6 ms·

Just gonna put this out there that this is dangerous, faddy advice. Fasting is a road to eating disorders and is much harder on your organs than eating nutritio

Just gonna put this out there that this is dangerous, faddy advice. Fasting is a road to eating disorders and is much harder on your organs than eating nutritious food. If it "works for you" thats fine but I hope someone will always put it out there that fasting is dangerous, unsupported by evidence and more dangerous than you can know. Fasting gives you a dopamine dump to give you the energy to find food. Not because it is in anyway good for you. Fasting makes people feel good after ending the fast because your body is relieved to no longer be starving. These dynamics are well understood in the context of eating disorders where "health fasting" is a well known symptom and excuse. It's crucial to note that most studies on intermittent fasting have been short-term and conducted on animals, focusing on immediate changes like glucose levels rather than long-term health outcomes. This lack of extensive scientific data calls for caution in adopting intermittent fasting, especially for individuals with specific health conditions or vulnerabilities.

nerdponx 3y ago
2-5 day fasting seems extreme. I think most intermittent fasting recommendations are more like "skip lunch 3 days a week".
- xboxnolifes 3y ago
  Usually it's more like skipping breakfast and not snacking after dinner. Skipping lunch isn't much of a fast if you're eating breakfast at at 7am and dinner at 7pm. But eating dinner at ~7pm and having your next meal be lunch is ~16 hours without eating.
giraffe_lady 3y ago
I don't encourage people to fast but it's also not true that it's unsupported by evidence. It's an ancient and widespread practice in nearly all of the major world belief systems. Billions of people fast, and there is a massive cross-cultural body of writings about the effects of it. Which is not the same as modern peer-reviewed medical study, no. But it's not "no evidence" either.
- MeImCounting 3y ago
  https://clindiabetesendo.biomedcentral.com/articles/10.1186/s40842-023-00152-7 https://clindiabetesendo.biomedcentral.com/articles/10.1186/... https://centerfordiscovery.com/blog/the-dangers-of-intermittent-fasting/ https://centerfordiscovery.com/blog/the-dangers-of-intermitt... I take the stance that health fasting is vastly different in effects from fasting as a religious observance. For instance the frequency and duration of so called "Health fasting" among other factors including the fact that "health fasting" seems to self select for people already at risk of disordered eating.
  - giraffe_lady 3y ago
    Yeah I think I agree with that. I'm skeptical of fasting outside of a specific tradition and guidance. But don't like to see the value of those traditions dismissed either.
xk_id 3y ago
> Fasting gives you a dopamine dump to give you the energy to find food. The hunger-hormone ghrelin actually has substantial and broad benefits to health, including an evolutionary sharpening of cognitive functions [1], albeit possibly at the cost of a narrowing of focus to food-related topics. The fast/feast cycle was recently found to recapitulate in humans the improvements in health biomarkers typically observed with caloric restriction, with less detrimental effects on the immune system and bone density [2]. Anyway the line between dietary restriction that improves health and an eating disorder is a fine and dangerous one. The difference is made by meticulously monitoring your micronutrient requirements to avoid any deficiencies. Assuming otherwise optimal nutrition, caloric + protein restriction is consistently associated with improvement in health biomarkers. But long-term human trials with hard endpoints like longevity and suitable controls don’t exist and are impractical. [1] https://pubmed.ncbi.nlm.nih.gov/27993602/ https://pubmed.ncbi.nlm.nih.gov/27993602/ [2] https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30429-2 https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)...
- MeImCounting 3y ago
  There are certainly complicated physiological effects caused by fasting however the heterogeneity and limited number of studies make it difficult to draw definitive conclusions Mental deficits are associated with fasting across a review of a variety of studies https://pubmed.ncbi.nlm.nih.gov/34595721/ https://pubmed.ncbi.nlm.nih.gov/34595721/ Fasting can also cause other mental issues: "Additionally, fasting was found to be associated with alterations in mood, including worsened mood, heightened irritability, difficulties concentrating, and increased fatigue, as well as an increase in depressive score in mentally healthy humans" https://www.nature.com/articles/s41598-022-11639-1 https://www.nature.com/articles/s41598-022-11639-1 All in all it remains highly suspect that fasting has anything but long term and short term negative effects. As I said in another comment it makes sense to me that so called "health fasting" tends to be more common among people who are already vulnerable and at risk for disordered eating. I will continue to spread awareness about the link between "health fasting" (as well as other health and diet based fads) and actual life threatening eating disorders. There is a huge lack of research into eating disorders generally and even less research into the interaction of health fads and eating disorders. I encourage everyone to advocate and support any and all research in this area to combat misinformation spread by "health" gurus and companies looking to make a quick buck.

