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Self-Control Relies on Glucose as a Limited Energy Source (2007)
- mrfusion 9y agoWouldn’t this mean dieting would be impossible?
- datawarrior 9y agoNo but it would explain why so many have difficulty. This isn't all that interesting to be honest. We've known for a long time that energy levels have a direct effect on brain function. That self control is a "function of the brain" is obvious and subject to the same principals. Garbage in, garbage out as the saying goes. Proper diet will improve brain function and "self control". From the paper: "Resisting the temptation to eat the cookies presum- ably depleted an energy resource that could otherwise have been used to persist on the subsequent task" To your point, the best way to diet then would be to avoid the temptation which would mean less use of glucose in the resisting of it.
- pwinnski 9y agoNot impossible, but difficult. And more difficult for some than others depending on initial glucose level.
- otakucode 9y agoDieting is possible... but you should expect to have significantly decreased self control in all other areas of life at least for as long as active self control is necessary to refrain from eating poorly.
- vixen99 9y agoIs this an attested phenomenon? How does it work?
- otakucode 9y agoI was just reasoning from the studies that exerting self control depletes your ability to exert more self control. In the study most often cited there is actually an interesting link to this exact phenomenon, though. The participants were asked to refrain from eating chocolate (although there is no indication that these people were trying to diet for any reason). Afterward they were tested on standard decision-making tasks, at which those who had to resist eating chocolate performed significantly worse than those who didn't. Then, they were given a glucose drink and their performance returned to normal. A person dieting would be both exerting self control to resist eating things and also resisting things that would provide more glucose for the brain to be using. However, I seriously doubt this is specific to self control. I would imagine performing any action that depletes glucose in the brain would have the same effects. Prioritizing tasks and deciding tasks to delegate are a couple I've read which are supposed to be very energy-hungry (I've been reading 'Your Brain At Work' recently and its mentioned in there).
- MattRix 9y agoThis would explain why the ketogenic diet is so effective, beucase your brain starts using ketones instead of glucose for energy. I know for me, as a person with ADHD, I have MUCH better self control when I'm on keto then when I'm not. It's the main reason I stick to the diet.
- pizza 9y agoDieting that resulted in exorbitant glucose variability, perhaps, yeah. But there are a lot of other factors at play than just glucose/insulin - tiny example eg. leptin ~> activation of anorexigenic POMC neurons ~ melanocortin ~ glucocorticoids/appetite/obesity/sexual behavior/sleep + higher fasting insulin levels
- wastra 9y agoThis is an interesting point. As others addressed the main issues, I would just add that dieting does not need to be continuous exercise of will power. It may just take will power in establishing an environment not surrounded by unhealthy food, e.g. when shopping. I would not relate this point to serum glucose in any way, however.
- hyperpape 9y agoImportant to note that there's a lot of literature surrounding ego depletion, but it's been called into question for whether it can be replicated: http://www.slate.com/articles/health_and_science/cover_story/2016/03/ego_depletion_an_influential_theory_in_psychology_may_have_just_been_debunked.html http://www.slate.com/articles/health_and_science/cover_story... https://en.wikipedia.org/wiki/Ego_depletion#Reproducibility_controversy_and_conflicting_meta_analyses https://en.wikipedia.org/wiki/Ego_depletion#Reproducibility_...
- lkesteloot 9y agoRight. Also more notes and links here: http://slatestarcodex.com/2015/03/12/book-review-willpower/ http://slatestarcodex.com/2015/03/12/book-review-willpower/
- lotyrin 9y agoGlucose depending on performance of a task seems pretty obvious as does performance of a task being dependent on glucose levels; is there any reason to believe that the tasks being rooted in self-control has any bearing on the results here? I would expect to see similar results with any mental tasks, and these self-control related tasks are seemingly chosen only to make for an attractive headline (taking advantage of controversy around ego depletion and the layperson's interest in matters of ego in general).
- kazinator 9y agoCan someone point out where in the paper they address the objection that a declining level of glucose doesn't necessarily indicate glucose was "used up"? Maybe some endocrinological mechanism (like insulin) simply triggered the uptake of glucose into various cells somewhere in the body. People cannot be in an excited state, like suppressed arousal of various kinds, without the body being involved.
- wastra 9y agoThis and many other points are left unaddressed by the authors. They fall at the first hurdle, so I hope this discussion can move on to some of the other interesting things people have mentioned.
- munificent 9y agoHave there been follow-up studies on this? An interesting experiment to conduct would be to give participants a shot of either glucose or saline and then test their self-control to see if increasing blood glucose increases performance.
