Resistant Starch Supplementation Improves Insulin Sensitivity

Part 2 of my series on the N=2 will be up early next week. In the meantime, here’s a study, with full text.

Insulin-sensitizing effects of dietary resistant starch and effects on skeletal muscle and adipose tissue metabolism

M Denise Robertson, Alex S Bickerton, A Louise Dennis, Hubert Vidal, and Keith N Frayn

From the Introduction:

“…Insoluble fibers, such as resistant starch (RS), are nonviscous and thus have no effect on glucose absorption, yet they have been shown in short-term human studies (8) to increase insulin sensitivity. Despite epidemiologic evidence linking insoluble fiber intake to a reduced incidence of type 2 diabetes (9-11), the metabolic link between chronic RS ingestion and insulin sensitivity has yet to be proven in humans.

“One possible mechanism by which dietary RS intake might modulate insulin sensitivity is through alterations in fatty acid flux. Fatty acid metabolism is a key feature in determining tissue insulin sensitivity. Abnormalities in fatty acid storage and lipolysis in insulin-sensitive tissues with increased flux from adipose to nonadipose tissues such as skeletal muscle may be a critical event in the development of insulin resistance (12). The direct effect of RS consumption on fatty acid flux is unknown beyond studies that have measured fasting triacylglycerol and cholesterol concentrations after RS intervention (7). In isolation, short-chain fatty acids (SCFAs), which are produced during colonic fermentation of RS, inhibit adipose tissue lipolysis (13), but an in vivo effect of dietary RS intake has yet to be shown.

“We showed previously that short-term (24 h) high doses of RS (60 g/d) significantly elevate postprandial insulin sensitivity, with lower circulating concentrations of both NEFAs and SCFAs (8). In the present study, we assessed the effect of a more sustainable dose of RS of 30 g/d for 4 wk to allow the assessment of longer-term metabolic adaptation to RS. By using an integrative approach to this nutritional question, we have assessed adaptation to RS intake at the gene-tissue and whole-body levels in humans.”

A few of the charts show pretty stark differences between intervention and placebo. I’ll pick Ghrelin, but you can simply check the paper to see all the other interesting things.

“Mean (±SEM) plasma ghrelin concentrations after a meal tolerance test (dashed line) in healthy subjects after a 4-wk intervention of 30 g resistant starch (RS)/d (○) compared with placebo (•). n = 10. Repeated-measures ANOVA showed a significant effect of the RS intervention (P = 0.027).”

Now, from the Discussion section:

“An interesting observation was the increase in the circulating concentration of total ghrelin after RS supplementation. This result is counterintuitive from what we know about the satiating effects of RS (35, 36) and the appetite-stimulating effects of ghrelin (37). Perhaps the systemic concentration of ghrelin is more relevant in determining its peripheral actions, independent of those induced within the hypothalamus. Elevations in plasma ghrelin have been linked to increased insulin sensitivity in numerous studies (38-40), although debate still exists as to the mechanism. It is hypothesized that the hyperinsulinemia of insulin resistance down-regulates ghrelin release and thus that elevated ghrelin is merely a consequence of the low insulin concentrations. In the present study, fasting ghrelin concentrations were significantly elevated with no significant change in fasting insulin concentrations, and thus it is doubtful that this mechanism is in place. Ghrelin has been shown to inhibit lipolysis, stimulate lipogenesis, and stimulate the expression of peroxisome proliferator activated receptor γ in vitro (41), which potentially influence insulin sensitivity in vivo. The lack of a change in fatty acid uptake into muscle in our study implies that any insulin-sensitizing effects of ghrelin are independent of those induced in adipose tissue. Ghrelin may have direct insulin-sensitizing effects on skeletal muscle. Muscle expresses the putative ghrelin receptor GHS-R1b (42), although a function for this receptor remains to be described. It is perhaps more likely that the skeletal muscle ghrelin receptor is a protein independent of either GHS-R1a or 1b (43), such as the fatty acid translocase protein CD36/FAT, as has been shown in cardiac muscle (44). If elevated plasma ghrelin concentrations are partly responsible for the insulin-sensitizing effects of RS, then the link between fermentation in the colon and ghrelin production from the stomach warrants further investigation.”

…As if life wasn’t complicated enough. You gotta love counterintuitive results like this, though (far higher Ghrelin—”the hunger hormone”—the supposed Yang to Leptin’s Yin—in the face of observed increased satiation under RS supplementation). Just goes to show that while a lot of people know a lot of pieces to the whole puzzle, nobody has even come close to putting the million piece puzzle all together.

