[HN Gopher] Got food cravings? What's living in your gut may be ... ___________________________________________________________________ Got food cravings? What's living in your gut may be responsible Author : gmays Score : 141 points Date : 2022-04-22 16:02 UTC (6 hours ago) (HTM) web link (www.pitt.edu) (TXT) w3m dump (www.pitt.edu) | smallerfish wrote: | Does anybody know of good research which shows how long it takes | the microbiome to adjust if you significantly change diet? New | diets can be hard to stick with initially, and it seems like the | gut's "needs" may be a real cause of this. | hirundo wrote: | I'm a long-time serial dieter who has radically changed my diet | on several occasions now, from SAD to vegitarian to SAD to | vegan to SAD to raw vegan to SAD to FODMAP to SAD to McDougall | high carb to paleo low carb to meat-centered to (currently) | carnivore. (Among others.) | | Each time (moving to non-SAD) it takes around six months before | I stop naturally losing weight and either stabilize (on | carnivore) or start heading back up (on everything else). I | attribute this mostly to the microbiome, so by my own N=1 | experiments, I'd say about six months. | kshacker wrote: | As a fellow failed dieter, just trying to find something that | will work for me ... | | So you switch diets because you stabilize and want more | weight loss, OR because they stop working? Curious to hear | about the switch. | | My personal preference is sugar-free. Successful for 2 years | from 2016-2018, and now trying low-sugar (not no sugar) since | January 2022, and reasonably successful although not much | (just 6 lbs about 3%) to show for it. | hirundo wrote: | I was a failed dieter from age 7 to 57. It took me that | long to figure out that this body works best on animal | products. I was never a particular meat eater and had to be | forced to try it by an inability to move my bowels on | anything else. But it has reduced and stabilized my weight | like nothing else has, while all but eliminating my | cravings for SAD food. I really like eating this way now, | and get as much or more pleasure from food than ever. | | When I switched it was in despair over failure. They all | (but the last) stopped working, though I continued to | follow them religiously. For years I was an obsessive food | diarist, and have books full of logs on what I ate, with | charts showing how my weight gradually stabilized well | before goal, and started going up again. This followed the | trend of my appetite. When I switch diets my appetite goes | down, and it recovers gradually over that half-year. | | I think going sugar-free is a great move, but from sources | like https://high-fat-nutrition.blogspot.com/ have come to | think that avoiding seed-oils is even more important, over | a span of decades. | mirceal wrote: | imagine all the microbiome meetings and all the unhappy | little fellas having to go through a reorg every 6 months. :) | mech422 wrote: | LOL - I snorted ... | | Maybe they can 'pivot' in a new direction :-) | mirceal wrote: | need to receive a VC cash infusion immediately to prevent | hitting the end of their cash runway! | octokatt wrote: | This was a good enough question I started researching. TL;DR: | Your microbiome adapts quickly, but you don't get to see the | full effects for weeks to months. | | Turns out, your microbiome will shift significantly within a | few days of changing your diet [0]. A more recent study showed | that increasing raw vegetables in your diet significantly | changed microbiome at about the same speed [1]. | | However, because the _effects_ of a healthy microbiome are | things like better vitamin reception and disease prevention [2] | [3], it can take months to see the effects of something like | better B12 can take weeks to see [4]. Disease prevention of | metabolic diseases takes years to see fully. | | [0] https://www.scientificamerican.com/article/the-guts- | microbio... [1] | https://news.harvard.edu/gazette/story/2019/10/study-finds-g... | [2] | https://en.wikipedia.org/wiki/Human_microbiome#Disease_and_d... | [3] | https://depts.washington.edu/ceeh/downloads/FF_Microbiome.pd... | [4] https://www.nhs.uk/medicines/cyanocobalamin/ | virtuallynathan wrote: | It's very quick: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3957428/ | narrator wrote: | I'm on day 10 of a 14 day water fast. The hunger was very bad for | about the first 7 days and now its been nothing. The idea of | eating is interesting to me, but the visceral hunger constantly | reminding me to eat isn't there anymore. Long term fasting is | great like that. | herpderperator wrote: | Are you really not eating for 2 weeks? | narrator wrote: | Yes, really. Some people do it for 30 days or more if they | have a very large amount of weight to lose. You have to take | electrolytes (potassium, sodium, magnesium), and it should | never be done if underweight. I started getting seriously | into fasting when I asked all the people I met