- maneesh 9y agoSure, some studies have been run, though as an earlier commenter noted, replicability has been called into question. http://www.indiana.edu/~abcwest/pmwiki/CAFE/Wang%20-%20Sweet%20future.pdf http://www.indiana.edu/~abcwest/pmwiki/CAFE/Wang%20-%20Sweet... (summary here: https://books.google.com/books?id=evc6jaibNd8C&pg=PT52&lpg=PT52&dq=soda+willpower&source=bl&ots=a8p0KdAysE&sig=WumdW5Zai-ttcnwxDw37TzcpgHM&hl=en&sa=X&ved=0ahUKEwiR3cSd_onXAhVE04MKHdOHBu0Q6AEIRzAJ#v=onepage&q=soda%20willpower&f=false https://books.google.com/books?id=evc6jaibNd8C&pg=PT52&lpg=P...)
- Goosee 9y agoOne of the reasons I posted this is because I wanted more discussion on the topic of this paper. On the website, I didn't see much of a discussion happening. As in the comments here, it seems that the term coined for this is "ego depletion". Recently I've noticed many articles on HN how sugar, carbohydrates, dieting, etc. affects the brain, gut, and overall human body. Ego depletion is now on my list of topics to research further because I want to know more about the human body. I always thought of my Kinesiology class in university to be important because it taught about the relationship between the health of the human body and its environment. I hope there will be more findings in the future so we can, in a sense, optimize ourselves. For example, based on this paper it seems that eating a snack when studying can lead to better processing information and staying focused.
- deleted 9y ago[deleted]
- chiefalchemist 9y agoPer your last sentence, it might not be to the level of detail you're looking for but I really enjoyed "Your Brain at Work" by David Rock. I had more than a couple "ah, that makes sense" moments. That aside, the gut (bacteria) / brain connection gets more and more fascinating. There's so much about our personal inner space that we have yet to understand. Amazing.
- JumpCrisscross 9y agoThe title threw a flag in my mind because ego depletion is a recently-debunked hypothesis [1]. [1] http://www.slate.com/articles/health_and_science/cover_story/2016/03/ego_depletion_an_influential_theory_in_psychology_may_have_just_been_debunked.html http://www.slate.com/articles/health_and_science/cover_story...
- lhuser123 9y agoMaybe a little off topic, but you could consider also how different are those effects on different kind of people. I find lots of info for the question of what to eat, but not so much to the question of who eats it. Does this food will have the same effects on a young person vs an older one? What about people with a slow metabolism?
- capisce 9y agoHow does this interact with intermittent fasting or low-carb diets?
- zinssmeister 9y agoI do both of these things and especially when I am on a low-carb diet I have a very short fuse. Politeness goes out the window and compromising as well.
- MattRix 9y agoHow low do you mean when you say low carb? And for how long? Whenever I first start doing keto I can be irritable, but after getting into ketosis I have much more self control (way more than when not dieting at all)
- zinssmeister 9y agoI do it a month at a time and yeah I eventually get over it but never fully into the same calm state as with carbs
- freeflight 9y agoI remember seeing a paper about relationships between genetic addictive disorders, impulse control, and carbohydrate intake. Tried before finding it, but just can't remember the right terminology. As somebody with a family history of addiction, I can confirm that I get all kinds of cranky without my carbs. Imho some brains just crave those constant dopamine kicks, losing all impulse control in the process, carb intake seems to play a role in that whole dynamic [0][1]. A couple of years ago I did some "metabolic balance" diet which was very low carb for a couple of months, mostly to treat my migraines. After initial irritation, I felt really good physically but I had a constant craving for all the tasty carb stuff, like white bread/noodles, wearing me down mentally. I don't think I could live like that for years. [0] https://www.ncbi.nlm.nih.gov/pubmed/1349715 https://www.ncbi.nlm.nih.gov/pubmed/1349715 [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131727/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131727/
- 9y ago
- pishpash 9y agoThis is some joke paper right? Look at Figure 1.
- asynchronous13 9y agoWhat do you consider a joke about figure 1? The methodology and results are described in the text on the same page. How could it be improved?
- MattRix 9y agoDid you bother to actually read the paper?
- digitalmaster 9y agoI kinda wish that there was a simple way to quickly see if a paper has been peer reviewed. Findings like these are interesting observations at best until they've been replicated and controlled by independent parties... Still an interesting study. :)
- ASpring 9y agoI think you're just talking about replication. Peer review is the process where authors submit a manuscript and receive feedback from reviewers about the merits of their paper and how to strengthen it. This was published in the Journal of Personality and Social Psychology, an APA Journal. You can find their peer review process here (under "The Peer Review Process"): http://www.apa.org/pubs/authors/new-author-guide.aspx http://www.apa.org/pubs/authors/new-author-guide.aspx
- skybrian 9y agoThat would be nice, but it's my understanding that to really know what's going on in a scientific field, you need to read a bunch of papers in the field, not just one paper. It would be great to see more summaries of papers from trustworthy sources. For computer science there is The Morning Paper [1] but I don't know what there is for other fields. [1] https://blog.acolyer.org/ https://blog.acolyer.org/
- wastra 9y agoA lot of peer reviewed literature is also junk, and occasionally non-peer-reviewed papers are breathtaking. One of my favourite (peer reviewed) articles ever is: http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0020124 http://journals.plos.org/plosmedicine/article?id=10.1371/jou...
