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> you can do multiple 24-hour fasts and get the same experience from a health point of view NO, that's incorrect. The length matters a lot. In fact, a major ch
by srik 5y ago
> you can do multiple 24-hour fasts and get the same experience from a health point of view
NO, that's incorrect. The length matters a lot. In fact, a major change occurs after the 2-3 day mark, when body glycogen stores are depleted and your body shifts to ketosis etc. Another major marker has to do with when a much coveted state called autophagy is activated.
- solarmist 5y agoI have not heard this. Can you share more? I’m familiar with ketosis but unfamiliar with it in conjunction with fasting. Or benefits for otherwise healthy people. Ketosis has lots of downsides for normally healthy people. Ketosis is literally the start of starvation, so I'm dubious of widespread health benefits. I know it is extremely beneficial to people with a history of seizures, but that's it.
- brigandish 5y ago> Ketosis has lots of downsides for normally healthy people. I've been considering trying ketosis but all I've heard are good things, what are the downsides?
- solarmist 5y agoThe most significant downsides are psychological and kidney stones, plus its literally (by definition) your body’s signal of starvation. https://en.wikipedia.org/wiki/Ketosis#Safety https://en.wikipedia.org/wiki/Ketosis#Safety Oh and this gem from the article on starvation. > After two or three days of fasting, the liver begins to synthesize ketone bodies from precursors obtained from fatty acid breakdown. The brain uses these ketone bodies as fuel, thus cutting its requirement for glucose. After fasting for three days, the brain gets 30% of its energy from ketone bodies. After four days, this may increase to 70% or more.[11] Thus, the production of ketone bodies cuts the brain's glucose requirement from 80 g per day to 30 g per day, about 35% of normal, with 65% derived from ketone bodies. But of the brain's remaining 30 g requirement, 20 g per day can be produced by the liver from glycerol (itself a product of fat breakdown). This still leaves a deficit of about 10 g of glucose per day that must be supplied from another source; this other source will be the body's own proteins. This is the biggest reason I've never done more than toy with ketosis is the body consuming muscle for protein to supply that remaining 10g of glucose per day. Esp. because 1 lb of muscle only 1,800 Cal vs 3,500 Cal / lb. Fat.
- Zababa 5y agoThere's nothing in the article you linked to support your claim that it's "literally your body’s signal of starvation". It does happen during starvation, but that's it.
- solarmist 5y agoThe first two phases of starvation are defined in terms of ketosis. It is by definition the start of starvation. https://en.wikipedia.org/wiki/Starvation https://en.wikipedia.org/wiki/Starvation Phase one: ... After that, the body begins to break down fat and protein. Fatty acids are used by the body as an energy source for muscles, but lower the amount of glucose that gets to the brain. Another chemical that comes from fatty acids is glycerol. It can be used like glucose for energy, but eventually runs out. Phase two: Phase two can last for up to weeks at a time. In this phase, the body mainly uses stored fat for energy. The breakdown occurs in the liver and turns fat into ketones. After fasting has gone on for one week, the brain will use these ketones and any leftover glucose. Using ketones lowers the need for glucose, and the body slows the breakdown of proteins.
- Zababa 5y agoKetosis being present when starvation occurs does not mean that starvation occurs every time ketosis is present. A in B doesn't mean B in A.
- solarmist 5y agoIt seems we're arguing semantics here. My point is that it is biologically indistinguishable from starvation at this point again by definition. Without an interview a doctor could not tell the difference. Your point seems be an objection to the use of the word starvation because it doesn't progress to the later stages due to maintenance of available fatty acids. And that it can be useful and therefore the word starvation is inappropriate. Does this sum it up?
- 5y ago
- silicon2401 5y agoketosis increases risk of kidney stones, which is a pretty huge downside given that many people describe kidney stones as more painful than childbirth
- brigandish 5y agoThat certainly doesn’t sound fun! Thanks, I obviously need to do more research.
- deleted 5y ago[deleted]
- asguy 5y agoThis has been my personal experience. Things go strongly ketogenic around day 3. It’s an experience worth having at least once in your life, even if you’re not interested in a ketogenic diet. The longest I’ve fasted is 7 days, and things felt quite a bit different between day 2 and day 4.