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Fasting Affects the Brain
- g-clef 8y ago...in mice.
- pazimzadeh 8y agoWith a human study underway.
- mrspeaker 8y agoSeems like the link is dead. Anyone have a summary (or cache)? I've been thinking of fasting, just to test it out - but it's hard to research as a topic because there is so much pseudo science and so many "miracle diet" blogs out there.
- neves 8y agoCached text version: http://webcache.googleusercontent.com/search?q=cache:YXae0gVGTJoJ:www.brainfacts.org/thinking-sensing-and-behaving/diet-and-lifestyle/2018/how-does-fasting-affect-the-brain-071318&client=firefox-b-d&hl=en&gl=br&strip=1&vwsrc=0 http://webcache.googleusercontent.com/search?q=cache:YXae0gV...
- partiallypro 8y agoHug of death, I believe. I've been fasting this year and it has worked in terms of weight loss, down nearly 20lbs since December. As far as brain effects...I'm not sure if it's related to the diet or just because it's summer and I'd rather be outside, but I've become somewhat apathetic to work.
- hashberry 8y ago> And that’s what we’re finding in lab animals — the brain and body actually perform better during fasting. In the case of the brain, cognitive function, learning, memory, and alertness are all increased by fasting. I find this to be true whenever I fast for 12+ hours. It feels like I'm on a drug. It's strange to realize how not eating can be good for you. Fun trivia: the longest a human went without food is 382 days. [0] [0] https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast
- everdev 8y agoYeah, it feels like getting a "second wind" when exercising. Getting there can be brutal though as my mind and body feel weak and it's hard for me to do any highly cognitive tasks. But after my body accepts it I feel "in the zone" and I don't want to eat and disrupt the feeling. I've never gone longer than 18hrs though.
- shanehoban 8y agoI'm not a doctor or anything but my own interpretation of this affect is that you are depleting your glucose stores, and when you reach ketosis, you once again have energy to burn. https://en.wikipedia.org/wiki/Ketosis https://en.wikipedia.org/wiki/Ketosis
- magnamerc 8y agoI've done 7 day water fasts (I try to do them quarterly, or bi-annually) and I find by day three I'm full of energy to the point where I have a hard time sleeping. I'm also way more productive during those 7 days. The only thing that tends to suffer is my weight lifting. I drop in strength a tiny bit, but not nearly as much as you'd expect. I also drop about 5-10 lbs in mass, with about half of that coming from water. Almost no lean muscle loss as far as I can tell. In fact, I always look shredded after the fast. I just ease back in with keto for a week or two, then back to low carb diet.
- ohaideredevs 8y agoBeing hungry increases alertness. This is discussed in "The Willpower Instinct", in the context of keeping you from sleeping well. It's natural - the body knows it needs to find food, so it makes you hyper until you do, negatively affecting the ability to get essential sleep. So, there is nothing weird about what you are experiencing - it's like wanting to get air when you are under water. Doesn't make it a good way to do things. It's amazing how much of a trend fasting is lately.
- magnamerc 8y ago
- tmysl 8y agohttp://webcache.googleusercontent.com/search?q=cache:YXae0gVGTJoJ:www.brainfacts.org/thinking-sensing-and-behaving/diet-and-lifestyle/2018/how-does-fasting-affect-the-brain-071318+&cd=1&hl=en&ct=clnk&gl=us http://webcache.googleusercontent.com/search?q=cache:YXae0gV...
- RenRav 8y agoThanks, I was having trouble on my phone accessing the site.
- mcfunk 8y agoInteresting that this is "news" when the medical understanding of fasting and ketosis is pretty far along. Highly recommend the book "The Complete Guide to Fasting" by Dr. Jason Fung. When you think about it, while the "naturalness" argument is always suspect, it's very odd that humans eat as often as we do in the US, and unsurprising that negative health consequences follow (and positive health consequences follow fasting).
- coldtea 8y ago>Highly recommend the book "The Complete Guide to Fasting" by Dr. Jason Fung. Such books and doctors, promoting this or that diet, heavily cherry-pick from research papers, they don't reflect the scientific consensus on the matter.
- mcfunk 8y agoI'll be interested to see where the scientific consensus is in 10 years. I think the evidence is very much on the side of the hormonal theory of obesity and fasting, especially given the monumental failure of the "calories in calories out" model.
