Robert Lustig says fiber is essential


So I’ve started reading Robert Lustig’s blog. And my first thought is that what he writes makes a lot of sense. His approach to the obesity epidemic appears entirely sensible. He has spent 25 years investigating the causes and treatments of chronic disease, and he sums up his research career in three simple precepts (in his own written words):

  1. It’s the insulin, stupid.
  2. It’s the sugar, stupid.
  3. It’s the lack of fiber, stupid.

Robert Lustig wholeheartedly believes fiber is essential for health. Whereas he tells people not to consume processed foods, and has openly declared war on the food industry because of its penchant for putting sugar into everything, he also believes we should eat a varied diet. He believes we should eat intact whole grains, vegetables, nuts, beans, fruit and dairy.

My own experience has been that when I decided to quit the carnivore WOE and go back to basics, to keto, which involved adding back in fiber-rich vegetables and nuts, my body thanked me, and now, instead of dragging my feet across a room, I am finding myself running up the stairs again, and my digestive system is back to normal. I will also be incorporating other sources of fiber such as fruit, say avocado and berries.

My keto allowance of vegetables today.

And a little later my fatty meats (I’ll probably have the last 2 pork chops later today. My lunch earlier on was mackarel).

To not see carbs as the enemy, I think Robert Lustig’s point is here, and to differentiate between rubbish processed food which generate diseases, and nourishing whole foods. Carbs, I have come to believe, are not the enemy. The way our minds perceive them, are swayed by science, how we have become rather rubbish at listening to our bodies, is a more likely culprit. And the lack of knowledge the public has about what is healthy, and what isn’t, and whether the difference matters.

Oh well, just thought I’d share my thoughts. You are welcome to share yours. I believe it is important to stay open-minded as we human beings are so prone to confirmation bias, and not just focus on studies, articles, people we agree with. It is also very important to see the matter from different point of views, in order to see the bigger picture, or at least feel well enough informed.


I firmly believe he is wrong cause again, the body requires fat and protein only for total physical survival and to thrive…it requires not one plant carb ever for any survival. "Animal fat’ and protein clearly is trumps to supply the body with ALL necessary nutrients/vits/mins for surivial of the human body. Plant proteins can never ever never ever do this!!! Not from one plant source! So to me that fiber is a must is just BS and ‘hey something that many do believe’ and will rant til the end of time on that one :slight_smile: :slight_smile: but I say ‘BUNK’ and of course the gurus and Drs spouting all this are out there saying, lil’ old me is just living life without fiber intake and got all the damn results and healing and health I could ask for, what do I know HAHA especially when I base my lifestyle on actual proven scientific proof? oh well----can’t change what is out there, one thing I can do is live my best life OFF fiber and thrive. 6 yrs no fiber, ain’t dead yet and best ‘guts I ever known’ thru my whole life :slight_smile:

Someone will always spout whatever out there in ‘healthy menu lifestyle’ plans. at some point just eat how you feel directed, that is the only way forward for many. stop reading, start eating the ‘good stuff’ and put that N-1 into real practice :slight_smile:

(Bacon is a many-splendoured thing) #3

While I respect Dr. Lustig, it is necessary to take his remarks in context. He does not recommend eating a ketogenic diet. While he is not opposed to such a diet, he does not approve of it, either. What he recommends is a high-carb diet involving whole fruits and vegetables, and in that context, fibre is probably necessary.

On a ketogenic diet, however, as Dr. Jason Fung’s aphorism goes, “Carbohydrate is poison and fibre is the antidote. But if you’re not eating the poison, you don’t need the antidote.” Like all good phrases, this is not entirely true, and we have a number of forum members who find they still need fibre in their diet. However, we have just as many forum members who find that, on a keto diet, any fibre they eat is actively bad for them. It irritates their bowel, exacerbates their Crohn’s disease, and so forth.

As Dr. Stephen Phinney points out, the main benefit of fibre is supposed to be the butyrate produced from it by our intestinal bacteria. However, one of the main ketone bodies produced on a ketogenic diet is β-hydroxybutyrate, which is just as good for the intestine as butyrate, if not better. So the main benefit of fibre is provided on a ketogenic diet, whether we eat fibre or not.