nerdponx 3y ago

2-5 day fasting seems extreme. I think most intermittent fasting recommendations are more like "skip lunch 3 days a week".

xboxnolifes 3y ago
Usually it's more like skipping breakfast and not snacking after dinner. Skipping lunch isn't much of a fast if you're eating breakfast at at 7am and dinner at 7pm. But eating dinner at ~7pm and having your next meal be lunch is ~16 hours without eating.

giraffe_lady 3y ago

I don't encourage people to fast but it's also not true that it's unsupported by evidence. It's an ancient and widespread practice in nearly all of the major world belief systems. Billions of people fast, and there is a massive cross-cultural body of writings about the effects of it. Which is not the same as modern peer-reviewed medical study, no. But it's not "no evidence" either.

MeImCounting 3y ago
https://clindiabetesendo.biomedcentral.com/articles/10.1186/s40842-023-00152-7 https://clindiabetesendo.biomedcentral.com/articles/10.1186/... https://centerfordiscovery.com/blog/the-dangers-of-intermittent-fasting/ https://centerfordiscovery.com/blog/the-dangers-of-intermitt... I take the stance that health fasting is vastly different in effects from fasting as a religious observance. For instance the frequency and duration of so called "Health fasting" among other factors including the fact that "health fasting" seems to self select for people already at risk of disordered eating.
- giraffe_lady 3y ago
  Yeah I think I agree with that. I'm skeptical of fasting outside of a specific tradition and guidance. But don't like to see the value of those traditions dismissed either.

xk_id 3y ago

> Fasting gives you a dopamine dump to give you the energy to find food. The hunger-hormone ghrelin actually has substantial and broad benefits to health, including an evolutionary sharpening of cognitive functions [1], albeit possibly at the cost of a narrowing of focus to food-related topics. The fast/feast cycle was recently found to recapitulate in humans the improvements in health biomarkers typically observed with caloric restriction, with less detrimental effects on the immune system and bone density [2]. Anyway the line between dietary restriction that improves health and an eating disorder is a fine and dangerous one. The difference is made by meticulously monitoring your micronutrient requirements to avoid any deficiencies. Assuming otherwise optimal nutrition, caloric + protein restriction is consistently associated with improvement in health biomarkers. But long-term human trials with hard endpoints like longevity and suitable controls don’t exist and are impractical. [1] https://pubmed.ncbi.nlm.nih.gov/27993602/ https://pubmed.ncbi.nlm.nih.gov/27993602/ [2] https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)30429-2 https://www.cell.com/cell-metabolism/fulltext/S1550-4131(19)...

MeImCounting 3y ago
There are certainly complicated physiological effects caused by fasting however the heterogeneity and limited number of studies make it difficult to draw definitive conclusions Mental deficits are associated with fasting across a review of a variety of studies https://pubmed.ncbi.nlm.nih.gov/34595721/ https://pubmed.ncbi.nlm.nih.gov/34595721/ Fasting can also cause other mental issues: "Additionally, fasting was found to be associated with alterations in mood, including worsened mood, heightened irritability, difficulties concentrating, and increased fatigue, as well as an increase in depressive score in mentally healthy humans" https://www.nature.com/articles/s41598-022-11639-1 https://www.nature.com/articles/s41598-022-11639-1 All in all it remains highly suspect that fasting has anything but long term and short term negative effects. As I said in another comment it makes sense to me that so called "health fasting" tends to be more common among people who are already vulnerable and at risk for disordered eating. I will continue to spread awareness about the link between "health fasting" (as well as other health and diet based fads) and actual life threatening eating disorders. There is a huge lack of research into eating disorders generally and even less research into the interaction of health fads and eating disorders. I encourage everyone to advocate and support any and all research in this area to combat misinformation spread by "health" gurus and companies looking to make a quick buck.