- wyldfire 8y ago> especially given the monumental failure of the "calories in calories out" model. Can you explain this in more detail? CICO seems like it might oversimplify things but it always seemed like a really sane basis for helping shape your diet. If you need to lose weight, you should plan meals to create a calorie deficit. But yes, I would not be surprised to learn that fasting on day X and consuming double your normal calories on day X+1 are not equivalent. The description of CICO as a "monumental failure" sounds like there's substantial evidence to the contrary -- can you share more info?
- qntty 8y agoThis article makes a case against a calorie-centric approach to dieting. It boils down to something like Michael Pollan's "Eat food, not too much, mostly plants." A guy (who has since become an expert in public health) wasn't able to control his weight using standard calorie-counting techniques and had a lot of success changing his diet to "high quality" (as opposed to "highly processed") food. The article isn't super clear on specifics of what that means but it sounds like there might be something to it. Also worth noting that he began exercising in between this switch. https://www.1843magazine.com/features/death-of-the-calorie https://www.1843magazine.com/features/death-of-the-calorie
- istjohn 8y agoI wonder how these findings can be reconciled with the research on the importance of breakfast for school children. There are obvious differences between the two issues, but nevertheless when I think about how to apply these insights, they seem to conflict, and I'm not sure how to resolve those conflicts. Edit: The biggest difference is age, but conventional wisdom says adults, too, should eat a good breakfast before an important exam. Should you skip breakfast before your LSAT?
- mcfunk 8y agoThe simple answer is that children's physical and hormonal makeup is different to that of adults. I've always seen it recommended that children should not fast.
- coldtea 8y ago>I wonder how these findings can be reconciled with the research on the importance of breakfast for school children. A lot of that research is bogus anyway. https://www.theguardian.com/lifeandstyle/2016/nov/28/breakfast-health-america-kellog-food-lifestyle https://www.theguardian.com/lifeandstyle/2016/nov/28/breakfa... https://priceonomics.com/how-breakfast-became-a-thing/ https://priceonomics.com/how-breakfast-became-a-thing/
- Zaak 8y agoIf I had a big test coming up, I wouldn't experiment with fasting on the day. However, if you've been fasting while studying and you find it to be a help, then fasting the day of the test is probably a good idea.
- faissaloo 8y agoI know it's anecdotal but I've only managed a few points increase by fasting.
- arkitaip 8y agoI'm not sure this research applies to kids. Also, you can totally have breakfast and still be fasting, i.e. by following a 16:8 diet (fasting during 16 hours, eating during a 8 hour window).
- Zaak 8y agoFasting is a periodic religious observance for me. The main effect I have noticed is increased irritability, but then I've never done cognitive tests while fasting.
- throwaway123x2 8y agoThat might be from the caffeine withdrawals. I'm trying it wihtout caffeine at all this year, and it's been great.
- brink 8y agoEspresso has no calories
- Tharkun 8y agoGrandparent is talking about religious fasting, not a diet. It's likely not about calories.
- Zaak 8y agoIndeed. It's abstaining from all food and drink for a goal of 24 hours. I generally manage about 12, but it's something I'm working on improving.
- beagle3 8y agoDo note that almost everyone else only abstains from food, but does drink a lot of water (often with electrolytes). It makes a huge difference, irritability and otherwise.
- Zaak 8y agoThat's good to know. Fasting for me is partly an exercise in choosing to do something that's uncomfortable for my body to achieve a higher purpose. It is explicitly not supposed to be damaging or unhealthy in any way (people who are sick etc are discouraged from fasting). I will look into staying hydrated while abstaining from food.
- sepisoad 8y agoyes fasting can have benefits, but the way most Muslims do it (in summer specifically) actually hurts. your body needs a minimum amount of water and salt to work properly throughout the day.
- x1ph0z 8y agoWouldn't that be mitigated by having enough water before he fast begins? I usually gorge water before and after my fasting for the day.
- neuralzen 8y agoI would think that depends. In Indonesia a lot of people do just that and seem ok (though lots of hacking and coughing), and in Jordan I saw construction workers toiling in the sun all day who wouldn't drink water while fasting, which seemed dangerous to me. The Bedouins I met in Wadi Rum were more lax, saying while traveling or working, they are allowed to eat and drink even during Ramadan, as a matter of a practicality...being in the desert and all.