Hi Fangs, I don’t think it’s set in stone, that either everyone on the planet requires fiber, or that everyone on the planet has no need of any fiber. I believe that, just like with so many things in life, it comes down to the individual, and there are so many factors and variables. I do believe some people truly need fiber to thrive, and that I am one of them. But, although I’ve shared here some of Robert Lustig’s beliefs, I do not believe his teaching will benefit everyone. For that matter, I do not believe Dr. Paul Mason or Dr. Paul Saladino’s teachings will benefit everyone. So, although I always think it’s beneficial to keep an open mind and be willing to take in different point of views, there must be another, more important component in the equation, and that is the body. It is vital, I believe, to listen to one’s body every step of the way, and there’s no shame in adjusting one’s WOE if the body is signalling it wants that change, just like there is no medal for staying on plan, but the reward and outcome in either case is that we are doing what we can for our health, through listening to our bodies.

(Chuck) #5

If we listen to any one person or research we are all going to go down the wrong path. We must do our research, by both reading, and doing our own experiments. Then in our own body find what works, and accept the fact you will have to make adjustments over time as your body changes. Most research is paid for by a person, company or foundation that has a result already in mind. That is why it is so important to do your research, and experiment yourself to find your own best solution.


Hi Paul. I suppose I believe in perhaps … a middle way? As in keto, with vegetables, nuts, berries, fruit in the form of avocados, though not the same carbs everyday. So a small plate of some berries and nuts one day, a plate of some vegetables another day. I keep it all in fairly small quantities and yet I experience a benefit. I have resolved my constipation issues whilst still remaining keto. As to Dr. Jason Fung’s statement regarding fiber as the antidote, why then, do people who adhere to a ketogenic carb allowance prioritise vegetables, why is it beneficial to them? Unless one has actually tried carnivore oneself, I wouldn’t rely too much on Dr. Jason Fung’s quote to provide the only answer. It may be true in some cases, but it may very well also not be true in all cases.


Hi Chuck, I agree. With science there is the problem, both of confirmation bias and corruption. Yet doing our own research also puts us at danger of facing those same two obstacles: confirmation bias, and fraudulent information. So it really comes down to us as individuals, to experimenting on ourselves and making adjustments along the path if need be. And here is my takeaway: necessary adjustments to our health path are not a problem. So long as we manage to stay on the ketogenic path, continue to enjoy our lives and thrive, continue to stay open-minded and intuitive, we will continue to do our health and our bodies good.

(Chuck) #8

My rules are simple, no wheat and oats, rice and potatoes are acceptable in very limited amounts for special meals. Fruit also in limited amounts at special meals. But I stay away from bananas. My goal is more low carb than keto, I do stay mostly and on average at or below 50 total carbs per day. One of my stables that isn’t on the keto diet is prunes, I have 3 every day. My ratio is about 60% fat, less than 10% carbs, the rest protein.

(Bacon is a many-splendoured thing) #9

Personally, I find that I only get constipated when I don’t get enough salt. Fat also helps, but salt is essential.

Apparently, when Carl and Richard founded the Facebook group that preceded these forums, they really wanted to recommend a 0-carb diet, but feared that would put people off, and they didn’t want to put obstacles in the way of people’s metabolic healing. (They had both reversed their Type II diabetes and wanted to provide the same benefit to others.)

And as far as prioritising vegetables goes, I don’t prioritise them, and I suspect many other forum members don’t, either. I follow Prof. Bikman’s advice to “control carbohydrates, prioritise protein, and fill in with fat,” which works pretty well for me.


Hi Chuck. When I think about fruit I think about avocados, keto friendly berries, cherry tomatoes, cucumber, bell peppers, etc. I don’t really think about the sweeter kind due to their high fructose content. I am keeping my carb allowance below the keto friendly limit 20 grams, but that is still an allowance that will allow for quite a few healthy whole foods, that could be alternated on the different days so as not to exceed the limit. For me, staying in ketosis is a goal, and also fat adaptation. But I believe many who don’t require to be in ketosis will benefit greatly from a low-carb WOE. It all comes down to individual circumstances and what works for you. I also believe it is important to enjoy the WOE, and I feel lucky in that I do, and have no carb addiction. I don’t miss bread and other bakery goods at all.