More from the Discussion section:

“…In an earlier short-term study (60 g RS for 24 h), we found RS intake to increase insulin sensitivity at the whole-body level and to increase hepatic insulin clearance, a finding that was corroborated in the present study when RS was included in the diet at more physiologic levels (30 g RS/d for 4 wk). We have now shown insulin sensitization at the whole-body level assessed by both the hyperinsulinemic-euglycemic clamp and the MTT methods. In addition, we showed a reduction in adipose tissue lipolysis and an increase in the insulin sensitivity of skeletal muscle glucose clearance. These effects of RS may be due to changes in the peripheral metabolism of SCFAs or in the secretion of ghrelin.”


“In conclusion, RS intake increases insulin sensitivity in non-insulin-resistant subjects by changing both adipose tissue and skeletal muscle metabolism. This is potentially due to elevations in the systemic concentrations of both ghrelin and SCFAs. RS intake at this dose (30 g/d) was well tolerated and thus could have beneficial effects for the treatment of insulin-resistant persons or those with type 2 diabetes. This would require further investigation.”

In my own Conclusion, let’s jump back up to the Results section:

“There was no significant difference in reported food intake between the 2 supplementation periods and no subsequent change in either body weight or BMI. There was a small but significant increase in lean body mass (P = 0.003) averaging 1.1 kg (0.6–1.6 kg) over the 4-wk period of RS supplementation”

Translation: if weight or BMI didn’t change, but lean mass increased to the tune of 2.2 pounds over 4 weeks, then body fat had to have decreased. Now, run that out to several years worth of supplementing resistant starch. A few tablespoons of cheap Bob’s Red Mill Potato Starch just might be your slow, body comp improvement Ace in the Hole.

Leave it to the guy at SupVersity to be on the trail: Fast Absorbed High Molecular Weight Resistant Starches Make a Comeback in Diabetic Formula: Are RS-4 (WM-HDP) Based Products An Ideal Meal Replacement for Diabetics?

He’s talking about more expensive, engineered stuff. Just use the Bob’s Red Mill Potato Starch or get some plantain flour; or tapioca starch will do the trick, too. I like to mix & match, plus eat leftovers cold, including properly prepared beans.

Trust me: this is only going to get worse and worse for LC Starchophobes, who make no critical distinction based on their religious reading of a 6-letter word. …Until they come clean and begin to display some honesty, which I predict will happen, eventually. However, they will have to admit they have been wrong for decades about a lot, which they have been. They should also admit that they’ve been huck-huck obstinate, arrogant and dismissive about it, too. This stuff has been out there for a long time. Completely dismissed, because of a word: STARCH!!!

And so, the reputations of LC advocates have basically taken a big hit with me now, especially in light of out-of-hand dismissals, which I suspect were simply just-so attempts to discount any relevance and benefit, in order to smear good science in favor of catechism and doctrine. I always call it how I see it, and that’s how I see it. Very difficult for me to trust that they are truly looking at stuff with open hearts, minds, and eyes.

But I’m a sucker for redemption, so let’s get on with it.

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  1. Resistant Starches - Page 21 | Mark's Daily Apple Health and Fitness Forum page 21 on September 13, 2013 at 10:15

    […] article on RS and insulin sensitivity. Reply With […]

  2. Andy Benkert on September 13, 2013 at 11:01

    What kind of beans do you recommend, and how would you prepare them? I’m using the potato starch, but would like to give beans a try, too. Can’t say for certain it’s been helping my glucose levels, but not hurting as far as I can tell.


    • Richard Nikoley on September 13, 2013 at 12:09


      Any beans. I just mix them up. There are differences. Black beans appear to be the most nutritious. I have some soaking right now. Last batch was pintos. Before that, black, garbanzo and kidney for a 3-bean salad. I like eating them cold from the fridge, which has a higher RS value than reheating. I’ve acquired the “taste.”

      It mystifies why why people just want to be told what to do. Stop it, Andy. Cheeses & Pleases.

  3. Sue on September 13, 2013 at 11:07

    So regular old potatoes are the resistant starch?

    • Richard Nikoley on September 13, 2013 at 12:06


      No, but do us a favor and run down the rabbit holes yourself. Search Resistant Starch in the search function. Read, including comments. We’ve all answered this question going on a hundred times and I’m deleting all such questions summarily from here on out.

