, some bananas, and yes even some white potatoes and white rice. BAM! Flow city. ;)

Carrie here. I’m not Mark but I can handle this question.

First off, thanks for your question.

Personally, I never really had this issue, even though I’ve always been pretty active, because I always made sure to eat enough food. Not too much, not too little, just enough to keep me full, help me recover, and maintain my hormone levels. The only time I ever had any issues with my cycle was when I was on a strict low-fat, “heart healthy” diet full of whole grains and other starchy carbohydrates while doing tons of cardio. Of course, I wasn’t really Primal until menopause, so I can’t really say that it wouldn’t have happened if I’d been eating this way back then. That said, the research shows that the biggest variable for regular menstruation is sufficient calorie intake. Not sufficient potatoes, rice, or bananas. Not carbs. Calories. You need them if you want to maintain a normal cycle. Your body needs to know that you’ve got energy coming in before it decides you’re ready to conceive.

Study after study shows that dieting can have a negative effect on the menstrual cycle. Let’s go through some of the research.

Like here, a 1000 calorie high-carb diet caused menstrual irregularities. Women who lost the most weight (had the biggest energy deficit, in other words) had the most irregularities. All that starch wasn’t enough to overcome a super low calorie intake.

Or here, where a vegetarian diet caused 7 of 9 women to stop ovulating, while just 2 out of 9 women in the non-vegetarian group did. Both groups lost the same amount of weight (though they don’t give a calorie count), so it was something about the vegetarian diet, not just the energy balance.

Another study showed that an 800 calorie vegetarian diet disrupts menstruation. In fact, vegetarianism seems to be especially linked to menstrual cycle disturbances (although not so much in healthy, weight-stable vegetarian women eating adequate amounts of nutrient-dense food).

They’ve even found that something called a “drive for thinness” (which I’d never heard of) is strongly associated with disrupted cycles because it leads to huge energy deficits – too much exercise and not enough food.

See the common thread? Low calorie intake. The literature is rife with examples of young, healthy women losing their period after going on a low-calorie diet, whether high-carb or not. And that calorie requirement goes up the more you exercise, which is why the “female athlete triad” – excessive energy imbalance, loss of period, and bone weakening – is a common affliction.

That’s what jumps out at me when people talk about adding in sweet potatoes to jump start their cycle: they’re adding calories to their diet. They’re not substituting potatoes for something else. They’re adding it to whatever else they were eating, resulting in a net increase in calories, and that’s fixing the issue.

If carbs are the only way you can add enough calories to your diet to restart your cycle, then go for it. But it’s not a quality inherent to the carbs. It’s just the energy they provide. The calories. I hope this helps and I will also share about some other self-honoring choices I made during my cycle that I will post in a future column.

Keep the questions coming, folks. Carrie’s agreed to chime in every Monday, so send along any questions you might have for her, too. Thanks for reading!

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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140 thoughts on “Dear Mark: Resistant Starch, Zinc Deficiency, and Something New”

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  1. Interesting question about the zinc. From the study you linked it doesn’t seem like sweating should affect it too much, I agree that it’s probably an intake or phytic acid issue.

    However this has prompted a new question for me, which is, is it necessary to get tested for deficiencies regularly, and if so what intervals make sense?

    1. I think it’s the other way around. If you taste it you’re not deficient (tastes nasty); if it tastes like water then you are deficient.

      1. I guess I’m not zinc-deficient then. I use a cold-eeze spray and that stuff is plain awful! But it works!!

        1. Cold-eeze is not the same as a zinc tally test. Even though I test as deficient on the test, cold-eeze lozenges still taste pretty nasty to me.

      2. Correct, and if the zinc tally liquid tastes sweet, then you’re VERY deficient.

        Both the zinc tally taste test and resistant-starch rich foods are tools in my Primal toolbox.

        The zinc tally test helps me keep my zinc levels up and the RS improved my blood sugar control.

      3. That was my understanding from the taste test: water, no taste-deficient, like sucking on a metal pipe- NOT deficient, furry taste in mouth, on the border.

        1. I have a question.. how do you use toe RS? Besides smoothies which I do not like, can you put RS in cooked foods? Thanks 🙂

      4. Miriam – Yes! Oops, I mixed them up. If it tastes like water then you’re deficient. If you have adequate levels of zinc it should taste horrible!