- mtw 9y agoThis is simplistic. When I am on a low carb diet but for whatever reason decide to eat a doughnut or anything loaded with simple sugars, then I begin to be irritable, have cravings and generally less focused on work. The findings applies only for people who are stuck on high-carb diet
- zzalpha 9y agoYour reading is simplistic. This is talking about blood glucose levels, which is influenced by many factors, including glucose production in the liver.
- nazgul17 9y agoAlso, if your glucose level increases too much, your body deals with it by taking it all away, being you into a sugar low. Afair ;)
- leovonl 9y agoHis reading is simplistic, but so is the article: there is no mention about different metabolic states, for instance. The brain depends on a very small quantity of glucose to function - it arguably is more efficient with ketone bodies, for instance [1] - so covering not only glycolysis seems like an incomplete research. [1] https://blogs.scientificamerican.com/mind-guest-blog/the-fat-fueled-brain-unnatural-or-advantageous/ https://blogs.scientificamerican.com/mind-guest-blog/the-fat...
- wastra 9y agoYes, this is another flaw, but there are much bigger flaws in their work! Also, they only fasted people for 3h. I've sucked a lot of junk out of peoples' stomachs who have had longer fasts, so this is not even a glycogenolisis phase: they could easily have been digesting food still. The participants were students, so maybe some had drunk alcohol, which, like a ketone is a two-carbon molecule...
- darpa_escapee 9y agoA spike in blood sugar is not the same as not having depleted your normal blood sugar concentration.
- purplezooey 9y agoI wish some people at my workplace would get a healthy dose of ego depletion. ;)
- jonnycomputer 9y agoI'm pretty skeptical of the ego-depletion model; it doesn't seem to explain anything that a "self-control is aversive" model wouldn't.
- bonniemuffin 9y agoI think I'm on board with your "self-control is aversive" model. Practicing self control just, well, sucks, and makes me not want to do it anymore!
- jonnycomputer 9y agothough why self-control might be aversive poses something of an evolutionary conundrum.
- throwawaylalala 9y agoWhat if you are in nutritional ketosis?
- zzalpha 9y agoI don't understand the question. It's not like a ketogenic diet results in a lack of blood glucose... which is good, because if it did, it would kill you. https://en.wikipedia.org/wiki/Gluconeogenesis https://en.wikipedia.org/wiki/Gluconeogenesis
- ghostbrainalpha 9y agoAs you are getting INTO ketosis you will have a window with lower glucose in your blood, and according to this less self control. As your body begins to burn fat to create its own glucose, your self control should be very constant, never dipping to low from lack of glucose. You don't get super-self control from a sugar high, so there is no benefit to high levels of glucose in the blood. Its just good to avoid the extremely low dips which someone in ketosis will never have.
- surfmike 9y ago“initial acts of self-control impaired performance on subsequent self-control tasks, butconsuming a glucose drink eliminated these impairments.” So, having a soda will replenish your ability for self control?
- wastra 9y agoI'm a physician. There are a lot of problems with the original article. The body is excellent at maintaining glucose concentration in the blood with food or with days of fasting. Glucose is the primary short-term energy source for most cells. The brain's energy requirements vary very little with "thinking" despite the assertions to the contrary in the introduction of this article. PET works by noting the slight transient increases in some brain regions with active thought, but moments later (as that 20% of blood flow goes swishing through the brain) more glucose is available. Meanwhile you are digesting sugars and carbohydrates, and your liver is supplying most of your fresh glucose if you are a fasting adult. Already, before reading the article, I have a low pre-test probability of their hypothesis being true, so they need extraordinarily strong evidence to make their point. Instead, there is a very weak chain of experiments, poorly reported, with borderline statistical significance. Poor charts, no tabulated results, just terrible. The primary problem is that they assert that glucose fluctuations occur due to the exercise of willpower. They try and fail to show this with their first experiment. However, their "results and discussion" combined section shows that their control group before and after glucose were very close to their post-intervention group glucose. p327 para 1. This shows how weak their statistics and data are, and from this point, you can throw the whole study in the trash.
- grzm 9y agoWould you care to show your work? I'm sure there are many here that would be interested, not only in your results, but how you arrived at them, particularly if they're presented in a way that would allow others to apply them to other papers they come across.