But do you eat any carbohydrates at all? Would you say you are keto or carnivore? I certainly believe in the benefit of controlling one’s carb intake, I just don’t believe a 0 carb allowance is necessarily healthy for everyone. Some might do very well, some might not, it’s highly individual.


Each to their own but we should know the few facts like carbs aren’t essential at all. Some people work better with them, sure, some even need a ton! But normally the human body manages without any and even might strongly prefer that.

I totally listen to my body and it says all plant carbs suck :slight_smile: (I can handle them all in small enough amounts. Never had any problems except the carb content.) And fibers aren’t needed at all.
My body NEVER thanks me if I add plants at all. It handles them pretty well, I am not used to feeling sick even if I have a high-carb day (as long as I avoided carbs for a while before, at least) but I always, always feel some change and it’s not for the better.

If you need carbs, eat them, fine. And it’s good indeed to know which to eat and which to avoid. I don’t avoid anything, I eat whatever I fancy but I can do it (sometimes. overdoing it isn’t nice). And I am aware what I am doing. Added carbs in very processed things is the last thing I eat as that is the worst and only good enough quality things there as the bad quality stuff knock me out, along with my high-carber SO. Dense sugars are the next (fruits, honey or other sugars? don’t matter much, my body considers them all simple sugars as they are, it doesn’t feel any better than some processed sugary thing, at least the latter brings a ton of fat and some protein as well. of course processed things are very different, I don’t really have problems with the ones I eat but some has some stupid ingredients. but simple sugar is already one of the worst, even in natural food), starches are better and animal sugars aren’t problematic at all. Fibers are neutral, it doesn’t matter how much I consume of it, apparently. It never changed a thing.

By the way, food industry has some surprising items :smiley: I met one today. We have a very very traditional sweet biscuit here, it was around in the previous era when we had nothing from the West too. I saw a sugar free (and fiber rich) version of it today and what they replaced sugar with? NOTHING :smiley: It’s completely unsweetened. Wow. Just my favorite attitude when I change things in a recipe…

I need such refreshing things, I am among the ones who, with reason, have problems with food industry. Fortunately sugar isn’t in everything, I eat plenty of sugar free processed stuff (I see zero problem with them, honestly, my diet would be less healthy without them too. of course I choose well what processed stuff I use) - or even if they have some, it’s negligible. I have a fancy pâté now, label says it has 0.3g carbs and it’s apparently mostly spice and a tiny starch. And there is sugar in the ingredient list, it just must be below 0.1g… Why do they put it in I can’t imagine :smiley: No one can feel the difference… I don’t even feel 0.5% sugar in processed meats and consider that negligible too but if I can buy an added sugar free one, I do that. Fortunately that is easy for most of my processed items.

(Chuck) #13

I grew up on a working farm, we grew cotton, wheat, oats, cattle, pigs, we had an orchard with peaches, plums, figs, and a huge vegetable garden. We ate what we grew fresh, preserved. Salt pork, and smokehouse meats were always available, as well as jerky and dried fruit and vegetables. I was 21 and in Navy boots camp before eating processed foods. I gained almost 50 pounds in the eleven weeks of boot camp and it was the cause to my weight issues for the rest of my life. The way I eat now is a throwback to my childhood and teens.


Indeed. I often think about it when someone wants to push plants on me. I never eat something for health ONLY, I need to want it. I don’t want plants most of the time and sometimes I am very very much against them. It takes away room from my better food and I can’t eat as much meat, fat, egg and dairy as I wish… If I suddenly needed 1000 kcal more, I would add more carni food, not plants. (Sometimes I do desire some plants and I eat them. Definitely not regularly and if regularly, just a tiny bit.)