  2. Three very interesting topics! Thank you. I need to mull them over a bit. I look forward to hearing more from Carrie on Mondays. 🙂

  3. I’m going to have to disagree with the claim that starchy carbs are necessary for healthy hormonal function and menstrual regularity. While a very low calorie intake does play a very significant role in the loss of menstruation for all women, there have been studies that show that for some women eating at maintenance but eating a diet low in or void of starchy carbs will cause menstruation to become irregular or stop completely.For those women, an appropriate caloric intake AND appropriate starchy carb intake is necessary.

    1. I agree. Especially since looking at PCOS:Unlocked, the manual by Stefani Ruper, I’ve learned that “thin” PCOS or PCOS without insulin resistance or obesity is often due to stress on the body, and one way to remedy it is to eat more carbs (along with sleeping more, exercising more efficiently, etc). I have started incorporating more carbs into my diet, while still eating the same amount of calories because I track them on myfitnesspal (shame on me, I know) and not really sleeping more because i’ve always slept 8-10 hours a night, and my cycle has gone from being so wacky that I even got my periods twice a month sometimes to being a perfect 28 day cycle with less cramping and PMS.

      1. Just wanted to clarify if you’re equating having ‘thin’ PCOS to not being insulin resistant? Or just that some women with ‘thin’ PCOS aren’t insulin resistant?
        Many people who are thin, such as thin diabetics or women with ‘thin’ PCOS, are also insulin resistant. Not being overweight does not keep people from being insulin resistant, unfortunately.

        1. No, I am saying that people often refer to PCOS in which the person does not have insulin resistance as “thin PCOS” because that person typically doesn’t fit the PCOS-stereotype of having metabolic syndrome. I know that thin people can be insulin resistant. I guess the clearer term to use is just non-insulin resistant PCOS, which seems to affect thin or normal weight women more than overweight ones. It’s also called type II PCOS since it is stress induced, rather than insulin-resistance induced. I do concede that limiting carbs can help those with insulin-resistance to regulate their cycles, but the general idea that carbs play no role in hormonal regulation for some is false.

        2. @janelle1122 I know this is a bit late to address, but the reason PCOS symptoms become worse with a high animal protein diet is because of the lactic acid within the meat. There are only four natural instances where your body will become insulin resistant for a good reason. They are:

          Breast Feeding
          Healing of Tissue or Muscle damage (natural lactic acid build up)

          The meat, when slaughtered, has a high amount of lactic acid develop. When ingested, this lactic acid in high amounts can mimic our production of lactic acid and in-turn increase insulin resistance. The only real side note to this would be in fish protein. Due to the cold water that they are usually slaughtered in, this seems to decrease the amount of lactic acid that the animal sends into it’s tissue upon death.

      2. I think you are just not fat-adapted yet and cutting your carbs caused stress to your body that still can’t use the calories from fat well. As I am allergic to most plant foods, I have been eating low carb since being a kid. The only time when my cycles stop is when I change my diet and add more starch from potatoes or sugar from chocolate. I also get cramps and mood swings when eating more carbs… Your body is probably stressed because of the sudden change and adding more carbs is a good thing until you are fully fat adapted.

        1. Nope, I’m pretty sure I was fat adapted, as I had been eating a 70% fat, 25% protein, 5% carb diet for 5 years, averaging 30 g of net carbs a day. I’m pretty sure cutting my carbs for five years isn’t a sudden change that my body is responding to, but is rather a chronic stressor that impeded normal hormonal production. In fact, my PCOS symptoms only became apparent after I adopted a low carb diet ad gradually became worse the longer I stuck to restricting carbs. That only made my periods worse. And now that I recently bit the bullet and incorporated more carbs, not necessarily HIGH carb per se, now averaging about 100 g of net carbs a day, my cycles are much more normalized and most of my PCOS symptoms have been alleviated. Again, every person’s body is different. Isn’t that why we advocate N=1 experiments? For one woman, carbs may inhibit hormonal production, but for another, they may support it.

        2. I believe you! I feel great and in control at 75-100g carbs, and it seems to help calm my urge to overeat while still allowing a serving of starch and a serving of fruit a day. I’m very happy here.

  4. I’ve noticed a few things really improved my Fasting Blood Sugar. The first two were primal eating, and magnesium supplementation. I think the magnesium really helped a lot. I also lowered by iron stores through blood donation. Even with all those, my FBG would still be in the high 90s or low 100s when I measured it, and it could spike to 160 or so after a higher carb meal. When I added the resistant starch, in the form of Bob’s Red Mill Potato starch, it lowered FBG to the low 90s/high 80s area, and when I tested a fairly high carb meal, noticed it only spiked to 125. I certainly think there is value in adding some to your diet,

  5. Supplementing with zinc can be problematic since zinc will block copper absorption. Best to get it from food unless one is very deficient. Trace minerals are intended to be just that. Adding more through supplementation can disrupt the body’s natural chemical balance.

