Insulin resistance after a 3-day fast | Hacker News Reader

Insulin resistance after a 3-day fast

journals.physiology.org

"We show that a 3-day fast results in increases in circulating lipids and insulin resistance in subjects expressing a high or low proportion of type I muscle fibers. High expression of type I is associated with a higher capacity to oxidize lipids and a greater loss of insulin sensitivity after starvation."

Higher triglycerides and lower insulin sensitivity is no bueno right? There are a few youtube health influencers in the minority that have suggested fasting is not good for you long term, including intermittent fasting.

>There are a few youtube health influencers in the minority that have suggested fasting is not good for you long term, including intermittent fasting.

Peter Attia was one of the biggest proponents of fasting, and did regular TRF along with periodic multi-day water-only fasts, but stopped completely after his DEXA scans showed drastic muscle loss, even with regular strength training. Multiple studies have shown that when used as a weight loss tool, it's no better than regular caloric restrictions, and that it actually results in worse body composition, skewing the weight loss towards muscle and away from fat: https://jamanetwork.com/journals/jamainternalmedicine/fullar...

>In this RCT, a prescription of TRE did not result in weight loss when compared with a control prescription of 3 meals per day. Time-restricted eating did not change any relevant metabolic markers. Finally, there was a decrease in ALM in the TRE group compared with CMT. Together, the results of this study (1) do not support the efficacy of TRE for weight loss, (2) highlight the importance of control interventions, and (3) offer caution about the potential effects of TRE on ALM. Future studies should be aimed at understanding the effects of early vs late TRE and protein intake or timing as a means to offset the loss in ALM.

ALM = Appendicular (i.e., limb) Lean Mass.

IF != TRF

> IF: He stopped doing 3-day fasts once per month and 7-day fasts once per quarter.

> TRF/TRE: restricting the daily eating window.

The study I linked to was specifically about TRF. Here's Attia on TRF, where he mentions the reduced insulin sensitivity side effect he sees in his TRF patients: https://www.youtube.com/watch?v=x6wczdlcBtI

I didn’t know that! I did TRF and it helped me reduce my weight but I also noticed a significant muscle loss. It made me a bit worried but I attributed it to my age. Now it seems it’s not simple as that! :’( Should I increase my protein intake and do more strength exercises to gain muscle again?

Stop fasting. It's a meme, just like keto. It's unbelievable how bad HNers are when it comes to diet and nutrition. And if you dare to call them on it, they'll eagerly downvote and flag you.

I believe in the context of cancer suppression (I'll never be able to find the episode again) he stated he would still consider fasting in that scenario.

I thought that fasting brings down your insulin levels or is that what they call resistance by starvation.

https://m.youtube.com/watch?v=RuOvn4UqznU

I eat once a day. An 8 hour window for eating like in this study https://jamanetwork.com/journals/jamainternalmedicine/fullar... is business as usual.

You mean the study where the TRFers lost no more weight than the group eating three meals a day, but did lose a disproportionate amount of muscle? https://news.ycombinator.com/item?id=37192843

This study shows that metobolic markers after fasting are related to physiological differences in the subjects.

The full text can be accessed via https://www.researchgate.net/publication/368542960_Insulin_r...

Here is an auto-generated summary from scisummary.com:

Introduction and Study Design

This scientific article examines the role of muscle fiber composition in the metabolic responses to short-term starvation. The study involved two groups of healthy young subjects, one with a high proportion of type I muscle fibers and the other with a low proportion. The subjects were studied after an overnight fast and after a 3-day fast, which induces insulin resistance.

Impact of Muscle Fiber Composition on Glucose Tolerance and Insulin Sensitivity

The results show that glucose tolerance deteriorated to a similar degree in both groups after starvation. However, whole body insulin sensitivity decreased markedly in the group with a high proportion of type I fibers, while the decrease was smaller in the group with a low proportion. This suggests that loss of insulin sensitivity after short-term starvation is a function of muscle fiber composition.

Influence of Muscle Fiber Composition on Lipid Oxidation

The study also found that the capacity of muscle fibers to oxidize lipids was significantly higher in the group with a high proportion of type I fibers. This indicates that the loss of insulin sensitivity in this group is associated with an elevated capacity of muscle to oxidize lipids, rather than a decreased capacity.

Implications and Future Research Directions

The findings suggest that lipid-mediated insulin resistance may be influenced by the capacity of muscle fibers to oxidize fats. The study provides insights into the mechanisms underlying insulin resistance and the role of muscle fiber composition in metabolic responses to fasting. Further research is needed to fully understand the relationship between muscle fiber composition, lipid metabolism, and insulin resistance.

Yes the key thing here seems to be the influence of type I vs II muscle fiber composition on glucose sensitivity. That more type I would be worse is what I think most folks would expect but still interesting.

Notable that we tend to lose type II fibers as we age[0].

[0] - https://www.science.org/doi/10.1126/sageke.2003.46.pe31#:~:t....

When breaking the fast, start by eating mussels (chromium) to reverse the deleterious effects of fasting on the immune system, and to reverse the carb and lipids dysregulation.

I've noticed that after a 3-day water fast my muscles perform better (after thiamin-initiated refeeding) but my brain is out of whack for a week. Why could that be?

yeah the brain fog thing is what kills me during/after these. can't let it affect my work.

Interesting. I never got brain fog (opposite i have less when fasting/keto). But my brain gets crazy about thinking about food. Not really hungry. Just imagine all the food i could eat.

it depends on how much you do it, i guess. i'm pretty sure i've been overdoing water fasting. Over time, it's been getting harder and harder to concentrate and get anything done after about a day or so, it wasn't like that in the beginning at all. Pretty disappointing tbh, i could deal with any side effects easily, but not this one...

Look up nomind / mushin. Don't anticipate happiness or pain. Enjoy the present moment. I do 3 day fasts easy peasy now.

https://www.youtube.com/watch?v=XeW7jgnf8AY

Extended fasts also seem like they would have beneficial anti-parasitical effects, reminds me of how old monastic traditions emphasized fasting.

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