There are carnivores enjoying their food and long term, not like me who keeps going off (and coming back very quickly as it feels worse but had to be done for some reason. I almost never have regrets). And they prove that fiber ISN’T essential in general. If one needs it, that’s an individual thing, not a general human requirement. We all need protein and fat, various micronutrients - but no carbs or plants. Or animal products, actually as one can survive without them too. It may be trickier but one can get everything from other sources somehow. I mean theoretically and in many, many cases practically, obviously not everyone would survive let alone thrive like that. But we are very good omnivores, we can survive on very different diets.

I still don’t get the emphasis on berries (and I always think about the facts like banana is a true berry while many -berries aren’t… never fails to entertain me) but each to their own, again. I definitely wouldn’t ever limit myself like that. It’s more like carbs per satisfying portion. I never had more than a few carbs for that on vegetarian keto so I almost only went for the most joy in that amount, usually raspberry and banana won but there are so many other good options like sour cherry though they are super sweet now and quince and lemon are better. But I eat any fruit I desire and happen to have, obviously :slight_smile: They don’t cause any problem as I never eat much of them. But forced restriction would harm me. (I rarely actually desire fruits since I tried carnivore but when I have fresh fruit, it starts to wear me down mentally and I don’t see the point to resist anyway.)

Of course I write about me and fruits again, I NEVER can resist when the topic comes up… :frowning: And it’s still months until my first fruits so I talk about them instead of eating them. That happens too but in negligible amounts, far from my old 1-3 grams a day :wink:

(Megan) #15

For people needing to keep their carbs very low, above ground veg, esp the green leafy ones, make the most sense to eat b/c they are very low carb. I’d take a guess and say that’s why some people doing very low carb keto eat them, tho some may eat them b/c they also believe they are beneficial to them.

I’d never say fiber isn’t helpful for some people, but it can take a good chunk of time for some people to fully adapt to zero fiber and discover they are fine without it.

Bottom line tho is everyone can eat whatever the hell they want to eat. Who cares /shrug


That sounds wonderful Chuck, you were lucky to grow up in those circumstances. With the best of the very best of whole foods because they were from your own farm. I certainly can appreciate you wanting to go back to such a lifestyle, which you’ve experienced works for you, when you went down the path of processed foods, and the way it affected you. All we can do is follow both common sense, our own intuition, and some science, and keep moving, thriving on our path.


Hi Megan, I suppose nutrition as a topic just interests me, as well as the science, however confounding, around it. But I am aware of the traps of confirmatiom bias and corruption, aka studies bought and paid for by the food industry. As to it taking longer for some to walk through that adaptation that is often mentioned in the carnivore community, as a stay at home mum I haven’t got that time, I need to be at my very best, and adding back in a few carbs for me, basically going back to basics, back to keto, has provided me with more energy. In the end of the day we always do us, we do what works for us as individuals because only we can feel our own bodies, and yet there’s nothing wrong with learning from one another as a community either. So long as we keep discussion open, and various views are both represented and welcome, because one WOE does not fit all.

(Chuck) #18

My grandmother always said to longer you cook anything the more of the nutritional value you lose. My grandfather was the one to make the jerky, grandma would shake her head and say that grandpa was burning off all the nutritional value. I don’t know that for sure because I love good homemade jerky.

(Doug) #19

Holy Crow! That’s a fast weight gain. (Wish I could do that in reverse. :stuck_out_tongue_winking_eye:)

(Joey) #20

Back to Lustig for a moment, yeah, I don’t agree with every idea he pushes.

Then again, I’ve yet to meet anyone with whom I agree on every idea they’re pushing. :wink:

Now there’s an idea worth pondering!

Science is about finding repeated, controlled circumstances that produce the same identifiable result.

That’s not a good description for much of what’s involved with human nutrition…

  • None of us are identical subjects at any moment in time.
  • The lag between cause and effect can be decades.
  • Both genetics and environment (epigenetics) play a major role.
  • And so, countless confounding factors muddy the works.

Since biology is about average population responses, and none of us is precisely average in the moment, our best nutritional insights are merely soft approximations at any point in time.

So yes, listening to our own bodies is an essential component of good health.

Unfortunately, the time lag between good health habits and a good health outcome is further compounded by our response to the challenge of “what feels good” inherent in our choices.

In short, we’re stuck here in our respective individualized human condition. Live and learn. :vulcan_salute: