Long term waterfast

Surprised to see the question on WSO btw. I didn’t know there were my-kind-of-crazy people here.

TLDR: long-term water fasting (LTWOF) is NOT a solution for weight loss, and I no longer do them. I have had my best sustainable weight loss on OMAD / IF. I find the 16:8 / 18:6 to be too wide an eating window for weight loss. I also make sure I’m not eating too close to dinner time – so better you keep an early eating window. I know a lot of folks in the IF crowd skip breakfasts for convenience sake, and I often do this as well, but truth be told it’s dinner one ought to skip for weight loss. An early / mid-day OMAD or 2meals/day work better than an IF eating window.

Resources to Google/Youtube: Dr. Jason Fung (wrote a good book on fasting), Dr. Michael Greger (wrote a good book called How Not to Diet, and also has some good YT talks about timing of eating to maximize weight loss), Dr. Alan Goldhamer of True North Center (big fasting advocate, runs a center in CA for the purpose).

The problem with LT water fasting (>3 days) is that your body drops its metabolic rate after a few days to prevent weight loss. Ironies abound. Dr. Jason Fung, whom I am sure you’ve also looked into, also talks/writes about this. Also from a safety standpoint you really shouldn’t be doing more than 5 to 7 days of water fasts without medical supervision, depending on your fat reserves. Thirdly, from a productivity standpoint I also really struggled because I find it very difficult to work during a fast.

So let me tell you what happens from a physiological standpoint. I did body scans and bloodwork on all my fasts so I can pass you the stats. You absolutely do not lose any muscle during a fast. In fact, fasting forces your body to boost HGH so you actually gain muscle (albeit lean and ungycated muscle) during a fast. There are actors (like Hugh Jackman when training for Wolverine) who went on crazy weightlifting regimes + LTWOF in order to boost HGH and get a pumped up for the role. Your body is engineered to preserve muscle and burn fat during a fast, so it has multiple mechanisms to retain muscle and during full fast-induced ketosis, and HGH boosting is just one of the mechanisms.

What happens during a fast is:

• • First 12-15 hours > your body is burning glycogen as its normal power source, primarily from your liver. This is your normal day routine.
• • After about 12-15 hours your body switches to ketosis, and burns fat for energy. That’s why intermittent fasting works. You are finally digging in to those fat reserves. That’s why for me OMAD or 2meals/day works well. When I was doing an 18:6 or 16:8 I.F. the window was just too wide to make any real progress in fat burning. Your maximum fat burning is at this point.
• • The first 3 days of LTWOF is a motherfucker. This is the hardest part of the fast. I get irritable and hungry as hell. Moreover because fat is harder to burn than glycogen, your body also burns the glycogen stored in your muscles. Your muscles then deflate, and you become more lean looking. Your face becomes leaner looking. You feel exhausted and sore all over, because of the glycogen depletion in your muscles. You needn’t worry though, because your HGH is boosted, so once you eventually start eating again, your muscles re-inflate and you’ll actually come out with slightly higher muscle mass. I can send you Excels of what happened to my body during this phase. Fascinating stuff.
• • After day 3 the body is in full ketosis, your glycogen is pretty much all depleted, and your body shuts off the hunger and goes into a restive state. Your digestive system hibernates. This makes the rest of the fast MUCH easier. Day 3-5 or 3-7 (your mileage may vary) is actually quite easy and pleasant. You’ve no hanger, your thoughts are crystal clear, you only need to sleep 4 hours/night because your body is not exhausted from digestion. This is a very meditative phase. This is why many religions actually practices some fasting because it really gives your body a chance to rest, heal, and your mind a chance to relax and focus at the same time. Your body starts to heal little things. Your skin clears up and takes on a pleasant glow. I had minor scars clear up. Dry skin clears up. You’ll also likely have a single big watery BM which is your system discharging what poop/food remains is in your digestive system, and is likely flushing out other pollutants. You will start losing about 1lb/day in fat. Once you do start eating eventually, your muscles reinflate, your body is healthier than when you started.

My personal experience:

• • At around day 7-10 things started to get a bit challenging. I experienced headaches from mineral deficiencies. I was still only needing to sleep 4 hrs/night and had good thinking capability, but the headaches bothered me. I was able to patch this over by drinking NoSalt – a salt substitute made of magnesium phosphate and a bit of pink Himalayan salt. This cleared all the headaches and I was able to go to 15 days. I did two 15 day fasts (they were about a year apart) and then the next year I pushed myself and did 28 days (technically not the 30 days I had aimed for).
• • I experienced mental hunger during the fast after about 10 days. This is different than physical hunger. Your digestive system is shut down already, and your body isn’t producing the hunger-triggering hormones. But after about 10 days you start to really miss food in your mind. I found myself wandering around the grocery store, gazing longingly at bright fruits. You miss the idea of eating and the sweetness of fruits or the tastes of veggies and starches. But your stomach is asleep. Your mind though has this longing.
• • I found it nearly impossible to work during the fasts. Others have been able to work, and actually find it distracts them from the mental hunger.
• • In each case, my weight came back after ending the fasts. Like, to a tee. I started at X, then lost 1lb /day during the fast, and then once I started eating eventually I got precisely back to X again. It’s amazing – but not the result I wanted. On OMAD or 2meal/day the weight loss is more sustainable and maintainable.
• • If you DO decide to LTWOF (I don’t recommend LTWOF anymore) then start by first going to a very clean all veggie diet first for 3-5 days prior to starting. This clears your digestive system of heavier foods and pollutants. On the day of your fast’s start I recommend you do a crazy exhausting HIIT workout or long-distance run. This will help burn your liver glycogen before you start fasting and shortens your window to ketosis. It makes the hunger pangs shorter. Now, as far as exiting the fast, you want to do this gently. Many fasting centers serve their clients watermelon and veggie broth for 2-3 days before weaning them back on to softer steamed veggies. This is a way to gradually get your digestive system woken up and back to eating foods.