at longevity | conferences who looked extremely good for their age what | practices they used. The ones who looked the best for their | age were longer-term fasters. | | Fun fact, the longest fast was 382 days[1]. The guy started | at 456 lbs and ended up at 180 lbs. | | [1]https://en.m.wikipedia.org/wiki/Angus_Barbieri%27s_fast | lukewrites wrote: | I'd love to learn more about the longevity conferences | you've attended, if you don't mind. | filoleg wrote: | I am very curious about a couple of things regarding that | experience, so I hope you dont mind if I ask a question. I | want to preface it by saying that I am not trying to | dismiss this pracice as inherently dangerous or bad | (because I frankly have no idea). | | While with 14 days of it probably not being a concern in | that aspect, but do people who do it for much longer | periods (100+ days, or maybe even less would qualify) not | have any atrophy-related issues in relevant systems? | Anything related to their intestines and all the way to the | exit, wouldn't they lose a significant amount of their | ability to do their jobs properly? I am not saying they | should be able to start processing 5000kcal of carb heavy | food immediately in a single meal after the fasting stops | with no issues (as that 5000kcal meal can would give quite | a lot of healthy people who dont fast issues as well), but | would their intestines actually be able to function fine | again? I mean, for something even as banal as sphincter | muscles, I am simply lost. Is human body actually that | adaptable to handle it like a no big deal? | narrator wrote: | In long-term fast of more than a week there's the | possibility of refeeding syndrome. If the person fasting | hasn't kept up with their electrolytes, they can have | possibly fatal issues if they absolutely gorge themselves | when stopping the fast. When I end the fast, I am going | to proceed gently for the first couple of days before | resuming a normal diet even though I have used an | electrolyte formulation to keep my electrolyte levels at | an optimal level. | julianeon wrote: | You could always do the "lite" version like me. | | I eat one day and fast the next. I rode this very simple | procedure to melt away 40 lbs (was easy). I have been | doing this for about 3 months, lately my weights been | stable as I've skipped fast days. | | I also only eat for about one hour on days when I do eat; | normally it seems like the sugar rush becomes noticeable | at the one hour mark, so even if you eat for the whole | hour, that will pause you. | | My experience: | | 1st day of fasting is the hardest. But if you are fasting | every other day obviously you'll get used to it. | | You become aware that your imagination (imagining | savoring the food etc.) was a big part of your eating. | Knowing that it's easier to not eat. | | I don't know what it's like to skip food for multiple | days (well, more than 2), but for 48 hours between meals, | it's very doable, and stops feeling "heroic" (or needing | massive willpower) pretty quickly. It just feels like | your stomachs vacation day - which feels good. | obblekk wrote: | I didn't realize this until recently, but we don't actually know | every chemical compound that's in our blood. As in, I don't | believe there has been a study that takes 1 liter of blood and | just documents every chemical structure found (at any | concentration). | | Realizing that + learning about the seemingly vast gut microbiome | has definitely led me to feel more humbled about what we know and | can predict about human biology. | | I now think it's possible (but certainly not proven) that some | hard to anticipate cascade of compounds (produced by gut, or | foods, or environmental, or whatever) could be responsible for | significantly increasing subjective feelings of hunger across the | population at large, and this could lead to more calories being | eaten than needed. | | I'm actually optimistic that this has happened, because then | there might be an effective way to reverse the health problems we | see... much like removing leaded gasoline seems to have helped | reduce crime rates. | tamaharbor wrote: | Why is it scientists would have us believe that they know | everything definitively regarding covid, covid vaccines, | climate change, etc? | pc86 wrote: | Literally no scientist has ever said that they know | everything definitively about any topic, let alone those. | coding123 wrote: | But we ascribe policy as if they do know 100%. | Spivak wrote: | I think there's a difference between "we make and adjust | policy based on the strongest theory we have with an | extra dose of caution" and "we think science is | infallible." | pc86 wrote: | The fact that politicians are idiots, in addition to | surprising approximately zero people, shouldn't be used | to impugn science. | darkteflon wrote: | Mate, go over to the Atlantic (https://www.theatlantic.com) | and read through their coronavirus coverage starting all the | way back at the beginning of 2020. You have been sold a lie | in your little TikTok bubble. | adamrezich wrote: | there is this sort of modern attitude toward science that | tacitly assumes that we understand some sufficient majority of | the nature of reality, when in fact reality is apparently | infinitely fractal. | throwaway4aday wrote: | I think most of the gaps in our understanding of biology stem | from the scale at which we exist. Most biology takes place at | the cellular or even the molecular level, we only see the | very far removed macro-scale effects of a myriad of | intertwined processes. | mirceal wrote: | hah. not even close. we had moderate success in understanding | and modeling some phenomena, but in the grand scheme of | things we don't know much. which is both scary and great if | you have a curios mind | r3trohack3r wrote: | Have you come across the environmental theory of obesity? | | https://slimemoldtimemold.com/2021/11/23/a-chemical-hunger-p... | netizen-936824 wrote: | The complexity of life is nuts. Once you start learning about | how things work, you can see that we only know a tiny fraction | of what's going on | eastbound wrote: | Organic growth is like "Throw bits into the computer and see | whether they make NPM." | | ...And the complexity of an NPM project is nuts, actually. | zionic wrote: | I mean sure, I'd love a scalpel but right now we don't even | have a hammer. | | It would be fantastic to do something even as simple as shut | off the hunger signal for set intervals. | | Imagine if you literally couldn't feel hunger from say... | 10am to 6pm. There's all sorts of cool hacks we do to improve | humanity if we could get a grip on cravings. | mirceal wrote: | not only that, but our gut is literally the 2nd brain of our | bodies. Read somewhere that there are more than 200 million in | our gut. To put it in perspective, that's more neurons that all | the neurons in a dog's brain. | throwaway1777 wrote: | Highly doubt there is a silver bullet. There are likely a | myriad of reasons because diets and genetics are so diverse. | Sugar is the obvious villain though. | layer8 wrote: | > a study that takes 1 liter of blood and just documents every | chemical structure found (at any concentration) | | That's because we don't actually have the technology to do | that. You can test for specific compounds that you know how to | test for, and if their concentration is high enough. But | there's currently no way to e.g. go through a given sample | molecule by molecule. | DantesKite wrote: | Both these comments are a great way of putting it. I never | thought about this before. Very interesting. | daanlo wrote: | I thought you would be able to do this with a mass | spectrometer. Although you would probably need a lot of blood | :) | gxt wrote: | Exactly, IBM can make movies using individual atoms, surely | we aren't too far from being able to look at molecular | structures and deduce what compounds are in a sample of | blood. | heavyset_go wrote: | You'd typically need reference samples if you're trying to | get a typical lab to analyze compounds via mass | spectrometry, which would make identification of unknown | substances in blood hard for non-researchers. | montecarl wrote: | A mass spectrometer by itself, will tell you the mass to | charge ratio of ions in a sample. In most samples the | molecules themselves are not ions naturally and need to be | ionized. This can be done using a number of techniques, but | a common one is electron impact ionization, where electrons | are slammed into molecules causing them to fragment into | charged ions. This smashes the molecules up into small | charged chunks which can then be analyzed by the mass spec. | These mass spectra are good fingerprints for the original | molecule and can be mapped back to what molecule must have | been smashed to produced them. However, if you try to | analyze the mass spectrum of a mixture of molecules that | are similar you will not be able to deconvolute the result | into any unique answer, i.e. there will be many possible | mixtures of molecules that could have resulted in the mass | spectrum. | | This limitation of mass spectrometry can be overcome by | first separating out the mixture of molecules you want to | analyze into different fractions before they are ionized | and enter the mass spectrometer. One common way to do this | is to use a gas chromatography column. This works by first | heating the sample so that it turns into a gas, and then | passing it through a long column that is packed with a | material that will interact with the gas and slow some | molecules more than others. Often it is packed with silica. | In this way you get the technique called GC-MS (gas | chromatography/mass spectrometry). | | GC-MS is a fantastic technique for analyzing complex | mixtures but it will have its limits if there are too many | different types of molecules in the mixture. In blood there | will be tiny molecules like O2 and CO2 and giant macro- | molecules like DNA. There is no technique I know of that | can analyze such a wide range of molecular masses in one | go. Plus mass spectrometry doesn't directly give you the | structure just the masses of the fragments after you blow | up the molecules (or the total mass if a more gentle | ionization technique is used as is sometimes done for | macromolecules). | | I write all this just to explain how there aren't any | analytical instruments that you just inject a sample into | and out pops all the chemicals and their concentrations. | Blood is a amazing soup of different elements and molecules | and a full analysis requires a large number of steps and | different analytical techniques to get even close to fully | characterizing. | carlmr wrote: | Thank you, I've always wondered about these but was too | lazy to check. | Etheryte wrote: | What a gloriously through yet understandable explanation | of the problem and its context, thank you. | raylad wrote: | Mass spec (at least as of a few years ago) require | reference spectra to identify compounds. Without them, you | can guess at structure but it's not accurate. | RugnirViking wrote: | Something that's always confused me is how I get powerful | cravings for sugar, but am relatively untempted by salty foods or | carbohydrates, wheras my sister(very close in age to myself) | isn't tempted at all by sugar but is a sucker for salty foods. We | grew up in a presumably quite similar culinary environment. I've | often wondered If the differences can be explained by gut | bacteria. | | Also, surely the claim that this is the first study to show a | link between gut bacteria and food choice is wrong? I'm pretty | I've known about the link for years? | matthewdgreen wrote: | There's a ton of very new research on this. The big exciting | candidate right now is Akkermansia muciniphila, which seems to | emit a glucagon-like peptide that moderates appetite [1] (similar | to drugs like Wegovy, only maybe without the side effects.) The | western high-fat/carb diet also seems to cause Akkermansia | populations to drop precipitously, which may be either cause or a | separate side-effect of the obesity epidemic. | | Apparently supplementing Akkermansia in obese mice has extremely | beneficial effects on weight and all sorts of health measures. I | tried some from the only supplier in the US and (unfortunately) | noticed absolutely no difference, N=1. Still, I am eagerly | awaiting the day when someone conclusively nails the obesity | epidemic down to something as simple as gut dysbiosis. | | [1] https://www.nature.com/articles/s41564-021-00880-5 | alimov wrote: | Grain Brain is an interesting read that covers in a pop-sci way | some of the various research being done. | DoreenMichele wrote: | _Still, I am eagerly awaiting the day when someone conclusively | nails the obesity epidemic down to something as simple as gut | dysbiosis._ | | That's unlikely to happen. Nutritional content of produce has | gone down, people eat fewer home-cooked meals and we drive more | and walk less, among other things. So it's not likely to boil | down to "This one simple trick!" that can be solved with a | simple product one can buy for cheap. | matthewdgreen wrote: | If you look at the timing of the obesity epidemic you notice | that it has a very sharp "knee" in the US around the 1970s. | It does not coincide with the introduction of fast food or | the automobile or sedentary living, and contemporary people | exercise _more_ in many cases than they did in the 60s and | 70s, with vastly higher BMI as a result. The same pattern | occurs in other countries just at later times. And the effect | size is _huge_. Much larger than anything we can achieve with | diet and exercise (durably) or even the best weight loss | drugs. I don't know what's causing it, but "gosh people eat | poorly" doesn't seem like a good explanation. I thought this | was a good (amateur, but accessible) summary of some of the | stats: https://slimemoldtimemold.com/2021/07/07/a-chemical- | hunger-p... | DoreenMichele wrote: | _I don't know what's causing it, but "gosh people eat | poorly" doesn't seem like a good explanation._ | | I'm not sure what your point is because what I said boils | down to "There seem to be multiple factors, not any one | thing." | | I've lost multiple dress sizes by improving my health when | losing weight wasn't a goal at all. Among other things, | that experience informs my views and I don't really know | how to engage whatever point you are trying to make that | seems to not really engage with anything I actually said. | | But thank you for the link. It's got a take I hadn't | previously seen. | echelon wrote: | While I'm fairly convinced that a lot of dysfunction gets a | helping hand from microbiota imbalance, including such faraway | targets as pulmonary, cardiac, and even neurodegenerative | disorders [1], I think there's a simpler culprit: sugar. | Metabolism of simple