    1. I had a zinc deficiency for years and NO dietary changes helped it. None. The only thing that helped was a zinc supplement. There are zinc supplements that include copper so no worries there.

      1. Same here. I became zinc deficient while eating plenty of red meat and going gluten free didn’t fix it. The first time I supplemented zinc, I had vivid dreams. Now I dream whenever I eat red meat… so I reckon things must be improving.

        1. And same here too, zinc-rich foods like red meat and oysters did not resolve my moderate zinc deficiency, nor did trace minerals, which were way too low in zinc to make a dent in my deficiency. Only high-quality zinc supplements helped. I wish it were otherwise.

          I’m working hard to find a way to improve my body’s ability to absorb zinc and other minerals so I won’t need supplements. In the meantime, thank goodness for zinc supplements.

          Some people like me have chronically high copper levels and need to reduce them rather than maintain or increase them, So zinc supplements have also been great for me with that.

  6. I’m highly interested in potato starch. I make smoothies all the time so it would be easy to incorporate. Question… you say unmodified, raw potato starch. Would the stuff I can get at the healthfood store be good or is it modified in some way? You say it’s cheap though so I’m thinking the stuff from the bakery section would be just fine. Info please?

    1. Bob’s Red Mill potato starch says unmodified on the package, which means raw.

    2. Use any kind of potato starch sold as food. Just make sure it’s not potato flour, that won’t work. Normally the package will say ‘unmodified’. In Europe the terms ‘potato starch’ and ‘potato flour’ are used interchangeably, but not in US. By ‘Raw’, we mean ‘not cooked’. Take it right from the bag and dump in your smoothie. It also mixes well with kefir, yogurt, or water. Has no taste. Start with 1TBS and work slowly up to 4TBS over a month or two. If you get gassy, that’s OK, it means your gut flora is adjusting–just cut dose in half for a while.

      Long-term, potato starch is good to keep around and add to smoothies or whatever. Yo won’t need it every day of your life, in fact it’s good to take a break now and then, especially when eating other RS rich foods.

  7. And now a comment… I do think carbs play some part in menstrual cycles. A couple weeks ago I couldn’t get enough squash. I made squash and sweet potato casseroles three times in a row. Then my cycle started. Coincidence? I think not. 🙂 But even when I ignored any cravings for carbs I still had my cycle, so I would agree that calories are more important.

    1. I guess my only question here is how do you *know* it was the carbs and not the extra calories? Did you literally switch one out for another and hit the same calorie count via tracking?

      I honestly wonder. Thanks 🙂

  8. I’ve been doing a cycling approach with the potato starch for about 6 months now–1-2 weeks on, 1 week off, and it’s been really good. Definitely a noticeable adaptation period, whether you’re sensitive to FODMAPS or not, so be ready for that. I’ve been experimenting with opposite-week cycling of fermented foods as well (sauerkraut, kombucha, yogurt), since having both the pre- and probiotics every day can become a bit voluminous…

  9. During three months in ketosis I always got my periods regularly. Like Carrie, when I did low fat higher carb I didn’t, so I’m going to have to agree with her that overall calorie intake is the key factor. I also happen to think that fat is important for women for the metabolism of hormones, especially oestrogen.

    1. Agreed. I’ve eaten 30g or fewer a day of carbs for a few years with no adverse effects to my cycle. In fact, it has become even more regular and predictable and cramping and mood disturbances have disappeared.

    2. Same here, even going for 3 months with no carbs whatsoever. I’d imaginge that a lot of women trying paleo are still afraid of fat, which would lead to too little calories.

    3. I must be an oddball, because my cycles become less frequent with exercise, no matter what or how much I eat.

  10. Foraging for your resistant starches isn’t as difficult as it sounds. Broadleaf cattail, for instance, is found all over the world and native to all U.S. states except Hawaii, where it is introduced. A quick Google search for the plant images will help with identification. And what’s more Primal than eating the real foods (aka wild foods) of our ancestors’ time?

    1. Burdock root is also a great and easily found source of prebiotic starch as are sunchokes (Jerusalem artichoke). Just be careful if you want to grow your own suncokes as they are a very very weedy plant and will take right over wherever you plant them.

      1. Yes indeed! Calling it prolific does not do this plant justice!

  11. Speaking of superior colonic health, Hubby has it–he just had a colonoscopy this morning, and passed with flying colors. I had mine last July, and also passed easily.

    In both cases, the doctors were freaked out by the ketogenic diet we both answered on the questionnaire where it said LIST DIET. Also, we were both instructed to increase our fiber intake–how do they know what our current intake is? I don’t think anybody eats more avocados or coconut flour baked goods than we do! We’re also on the verge of eating lard with a spoon to be sure we get enough fat from varied sources.

    And after that article here about fiber (, I say “FIBER SCHMIBER!”

    Since we came in with the keto diet, we’re going home to the keto diet, and sticking with it until death. We plan to deprive the medicine-as-revolving-door industry of as much as we can get away with.

  12. I don’t eat a lot of nuts, but do go overboard at times on nut butter, usually sunflower nut butter mixed with some coconut oil (yummy!). Do nut butters also have phytates??

    1. Yes — lots. Sorry. Nut butters are even more dangerous than nuts for some people, because it is so easy to go overboard and consume an amount in one sitting that our ancestors would have had to work very hard for. All we have to do is unscrew a lid and BAM, there it is.

      1. Thanks so much for the info. Bummer! Yes it is waaay too easy to load up on nut butter.

        1. But sunbutter is a seed butter, not a nut butter… Does that make a difference?

  13. I’ve supplemented with 30mg Zinc daily for ~3 years and definitely noticed positive effects, mainly my skin looking much better (used to have a bit of acne), and almost never getting a cold.

    Warning with Brazil nuts: I tried having 5-6/day since they are delicious, but got acne breakouts, which disappeared when I stopped eating them. 1/day seems to be fine though.

  14. I have eaten my way through about 2 lbs of raw, unmodified potato starch in the past 3 weeks, around 4 TBSP a day, in cool or lukewarm food and drink, plus dehydrated (very green and hard) plantain chips dried at about 95 F for 12 hours (thank you, TaterTot!!!). I eat the plantain chips kind of like you would ritz crackers with butter, creamed coconut or nut butter sandwiched in between. Way easier than making a baked primal cracker from nut or coconut flours and probably healthier. I have noticed even at vlc ketogenic carb levels (excluding the amount from the RS), the difficulty going #2 has gone away, but be sure you will have stomach pains if you try to load up on RS coming off of a no starch vlc diet. There is real adjustment period, like Mark and others have said, but if you take it slow, it’s worth it. I went out for my first jog in a very long time and was able to go for about 30 minutes without feeling like I wanted to take a break (albeit, I jog very slow, like most peoples fast walks) 😉 I have an easier time getting to sleep, and dream movie type dreams- crazy and fun. I hope what I’ve had to say helps motivate people to take the plunge with resistant starch. It’s good stuff!

  15. Does anyone know if Arrowroot starch would be as good as potato starch?

    1. Not as starchy–there’s a link in the article…check out the series thus far at….

  16. I’m wondering if you could add the potato starch to coffee in the morning. Butter, Coconut oil, egg, starch and coffee?

    1. I think the heat from the coffee would damage the potato starch. It’s supposed to be uncooked, raw potato starch.

      1. I drink my RS in water when I take my frozen raw liver “pill”s. The slight taste of the RS water gives me another barrier to actually tasting the raw liver. All good.

    2. I would avoid adding potato starch to hot beverages, if you are looking to increase your resistant starch intake. Heat breaks them down, and will make them more digestible. It’s somewhere around 140 degrees F where this occurs. You could try it in an iced coffee, if you like.

  17. Thanks again, Mark and Carrie, for the wealth of information and research you provide for those of us who want to know. After a couple of years so far on my Primal path, I was (yet again) highly enlightened by today’s RS post and links. Just one more piece to add to the puzzle. As I have been avoiding all starch at all costs, I now understand the butyrate connection MUCH better and realize that my Kerrygold can’t do the whole job. I’ll be starting the RS TODAY.

    My favorite takeaway from Richard Nikoley was this: “The rather hilarious thing, though, is that all of that research points to the likelihood that it’s precisely a form of starch—a completely different kind than the DEVIL’S SPAWN kinda starch—that feeds the gut biome (that other 90% of you), which in turn produces things like those ANGEL’S SPAWN short chain saturated fatty acids you love so much. And it does it in a place your cubes of butter can’t reach, producing the general effect of regulating apetite, satiation, glucose levels and by direct consequence: insulin requirements. And it’s starch that does this in the very face of the fact that an enormous plate of brisket spikes insulin.”

      1. Thanks Tatertot, I’ve been reading yours and others very informative comments on FTA, very helpful info. I bought the Bob’s RM PS today, going to start slow like Mark says. The more I learn about my 90%, the more I want to help them be all they can be.

  18. It’s coming into summer here. My favorite time to head to the rivers, lakes and beaches to soak my nuts.

  19. When I cook I’ve always mumbled here and there on the raw veggies.
    Always told I was weird for eating the potato raw.
    At least I know it’s not a bad thing!

  20. Please ALWAYS properly ferment potatoes before cooking them. There are so many reasons for the proper fermentation of potatoes before consuming. Traditional cultures never ate potatoes, grains, legumes, etc. without first preparing with 100% anaerobic fermentation methods.

    1. I have indeed found sources supporting that tubers were traditionally fermented at least some of the time, such as these:

      “Taro and related tubers are found throughout the tropical world–in Africa, the West Indies and Poly-nesia. Explorers discovered that the natives ate root vegetables after they had been buried in the ground and fermented for several days to several months.” – Sally Fallon, Nourishing Traditions, p. 102

      Tocosh (Fermented Potatoes),

      1. And fermentation increases the resistant starch content of foods that contain RS.

  21. Interesting question and answer about the menstrual cycle stuff.

    My cycles had gone to a consistent 30 to 35 day routine for years (starting in late teens when I went vegetarian and low fat, through my 20s as I continued to gain weight to the point of obesity despite routinely pinning myself down to conventional diets – super low fat! high healthy grains! more rice!! – and through two pregnancies.) The only time in all those years I had a shorter cycle was if I was on hormone birth control pills.

    I have slowly become more primal over the last year (wish I was one of those “never look back” people, but a lifetime of habits aren’t always easy to change!) … the last six months I’ve been pretty much 80/20 (most of the time), have lost 40 pounds (more to go), and the last four months my cycles have been 28 days on the nose. The first time shocked the heck out of me – it’s been at least 15 years since I had a 28 day cycle naturally. I thought it must have been a fluke. But every month since, bam, 28 days. It’s funny – I’ve lost weight, my skin has improved, my mood has improved, my strength has improved, yet somehow this thing with the 28-day cycle was really when it clicked, like “this is changing and normalizing your body on a deep down level … this is for real.”

    Anyway, not exactly what the q/a was about, but thought I’d share it 🙂

    (Hopefully this will someday be part of a Friday success story … give me another six months! Hubby has also lost 25 pounds and the whole family is slowly going primal here!)

  22. On a survival pov it’s only logical that women loose their cycle when eating too little.
    It’s your body’s reaction to a chronic shortage of food. It thinks you’re starving and concludes that there isn’t enough food to feed on. So a fetus won’t get enough nutrition without harming the mother, nor could a young child survive without a certain amount of food.
    And a tribe low on food would only be harmed by the arrival of an other child. Better to hold off reproduction untill better times.

  23. Hey guys,

    Don’t forget the retrograded starch! The raw one is the so-called type 2 (RS2) which gets destroyed above a certain temperature and moisture level (typically while cooking it). But cool it or freeze for at least 24h, some of the destroyed RS2 will retrograde into the type 3 starch (RS3). Repeat this process a few times and you increase the amount of RS3 albeit the first time around is the most effective step. RS3 resists heat as well so you can stir-fry the cooled potatoes or basmati rice. i often do this myself as I am not a big fan of the powder. I only use it when I had no RS rich foods for like a week or 2. RS3 rich foods are usually delicious because you end up stir-frying them 🙂

    1. So…what you’re saying is that LEFTOVERS…are a GOOD THING?!..Then hurrah for RS3-rich foods!!

      1. Yes, it is a GOOD THING 😀
        I often use a little duck fat or bacon dripping to stir-fry some basmati rice that I had cooked the day before. What I don’t eat will be stir-fried again after another night of cooling.

    2. So that sticky rice made into sushi rolls after it gets cold is good? Hmmmm. Sounds better to eat that once a week instead of mixing potato starch into water, but I like sushi rolls so….
      I stopped eating them once a week so that I wouldn’t get so much carbs but maybe now and then it’ll be added into my diet again.

  24. As I understand small intestinal bacterial overgrowth from Allison Siebecker, it is good commensal bacteria in the wrong location, moved from the large to the small intestine. I don’t think trying to treat it with resistant starch would be a good idea.

    1. This is why RS is NEEDED in SIBO, not AVOIDED:

      On the other hand, there’s preliminary (and mostly theoretical, as it hasn’t been directly tested) evidence that resistant starch may actually treat small intestinal bacterial overgrowth by “flushing” the pathogenic bacteria out in the feces. Adding resistant starch to the rehydration formula given to cholera patients, for example, is an effective treatment because the cholera bacteria attach themselves to the starch granules almost immediately.

    2. Tam, If you can provide any studies to support this notion that RS worsens SIBO, rather than helps it, I’d greatly appreciate it. For months I’ve been begging the people who make the claim to provide supporting evidence, with no luck so far. Instead, they tend to go silent when I ask this. I eat RS-rich foods, so if the risk is real and the evidence is out there, I want to know about it. Thanks.

        1. Thanks for the audio. Norm is one of the people I asked for studies from with no luck so far.

        2. Potatoes give me problems too, but not raw potato starch. Resistant starch is nothing like ordinary starch. I find RS to be safer than “safe starch.” Ordinary “safe starch” for me is not safe at all.

          Cooked or raw ripe plantains are also a problem for me, but not RS-rich dried raw green plantains (yes, they’re edible if dried a few days, though bland). The difference is dramatic.

          I was skeptical about RS myself until I tried it. Check out the tons of info that Otzi has provided on RS in the forum here and elsewhere. He answered every concern anyone has raised.If you decide to try it then follow the advice of many and start out slow, with small amounts.

          I didn’t hear Allison cite any studies on SIBO-related problems from RS. The audio quality was poor, so maybe I missed it.

          So still no luck, and I’ll repeat my request that I would greatly appreciate any studies from those claiming that RS aggravates or causes SIBO. The only study I’ve seen cited so far turned out to conclude the opposite – that RS actually helps SIBO, rather than worsens it. All of the claims of a SIBO-RS link that I’ve investigated so far have turned out to be unsupported rumors that are getting passed around on the Internet.

  25. Adding a lot of greens (fibrous) to your diet should help the “good” intestinal bacteria, I would think. Last night I ate 8 cups of kale (measured before cooking), and my turd was perfect this morning. (TMI?)

  26. I should add that I also eat fermented foods: my own homemade pickles, kombucha, etc. Met Sandor Katz last weekend at a workshop on fermentation: fun! He gave us all some of his miso.

  27. Mark, I would welcome your views on the so-called Superstarch contained in the Generation UCan supplement. Peter Attia has come out strongly in support, but there is a great deal of debate raging on low-carb and paleo discussion boards. As my son is a dedicate athlete I am always on the lookout for healthier ways to have him prepared for and recovering from intense physical competition. Thanks!

    1. Obviously I’m not Mark, but from the info I’ve seen, Superstarch is at least partially made up of resistant starch, possibly like the stuff in Hi-Maize, another proprietary starch.

  28. Am I the only own who finds potato starch to have a really strong potato taste? I mix my 4 TBL of the RS with strawberry-flavored kefir (and some strawberry-flavored Splenda-sweetened fruit drink) and a bit of cream, MCT oil, unsalted Kerry Gold, and coconut oil; then kinda slug it down…Not my fav drink, but acceptable… But I notice a strong potato taste. Anyone?

    1. I wonder if you are using potato flour rather than potato starch? I find even in plain water it has very little taste.

    2. Nah Elenor, I get it too. I started with the Kefir, etc. but I’ve shifted to mixing it with as little water as possible – as little as 1 oz per tablespoon and chugging that, the following that up with a chaser of the Kefir, etc.

      I don’t mind the potato flavor, but I prefer it on its own rather than messing up my other flavors.

  29. I attended a lecture on metabolic typing from a clinician who works with many patients that are metabolically damaged. He said that the macro-nutrient ratios change for some women during the course of their cycles. I forgot which part of the cycle needed more carbs. For some women, they need more carbs during part of the cycle and in other parts of the cycle they eat fewer carbs. This discussion was in the context of someone who is a mixed type, leaning towards a protein type. The majority of his patients are protein types and mixed types. He says that is because our culture’s dietary recommendations are for carb types (vegetarians and moderate meat eaters). So the people who can’t handle that many carbs and need more meat and fat tend to be sicker in our society.