  4. BigRob on September 13, 2013 at 11:36

    I’d say gaining 2.4 lbs of muscle and losing an associated amount of body fat is pretty darn significant. Not to mention that the metabolism will increase in the individual that gained that muscle.

    Pretty darn cool stuff.

  5. Jeff on September 13, 2013 at 12:21

    As always, yours is a voice of reason among the blind followers of dogma…. I shall now become your disciple….(tic)

  6. Richard Nikoley on September 13, 2013 at 12:34

    Don’t do it, Jeff. I will disappoint you.

  7. John on September 13, 2013 at 12:38

    Sounding like RS in general and PS in specific would be a great addition to any period of caloric restriction… up to and including a fast. And it wouldn’t really nullify a fast, since it’s not really “you” that’s eating it, would it?

  8. Richard Nikoley on September 13, 2013 at 12:58


    That’s my general take but in the more general, I think the gut needs fasting too.

  9. Tim on September 13, 2013 at 12:59

    I’m already on the RS bandwagon — the science and the N+1’s are enough for me to give it a go. But the one piece I feel has been missing is the ancestral aspect, which has always been an important part of this whole deal.

    Maybe I missed it, but, has anyone ever shown that getting 20-30+ grams of RS daily was the norm for pre-industrial societies? What were they eating, and how were they preparing it, to get those quantities? This becomes especially trickier to see in a hunter-gatherer/paleolithic context, where rice and beans weren’t a part of the picture. And I also have a hard time believing that consumption of green plantains and bananas (in the limited areas where they were even available) was a common ancestral practice (because, well, why would you?).

  10. Andy Benkert on September 13, 2013 at 12:59

    Richard, not looking to be “told what to do.” Looking for recommendations, as I’ve read all the posts on RS and beans, and read a lot of other info “out there” about beans in particular, and wasn’t quite able to discern if there were types that would be best for someone like me with T2 diabetes. The dogma on beans from the LC perspective is quite the opposite from what you are presenting, obviously. So confusion is not tantamount to wanting to be hand-held. Just looking for honest information and recommendations from those who already have some experience. Why recreate the wheel when I can go to Big O tires and buy them?

    • Richard Nikoley on September 13, 2013 at 13:04

      @Andy. Get some potato starch (unmodified, like Bob’s) plop a T in things up to 4-5 times a day and give it a whirl. Nobody here is your doctor. Nobody, actually, is your doctor. You’re your doctor. Others just play the role.

      There’s a recommendation. Now, get out on your own, if you can manage.

  11. Richard Nikoley on September 13, 2013 at 13:08

    …And Andy. Get a taste for cold beans from the fridge. I love them best that way, now. Then again, I cook fucking killer beans (a bit of bacon—perhaps 1 slice per 2 cups—helps).

  12. Richard Nikoley on September 13, 2013 at 13:11


    has anyone ever shown that getting 20-30+ grams of RS daily was the norm for pre-industrial societies?

    Yes. From raw stuff, including starches. Look at the coprolite evidence. How many modern people have significant amounts of pollen in their stool, for example. Pollen is huge in RS. Go to youtube and search for cattail pollen. Just one example.

    In short yes. Even the SAD is far higher in RS than Paleo, which is less than typical primitives.

  13. Andy Benkert on September 13, 2013 at 13:32

    As I mentioned in my original query, I am taking potato starch on pretty much a daily basis (2-3 tbsps), and can’t say for sure that it is having a positive affect on my glucose numbers. But I’m continuing with it as I believe, from what I’ve read, that there are other benefits beyond glucose control.

    I was just interested in your, or others’, recommendations on type of beans and any special cooking/prep methods. And roger on eating them cold, seems like that is key for any RS ingestion from what I have gleaned from your posts on the topic.

    And yes, I can manage on my own. Have done a pretty good job of it so far bringing down an initial A1C of 15.4 to 6 in less than 6 months. Just looking for some advice. Though not the drama that came with it.

  14. pzo on September 13, 2013 at 14:44

    @Andy: Do your research, is what Richard is saying. I will, too. But I’ll give you some hints. There’s little real difference from the tiny lentil to big lima beans. Not enough to waste any angst on.

