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.
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: He stopped doing 3-day fasts once per month and 7-day fasts once per quarter.
> TRF/TRE: restricting the daily eating window.
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.
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....
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.