  30. Perfect timing on the Resistant Starch info as I became aware recently of high blood sugar after a year of primal/VLC eating and wondering how to lower it. I have spent hours reading here and at (thanks for the link) and I’m sold. Thanks for all your research and communication on this topic tatertot. I’m glad you never gave up commenting on the MDA guest article in January! And I’m glad Mark finally chimed in with this positive entry. Here’s a suggestion for all though – please consider finding a source for organic potato starch as I did at Amazon. Bob’s Red Mill is not organic. In the introduction of Michael Pollan’s Omnivore’s Dilemma, he recounts just how poisonous non-organic potatoes are (IMO). You can read the introduction excerpt of the book free at I would cut and paste here but don’t know much about copyright laws. Gist: farm workers won’t go into a potato field for at least 5 days after chemical spraying (to fix irrigation system) as it’s too dangerous. Also, after harvest, potatoes are stored in a shed for 6 months to allow the chemical to off-gas before shipping to consumers (or potato starch processing plants?). After reading that I couldn’t eat non-organic potatoes again. Anyway, please, please, please consider finding an organic source for potato anything. And again, thanks Mark, tatertot Tim and Richard Nikoley for spreading the info on RS. I am grateful.

  31. Apparently pomegranate seeds, if ingested, are a good source of insoluble fiber.

    “One cup of pomegranate seeds contains about 7 grams of dietary fiber, most of it water-insoluble.”

    Apparently “In the Middle East and India, pomegranate seeds are often dried and ground into a powder that’s added to meat dishes” (the powder is called anardana).

    The fruit is rich in potassium, magnesium, and antioxidants. The berries explode pleasantly in the mouth while chewing them gently, and are tastier than bottled pomegranate juice from the store (unsweetened and unpasteurized).

    Fresh pomagranates take a while to open up, but I find it rather a meditative process to cut one in half and then take it apart while it’s immersed in a large bowl of water. This helps you avoid being sprayed red by accident, and the spongy parts will float up and be easy to skim off and throw away.

  32. My menstrual cycle was irregular (and often non-existent) for about 15 years – from the time of my first cycle until I switched my diet form SAD to Primal/Paleo. Doctors tried but couldn’t help other than the usual doses of progesterone or birth control pills. Some suspected PCOS although I didn’t have any of the other typical PCOS symptoms. But, about 1 month into going Primal/Paleo my cycle regulated and for the first time was on a 28-32 day cycle. It was a pleasant, unexpected, surprise. I’ve always been active, and have always eaten a lot. So, my calorie intake was never an issue. However, in true SAD form, the foundation of my diet was sugar, both in the sweets form and the bread/pasta form. My guess is that taking that stuff out leveled off my insulin for the first time in my life which normalized other hormones too. Also, my gut probably began to absorb nutrients better as well. Just wanted to share my experience to say menstrual irregularities can be caused by several issues, not just the amount of calories we take in.

  33. CITATION NEEDED: I can’t find any authoritative reference for either (1) a direct measurement of RS in retail unmodified potato starch or (2) a retail potato starch like Bob’s Red Mill (unmodified) being made from uncooked potatoes. The only official account I could find stated explicitly that Bob’s Red Mill potato starch is made from cooked potatoes:

    As far as I can tell, all assertions on FreeTheAnimal, PerfectHealthDiet, and all other paleo/primal/etc. come from a common source and single commenter, tatertot, who said that his belief was based on a science paper but did not give any references.

    Tatertot, I’m sorry if I wrong you here, but before we all run out and eat Bob’s Red Mill we need to know whether it’s actually 75% resistant starch or not! Based on my own body’s reaction to it, I have no strong reason to believe that the Bob’s Red Mill unmodified potato starch (which I was adding to my protein shake with MCT oil) was being treated by my body as anything but carbs.

    I realize that some people have said that they measured their glucose levels and these were not affected by potato starch, but a sourced direct measurement of RS content would be much more reassuring. Also the said folk need to test if their glucose levels react any differently to potato flour than to potato starch, so we’re sure what’s being tested. But mainly, I just want to know *how* we know that retail potato starch is raw resistant starch.

      1. That paper specfied the origins of everything commercially available. “Native potato starch” came from a company called Avebe in the Netherlands, which specializes in possibly exotic starches, with no obvious retail purchase method. We know that raw potatos are high in RS, but this paper doesn’t yet tell us whether Bob’s Red Mill, or any other retail starch, is made from uncooked potatos.