sugars changes biochemical gears, and we | as a culture and society are heavy on its use. | | [1] https://news.ycombinator.com/item?id=29882347 | matthewdgreen wrote: | Sugar definitely seems bad, but doesn't explain why simple | fecal transplants are able to replicate many of the health | effects of a low-carb diet without the actual diet, at least | in some obese mice [1]. (PS I am definitely not an expert in | this area, just someone who is tired of eating low-carb to | maintain weight, and wondering why other people can just eat | normal food.) | | [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6199268/ | bbarnett wrote: | _The western high-fat /carb diet also seems to cause | Akkermansia populations to drop_ | | The West, typically, eats a tiny, tiny fraction of the fat it | used to. And also far less animal fat. | | Do you know what went in soups, stews? Bones, with fat, for | flavour, and energy, and nutrition. | | What were pies made of? Pies, made to allow older apples and | such, to be used past their best date? | | Loads of animal fat in the crust. | | And, especially in Canada, our pork is now leaner than beef was | 50 years ago! And our beef is silly lean. | | We eat far, far less fat than our ancestors, who would never | throw away such valuable, nutritious calories. | | If the simple metric is, why were we thin before, and | overweight now? And if the answer is "our diet changed", then | this logic means we should all be eating about 10x the calories | we currently do, in animal fat, and tapering off the rest. | | What if all those craving are just simply "the body needs more | nutritious fat". Just like our ancestors ate. | | What if we crave salty snacks, coated in vegetable oil (potato | chips), because our body desperately wants salty fat? | | Being overweight is far, far more unhealthy than eating more | animal fat daily. | | What if the cost of low fat diets, is an irresistable urge | which causes weight gain? | | If so, low fat diets are, therefore, very unhealthy... because | being overweight is far worse. | hombre_fatal wrote: | I'd focus on getting fruit, vegetables, legumes, fiber, and | everything that comes with it back into the western diet | before I'd look at animal fat as the silver bullet we're | missing. | | Too few animal products doesn't seem like the thing the SAD | is missing, either. | oblak wrote: | Indeed. All this talk about a proper diet without ever | mentioning anything but animal flesh and fat. | | Can't be the excess food intake. Like too much sweets and | meat. No. Fat people are not eating enough fat. It's so | simple. | wincy wrote: | I mean I lost 80 pounds literally eating cheap hot dogs | and kimchi for 6 months. It might be that simple. | ajsnigrutin wrote: | That's almost zero carbs (if we're talking about | "sausage" hodogs, and not "sausage-in-bread-bun" | hotdogs)... fat makes you feel full faster and longer, | and kimchi add vitamins and almost zero calories, so no | wonder you're losing weight :) | | Replace those with potato chips and chocolate, and you'll | be fat very soon :) | matthewdgreen wrote: | I think the upshot of much of this research is that sugar | and fat aren't directly the issue. That gut bacteria | actually have a much bigger impact on both energy | expenditure and appetite than we thought. Insofar as diet | has a major effect on obesity (in the epidemic sense | we're seeing in the US) it might be due to diet having a | harmful effect on gut bacteria. Or it might not. It's an | intriguing hypothesis, and it's disappointing to see it | devolving into an argument about "not eating too many | sweets." | nvusuvu wrote: | I eliminated food cravings in perhaps an unorthodox method. It | wasn't my intention, but I am better off for it I believe. I | started with a 72 hour fast (water only). After that, I had a | bite of a steamed carrot and the experience immediately after | tasting the carrot was the biggest natural high of my life. It | was like my brain dumped every pleasure producing chemical into | my bloodstream. I started to focus on healthy veggies and | fish/chicken with small servings of nuts and avocados. I lost 20 | pounds (so far) and don't craze processed sugars like I have in | the past. When you stop eating a lot of sugar, the gut biome | bacteria chlamydia starves I think, and you are much healthy for | it. | Tade0 wrote: | I had a similar experience when we introduced our child to | solids - we all ate the same meal so obviously added sugar and | salt were out of the question. | | Within two weeks I started experiencing flavours that I | previously had no idea were there - especially rice has a | different taste initially than after it's chewed. | | I used to eat those instant ramen noodles every other day. Now | I can't stand the salt content. | nvusuvu wrote: | I was telling people that the carrot tasted like candy to me | and they looked at me like I had lost my mind. | lostcolony wrote: | Dunno if you care or not since