    For regular mid-size beans like pinto, black, and navy, soak for 24 hours room temperature, change once very early on, and once more maybe half way through. It’s all flexible, don’t seat it. Cooking, after a 24 hour soak, will take about 40-45 minutes. Don’t over cook.

    I’ve not done either lentils nor limas, so I can’t advise there. Since lentils cook from dry in about 45 minutes, i would test constantly while cooking after a long soak.

  15. pzo on September 13, 2013 at 14:52

    Besides cost, there is another great reason to cook your own beans. Sodium/potassium amounts and ratios.

    Canned black beans, .5 cup, 460mg sodium, 360 potassium. Not good. Cooked from dry, no salt, less than a milligram of sodium! 305mg potassium.

    As an aside, the only natural food that is high in sodium is eggs! About 50-50, close enough. But every single other natural food has potassium outweighing sodum by at least 10 to 1, often hundreds to one.

  16. Andy Benkert on September 13, 2013 at 15:02

    @pzo – Thanks for the hints and info, very much appreciated. I have done a fair amount of research, and seemed to get conflicting info which is why I posted the question here to see if I could take advantage of others’ experience. Now off to the store, then the kitchen. :-)

  17. bornagain on September 13, 2013 at 15:13

    I wonder if some the rapid initial weight loss low carbohydrate neophytes all rave about is actually due the several pounds of gut microbes dying and falling out their arse?

  18. Paleophil on September 13, 2013 at 15:22

    Richard wrote: “Even the SAD is far higher in RS than Paleo”

    From now on I think I’ll refer to the bogus forms of “Paleo” that prohibit healthful foods that are very much like the foods that our Paleolithic ancestors actually ate (such as resistant-starch-rich foods like African herb tubers, legume tubers and other underground storage organs, and groundnuts) as “Faileo”. True Paleo does not prohibit RS-rich foods just because RS has “starch” in the name.

  19. Richard Nikoley on September 13, 2013 at 15:47


    Kudos for enduring my gauntlet unperturbed. Please stick around then. Feel free to toss shit my way when you see fit.

  20. bornagain on September 13, 2013 at 15:51

    @Richard. Will you be updating your ebook with RS info or writing a new ebook perhaps?

  21. Paleophil on September 14, 2013 at 06:20

    Mark Sisson has OK’d resistant starch foods like raw plantains and green bananas and other prebiotics as Primal here and here

  22. Richard Nikoley on September 13, 2013 at 16:32


    All up in the air. Don’t know. Chewing.

  23. marie on September 13, 2013 at 18:59

    Andy Benkert,
    I can’t see why Richard made you suffer the gauntlet, so I’m thinking it’s time for ‘a spanking’ :D

    it’s been months no one’s posted this. Quelle negligence! Pour ma part, tu m’excuser mon cher?

  24. Andy Benkert on September 13, 2013 at 19:16

    @Richard – thanks and will do.

    @Marie – all I had to see was the “Castle Anthrax” and a big smile came across my face. One of my fav movies! Thanks for posting that. :-)

  25. marie on September 13, 2013 at 19:21

    Andy, ’twas my pleasure ;)

  26. La Frite on September 14, 2013 at 02:02

    It’s the second time in a few months I try coconut milk mixed with RS (first was potato starch, last was FiberFine based on Hi-Maize stuff). Result -> …. explosive episode of diarrhea …
    Coconut milk + RS is no longer on the menu here. I do have RS randomly via green bananas, FiberFine, cold tatoes, and use xylitol as my sweetener (cannot stand white sugar, my teeth hate it). I eat garlics, onions, leeks, etc, and I have no digestive issues. But something in coconut does not agree with me …
    That was not to tell every one he/she should avoid it but more humbly a little bit of data that could interest anyone (or no one :) )

    One thing from the article: it says that lipolysis is reduced so that muscles take glucose more efficiently (if I understood correctly) … so why the leaner results in the 4 week experiment ? Doesn’t lipolysis mean fat breakdown into FFAs ? aren’t those FFAs a source of energy for organs and muscles in absence of glucose ? I find it all odd …

  27. yien on September 14, 2013 at 02:31

    “has anyone ever shown that getting 20-30+ grams of RS daily was the norm for pre-industrial societies? ”

    RS and grok – is worth a post? [since you won’t get the sycophants at MDA, and others, to come over until this is clearly shown….]


    The medicinal uses of poi –

    Tatertot “Plantains/bananas were dried and stored throughout Africa, potatoes were dried and stored throughout S. America, corn was dried and stored throughout N. America. The inuits had ‘Eskimo Potatoes’ which were dried and stored throughout the Arctic.”