- dorfsmay 8y agoCommon! We're talking about what? 12 or 15 hours? The body is a lot more resilient than we give it credit for. Think about it, you don't drink while sleeping, so that's 7 or 8 hours right there. If you ever been not drinking for 2 or 3 hours before going to bed, than you're close to 12 hours. In fact, google "dry fasting", lots of people are experimenting with it. "dry fasting" for 24 hours feels very different than "water fasting" for the same amount of time. There is no published scientific studies about it, I suspect because of liabilities fear when people go to extremes, but I am convinced that short term (~ 24 hours) it is different and beneficial. Every theory you will find online is bro science, but, you can't dismiss hundreds (thousands) of people experimenting and and reporting positive results.
- zwaps 8y agoAs someone who does Ramadan right now, I partly disagree. You are right that not drinking has adverse effects on cognitive performance, at least in the initial days. But remember that this fast is done for mental reasons, and not physique. Even though it can be difficult, I really look forward to it throughout the year. It does bring euphoria and increased focus and other positive "mental" effects. To say it has no benefits is obviously wrong. It can be a great experience!
- rossenberg79 8y agoI stopped doing fasts because even though I did notice a boost to my productivity, most of it was due to not having to stop in the middle of the day to eat or waste time thinking about eating. In terms of cognitive benefits, going for a run for 30 minutes in the morning still seemed far superior.
- bluedino 8y ago>> going for a run for 30 minutes in the morning still seemed far superior Why not both?
- Goronmon 8y agoFasting combined with exercise sounds like a recipe for overeating after the fact.
- mcfunk 8y agoOnce the body gets habituated to using fat stores for energy rather than glucose or glycogen, there's no particular need or urge to eat after exercise.
- rossenberg79 8y agoWhat if you are low on fat stores?
- phonypc 8y agoDefine low. Unless you're a competitive body builder on show day, you've probably got enough fat to cover a few weeks worth of energy needs.
- rossenberg79 8y ago12% is not that low, but hardly weeks worth of energy needs.
- ravenstine 8y agoI sometimes intermittently fast for 24 hour periods, but recently I've switched to skipping breakfast, which effectively works out to be a 17 hour fast for me if I eat dinner at 6pm and have lunch at 12pm. Everyone says it's the most important meal of the day, but I haven't found convincing evidence of this(especially that which isn't sponsored by grain and sugar producers), and not having a huge insulin spike at the beginning of the day seems beneficial. The results are profound. I'm a lot more focused and emotionally stable. The only distraction is the frequent "gotta find food" feeling, but that usually subsides within minutes. It's usually not even true hunger, but an impulse instilled in me by a culture focused on eating and "never starving". Pro-breakfast proponents say that eating breakfast results in eating less throughout the day, but I can't say this has been true at all for myself. When I ate breakfast, I also would snack more throughout the day. Without breakfast, I look forward to meals more and those two meals, which are almost always ketogenic, are more satisfying. The only negative effect I'm having is that my sex drive has plummeted to near-zero. I suppose that's a good thing for focusing on work, but I wouldn't want to keep that up forever.
- UpperBodyEimi 8y ago“Breakfast is the most important meal of the day" was an advertising slogan for Kellogg's.
- daenz 8y agoI'm in awe at how well that advertising slogan permeated culture as pseudoscience. I hope someone at Kellogg's got a nice bonus for that.
- tw1010 8y agoThat sounds plausible (and interesting) but do you have a source for it?
- pilsetnieks 8y agoNo, that's false. It was actually General Foods for Grape Nuts: https://priceonomics.com/how-breakfast-became-a-thing/ https://priceonomics.com/how-breakfast-became-a-thing/
- tw1010 8y agoWhat doesn't affect the brain?
- virtuexru 8y agoIntermittent fasting changed my life. I've quit coffee, eat way healthier and generally feel better & have a uplifted outlook on life. I'd definitely recommend the Zero app. I do the 13 hour fast but sometimes will go up to 15-16-17 hours whenever possible. Also don't forget to take a cheat day every now and then!
- agumonkey 8y agoI found that skipping hunger (not real nutritional needs, the need to satisfy a moment through eating) made me a little hyperactive and in a way if I divert this slightly manic like rush, I can do things in deep, not in flow but almost.
- eden_hazard 8y agoAnecdotal evidence but this is my third day of fasting and my productivity is significantly higher. Oddly enough, the hunger I feel is similar to what I'd feel if I skipped breakfast going into lunch.