they're still not healthy | (just starch basically, but, instant ramen without the | 'flavor' packet has all sorts of great ways of preparing it. | Budget Bytes has some excellent suggestions - | https://www.budgetbytes.com/?s=ramen | QuercusMax wrote: | Starches like rice will taste different if you allow saliva | to work on them - your saliva contains enzymes which break | down starches into sugars. This is commonly demonstrated in | middle school science classes by having kids chew a saltine | cracker, and taste how it starts out bland and ends up | tasting sweet as you hold it in your mouth. | globular-toast wrote: | Actually _anjoying_ food is, somewhat paradoxically, a great | way to control weight. | | Watch fat people eat. It's like they are trying to maximise | calorie intake. Food is shovelled in. Bites are taken before | the previous one is even swallowed. They don't really enjoy the | taste of the food, they just want the feeling of hunger to go | away as quickly as possible. | | Watch how French people eat. It's not about survival, it's | about enjoyment. Each bite is savoured. Time is taken to | appreciate the food. It's one of the most important times of | the day. | | French people eat like they're making love. Fat people eat like | they're jacking off to porn to deal with the daily urges. | darkteflon wrote: | Needs citation. | heavyset_go wrote: | Eliminating sugars or salt will make you realize just how | overly sweet and salty most food that isn't prepared at home | is. | wincy wrote: | It's wild to me how heavy cream tastes sweet after you | acclimate to a low sugar diet. It has something like 1g of | sugar for every 12g of fat (if I remember from the label) | wincy wrote: | I think I did this too, but in reverse! Unfortunately I | couldn't get to the store fast enough after my 72 hour fast, | and my stomach hurt so bad that I ended up eating a Chalupa. | Then I gained 60 pounds. Oops. | standardUser wrote: | Similarly, I have found that every time I severely limit carbs | for a solid 3-4 days my appetite flatlines instead of rapidly | rising and falling throughout the day. And everything starts to | taste better. And I have way less gas. | colechristensen wrote: | > the gut biome bacteria chlamydia starves I think, and you are | much healthy for it. | | I believe you are thinking of candida which is a kind of yeast | which is fungi not bacteria. | vmception wrote: | fungi are smarter and more meticulous than bacteria, so I'm | willing to believe they could dictate our preferences | nvusuvu wrote: | Yes, you are right. candida. Thanks for the correction. | mark_l_watson wrote: | I think that you are correct. I have been on Dr. Fuhrman's | Eat to Live diet a few times: start by eating no processed | food and drastically reduce sugar intake unless it is berries | or a little fruit. After about a week, the level of candida | in your system is reduced to levels closer to what humans had | > 50 years ago. At this point, all sorts of food cravings | (especially deserts) go away, and homemade meals from natural | ingredients taste very good. The first time I went on this | diet, I felt 10 or 15 years younger with lots of energy. | nvusuvu wrote: | This has been my experience. I have lots more energy and | zero cravings and hungry pains are truly a thing of the | past. | The_rationalist wrote: | armchairhacker wrote: | This 100% lines up with my experience, every time I've changed my | diet I started to prefer the foods I was eating. Instead of | palate fatigue, eating something a lot causes me to crave it | more. | | I used to eat a diet of mostly frozen foods. Then I made an | effort to eat more vegetables and suddenly started craving | vegetables. I use to prefer high-carb low-fat, then I started | eating more meat and gradually shifted to preferring low-carb | high-fat, except when I took a break and alternated between the | two. | codyb wrote: | I've been getting some bad acid reflux lately leading to gnawing | in my stomach due to a lifestyle with lots of going out recently | as the weather gets better and more events start happening and | everyone comes out from covid and the winter. Looking forward to | a hopefully relaxing May to take it easy for a bit! | | It's amazing how much yogurt helps though. It's very noticeable, | and very quick. | nwe wrote: | In case anyone get the idea from reading the article that | tryptophan and serotonin are good for you, check out Ray Peat and | he has extensive writings on them. | rednerrus wrote: | My observation is that there are two type of brains when it | comes to processing serotonin. One type processes it quickly | and increased serotonin increases good feelings. The other type | processes it very slowly and increased serotonin creates all | kinds of problems for this type. This type also tends to | struggle with slow processing of catecholamines. ___________________________________________________________________ (page generated 2022-04-22 23:00 UTC)