- robotresearcher 9y agoUser Wastra didn't claim to have done any work beyond reading the paper critically, or have any results. He/she gave a concise review of the paper: that's the output of the reading. What are you asking for?
- grzm 9y agoYou're right with respect to reading the paper critically. What I'm looking for in particular is how 'wastra arrived at "there is a very weak chain of experiments, poorly reported, with borderline statistical significance. Poor charts, no tabulated results, just terrible."
- efitz 9y agoThe article should have been titled “low blood sugar puts one in a bad mood”.
- wastra 9y agoThey could have gone with: "Sloppy scientists delude themselves about unlikely hypothesis" People repeating the fiction that "low blood sugar puts one in a bad mood" puts people in a bad mood when they haven't had sugar in the last twenty minutes. We evolved in a low sugar world and did just fine: or was everyone moody from 200,000 years ago until about a century or two ago?
- leovonl 9y agoThe study doesn't mention this anywhere, but one can assume it considers only a state of glycolysis. This makes the the title/conclusion a bit misleading. In case of ketosis [1], the brain mainly relies on ketone bodies for fuel.. I'm curious about how one's brain would perform in such state - judging by personal experience, the results would be very different. [1] https://en.wikipedia.org/wiki/Ketosis https://en.wikipedia.org/wiki/Ketosis
- opportune 9y agoWhat differences in your thinking did you personally notice while in ketosis?
- bonniemuffin 9y agoFor me, my mental energy and alertness levels are more stable, because I'm avoiding the blood sugar roller coaster that I get from eating sugar/carbs. When I eat carbs, most of my day is either "I'm so hungry I can't think", or "I just ate, food coma", and I'm only alert and maximally productive for the brief time after the food coma wears off and before I get hungry again. With keto, hunger and fullness are less distracting feelings that don't impact my attention as much.
- lhuser123 9y agoWhere can I read more about that type of diet ?
- jinglebells 9y agoDunno if it helps, there's a lot of discussion over at https://www.reddit.com/r/keto/ https://www.reddit.com/r/keto/
- wastra 9y agoPeople often say this, but I'm not yet convinced it has a fully or even partially physiologic basis. One way to do an experiment would be to fast someone for 48h (about when you completely run out of glycogen, and ketones start to ramp up from fat catabolism), and while fasting, infuse glucose, blinded, into them. I wonder whether people could tell whether they are getting IV glucose or IV saline, just by how they feel. Maybe someone already did this experiment.
- goodroot 9y agoAn HN recommended book The Ancient Art of Stoic Joy by William B. Irvine comes to mind when reading this. Here's a neat quote: We should use our reasoning ability to overcome negative emotions. We should also use our reasoning ability to master our desires, to the extent that it is possible to do so. In particular, we should use reason to convince ourselves that things such as fame and fortune aren’t worth having—not, at any rate, if what we seek is tranquility—and therefore aren’t worth pursuing. Likewise, we should use our reasoning ability to convince ourselves that even though certain activities are pleasurable, engaging in those activities will disrupt our tranquility, and the tranquility lost will outweigh the pleasure gained. The idea of practicing will-power, learning to decline known-pleasurable outcomes as a form of practice, is a well tested idea in stoic philosophy. The practice seems to suggest that there is an energetic ebb and flow of indulgence that can be countered by refining one's ability to reason.
- bayesian_horse 9y agoThis would mean meditation should lower glucose levels, which it doesn't. Meditation (or other self-control disciplines) doesn't help with hyperglycemia in diabetes, either. It would also mean that during a week-long fast self control should be almost impossible. Which it isn't, or it wouldn't last for a week or two. I'm sceptical.
- gcoda 9y agoLiver can manufacture glucose to negate some of points you make. But i am skeptical too, this might be withdrawal symptoms. Since i started no sugar, no carbs diet my self control improved a lot, but that maybe self-deception
- bayesian_horse 9y agoIt may be practice.
- numismatex 9y agoI'm not so skeptical about the macro as I am the micro. Think of it this way -- sugary drinks are motivational / energetic -- look at what happens when someone imbibes a sugary soft drink. Next, consider that it may be that hyperglycemia is noted as leading toward a positive patience level where without it, hypoglycemia sets in as a negative patience level. Lastly, consider that this may just be observed positive reinforcement, and without it, the actions aren't taken as easily. I believe the science of the paper is bullshit, the theory, but the experimental results they used to derive the theory, not at all.
- kbutler 9y agoThis is why, when I eat a piece of chocolate, I then have so much more willpower to avoid eating the next piece of chocolate. Oh, wait. That isn't how it works at all...
- titzer 9y agoI don't care what your p values are; put some error bars on your graphs. I wanna see the distribution.
- analogmind 9y ago"Moreover, despite our manipulations, we do not intend to advocate consuming large quantities of sugar as an ideal strategy for improving self-control"