  34. While the calorie point about regulating menstrual cycles is definitely right – if you’ve been cutting carbs, you need to make sure they’re replaced with something else! – I don’t feel like that’s the whole story. I remember seeing a while ago on a Dear Mark a woman asking if it mattered that she and a friend increased their primal carbs on the run up to menstruating, and he linked a study suggesting that it becomes more efficient to release energy from glycogen stores than fat stores at that time (from what I remember!). For myself, I’m still not a very good primal eater, but I do normally go for fats/proteins when I’m hungry, not carbs, and I’ll get a warning a few days before my period when I suddenly find myself eating buttery pancakes! 😀

  35. I feel quite certain potatoes have helped me. for the last few years, I was getting diarrhea or loose stools (sorry for the TMI), and it kept getting more and more often. to the point of I was scared to apply for a different job because I would get urgency that comes out of nowhere, and I literally have just minutes to get to the restroom. I even went 100% gluten free in March, which did not help. I’ve went dairy free for 30 days (and remain “mostly” dairy free since then) and that didn’t help. anyways, a couple months ago I started playing around with the potato diet (nothing but plain potatoes, all day long, for weight loss). I would always bake or boil them, put them in the fridge, and usually eat them cold. I would usually do this for 2-4 days in a row. I’ve done that maybe 5 or 6 times? and I am a good 90-95% better! Perhaps it did flush out my bad bacteria? in any case, after reading this, I realized my bathroom habits have been immensely improved, I’m definitely going to keep adding in some potato days. heck, it’s fixing my “problem”, you lose weight so easy, and for some reason, it keeps me from rebounding (gaining weight, which I read is common from doing the potato diet). I can actually indulge in some fun carb binges – doritos with my mango drink, a chipotle bowl, ben and jerrys ice cream – and I don’t even gain weight any more, I just maintain. that has NEVER happened to me before! bring on the potatoes!!

  36. Does anyone have any idea if potato starch can be used in people with nightshade sensitivities? I can’t eat regular potatoes.. I assume I cannot eat potato starch, but do not know. Thank you.

  37. Any ideas on why Jimmy Moore, arguably a kingmaker within the Paleosphere, has been silent on resistant starch? Richard Nikoley (among others) seems to make a fairly compelling case for RS; I’m finding it interesting that so many in the low carb community are fighting this – or, what might even be more insidious, ignoring it entirely and hoping it will go away (like Jimmy Moore appears to be doing).


    1. Dogma. Just as CW can be an infectious disease, so can Low Carb, especially because it’s working for Jimmy. I’m not sure how long it will last, but it’s working. There are well known benefits and fallbacks to LC, many of which people seem to be overcoming by supplementing with RS. Low Thyroid, pathological insulin resistance, etc. Ketosis is really only a brain hack but long term will not keep us all in miraculous health as Jimmy thinks. So like you said, it is insidious that Low Carbers are becoming as close-minded as convential wisdom followers.

      But the jokes on them when Richard Nikoley starts gaining followers out the wazoo when they realize Fermented foods and RS are a natural brain enhancer, at least in my experience.

  38. On resistant starch. No need to buy a powder.
    Ferment instead, like sauerkraut, check out And, no I’m not affiliated, they are just awesome.

  39. I’ve battled chronic constipation my entire life, and now am dealing with, in all likelihood, SIBO/GERD/slow gastic emptying. Can’t do the LC thing, too stressful, and I end up binging by the 3rd day on everything carb. Now I’m using PS, and within the 1st week, I’m feeding logs to the city’s sewer system anyone with digestive ailments would be proud of. I’m only 3 weeks in, so I don’t know how this will affect the SIBO, but I will say, it has not worsened it. Now I’m preparing to follow Dr. BG’s 7-Steps Paleo* Gastro IQ SIBO Protocol:

    My question is how safe in non-organic potato starch? Not very, from all the literature. It’s always in any “Dirty Dozen” food list. Here’s just one link out of many on how potatoes rely heavily on cycle after cycle of pesticides, fungicides and herbicides that absorb into the flesh (so peeling ’em isn’t an option) : I’ve been using the only organic one I’ve been able to find – and this is the lowest price – the one pound bag by Frontier Herbs at Frontier couldn’t answer if it is heat-treated (modified) or not, but I’m getting all the gas and happy results one could expect from PS.

    Anyway, if TaterTot could respond as to the safety of Bob’s Redmill potato starch, and if anyone else has found a better priced organic potato flour, I would love the assistance.

  40. I made a chocolate smoothie this morning with some avocado, coconut milk, cocoa, stevia, and some sliced green plantain. Not a bad way to get some resistant starch in…. 🙂 🙂

  41. Hashimotos patients are recommended to avoid nightshades and with potatoes falling in that category is there another raw starch option that you would recommend? I’m not sure if nightshades are a no no for all autoimmune conditions but feel that for hashimotos specifically raw potato starch might not be ideal. Any thoughts or ideas?

  42. Regarding “Low to moderate amounts (an ounce or two a day) aren’t an issue…”
    Please give article names and authors proving this.