    +add drying and storing cassava

    commentator Brad – “As Flores spoke, peasants prepared chuno, or dehydrated and chilled potatoes, and tilled the soil with ox-driven plows. Donkeys brayed and sheep and cattle grazed.”

    Coprolite studies –

  28. kayumochi on September 14, 2013 at 07:27

    Anyone note that the raw meat advocate Aajonus Vonderplanitz died recently?

  29. Richard Nikoley on September 14, 2013 at 08:07

    Had not heard about that. Total kook to be sure, but it’s sometimes good to have those guys around pushing things. Too bad he didn’t get a chance to demonstrate how his diet might work for him (his death appears to be caused by injuries sustained from a collapsed 2-story balcony). Same kinda deal as Stanley “The Bear” Owsley a few years back. Car accident.

  30. kayumochi on September 14, 2013 at 12:12

    The Wikipedia entry for Vonderplanitz claims he developed the “Primal Diet.”

  31. Richard Nikoley on September 14, 2013 at 13:42

    Yea, well, both Paleo and Primal can’t be trademarked and clearly defended. Mark would have a decent chance with Primal BLUEPRINT.

  32. Paleophil on September 14, 2013 at 14:20

    Mark had to settle for trademarking “Primal Blueprint” because Aajonus had already trademarked “Primal Diet.” Loren Cordain trademarked “The Paleo Diet.” They are all showing as registered trademarks at One podcaster even said he was told to stop calling his diet “the Paleo diet” (though I think he could get away with it if he just changed “the Paleo diet” to “a Paleo diet,” since “the” is in the trademarked phrase).

  33. pzo on September 14, 2013 at 15:51

    Mark came out ahead. “Primal Blueprint” is SO much more about life and lifestyle than just diet. As life is.

  34. Richard Nikoley on September 14, 2013 at 16:15


    I agree. I think Mark has a very defensible brand/trademark. He’s very smart, very forward looking. I salute. Should anything ever come to a dispute, patent/trademark judges aren’t dumb and some common law sneaks in in principle if nothing else (ie, a sense of morality). Who actually worked on it and built it, instead of just filing paperwork hoping to get a buyout or license fee?

  35. Weekly Roundup #72 on September 14, 2013 at 19:53

    […] Does resistant starch increase insulin sensitivity? Richard Nikoley breaks down a study that answers that question. […]

  36. doogiehowsermd on September 14, 2013 at 23:52

    ditto re: Mark Sisson. The guy is a business genius and just an all round nice guy. He genuinely cares about what he does and I hope he feels rewarded for his efforts.

  37. Linda on September 14, 2013 at 23:54

    I was just wondering at what temperature the rs in potato starch is reducing? Is it fine as long as it’s not thickening or has it to be cold?

  38. Paleophil on September 15, 2013 at 16:07

    Ditto on the positive comments re: Mark Sisson. Couldn’t put it much better myself.

  39. Mart on September 15, 2013 at 17:20

    re: cold beans. When I cook brats the fond that they leave in the pan is – I think – a sticky mess of collagen and stuff that has rendered out. I let that soak in water for awhile then reheat it, adding spices such a turmeric, paprika, black pepper. It mostly dissolves into a gravy/sauce which you can use to add a powerhouse of flavor to anything – including those cold beans. I mix it in right when they have finished cooking.

  40. Mart on September 15, 2013 at 19:19

    re: cold beans – I add flavor to them thusly: Whenever I cook brats the fond remaining in the pan is – I think – collagen etc that has rendered out. I add water to that, plus spices like turmeric, paprika, black pepper. The sticky fond mostly dissolves as you reheat and stir, and you end up with a gravy/sauce that is a powerhouse of flavor. It can be used for many things, and one of those is to stir it into the beans right when they’ve finished cooking. Makes them far better cold eats.

  41. […] In other news, because it's my wife's birthday today and so I don't want to spend much time on the blog; but, one commenter asks about Grok Eating resistant starch. […]

  42. Wenchypoo on September 19, 2013 at 03:13

    For PZO concerning canned beans and the sodium/potassium ratio:

    Eden small red beans:

    Eden black beans (low sodium):

    Eden makes a whole line of low-sodium beans–look for them in health food stores. Yes, cooking them yourself IS cheaper, but for those who crave convenience…

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