I rather often fast for a lot longer than 16h; I think the 'day fast' is a pretty rough deal, as the hunger (ie, the down side of fasting) is strongest on the first day. So really a small fast isnt too interesting, as you get all the disadvantage without much in terms of advantages.
By the second day, you are no longer hungry anyway, so, for me, a 3 day fast is next to ideal. But I can do rather easily 5 days.
I mostly start on the monday morning and finish on friday, or saturday if I feel brave and there's nothing too exciting in the fridge!
As to why do do it? Well I like cooking, and eating, and drinking, and I rather hate counting calories and such, I'm much more of a 'on/off' sort of guy, and I rather like a bit of a challenge. That also helps me control my weight, without having to spend stupid amount of time in the gym.
Also, there /is/ a 'high' to a fast, I feel like on the third and fourth day you feel particularly sharper; it then decline a bit and you can feel a bit woozy. But the high is pretty cool...
Day 1 was always the easiest for me, but I had an eating disorder, I was not going about this in a healthy way.
After 3 days, I could easily do a week, and I managed to do a 30 day fast one year.
I don't recall feeling high, I just remember a lot of laying down, dreaming and thinking about food, baking, and not doing much of anything else.
I really rather prefer being able to eat everything I want, and spend 2-3 hours a week at the gym. But my weight has gone up by 10-15 lbs (and I have also aged from 17 years old to 29).
I can't say I'm the same size as when I was fasting, but I have a defined shape, whereas before I was bone and skinny fat.
A 30 day fast sounds pretty insane to me, and quite dangerous without medical supervision. I would like to ask if you were overweight, and the goal was to lose weight?
I had ED-NOS (eating disorder not otherwise specificed) which mostly means it was a combination of anorexia nervosa and bulimia nervosa (which just means binge-purge cycle - fasting counts as purging).
I dropped from 140 lbs to 110 lbs in a month. I'm 5'4 female, and a 'skinny' weight for me is about 130 lbs as I am fairly muscular.
I used to want to look like a skeleton, I had no medical supervision and this was probably one of my worst eating disorder periods, the other being at college where I ate a microwaved apple or orange and 2 cups of broccoli / carrots only every day, for most of my freshman/sophmore year.
When I was ill, I knew I what I was doing with a disorder in mind, but I didn't admit it to anyone outside of me. I think most people who have an eating disorder know they have it inside, it's just something kept carefully secret.
I've been in recovery for about 2 years now, with healthy thoughts and no food restriction, excess exercising, starvation or purging. When I was sick I really didn't care if I died, as I have major depressive disorder comorbid, which I continue to have more difficulty beating than I did the eating disorder. I've fainted from fasting and I've been hospitalized from starvation. It's hell, pretty much.
I think it's important to take a step back from whatever the goal of these diets are, and look at the bigger picture. My weight only varied between 30 lbs over 15 or so years, and it controlled me entirely. It made me have to put a lot of my life on hold, when I had to focus what little energy I had towards getting better. I would really recommend anyone take a more careful, therapeutic look at their life if the above sounds tempting, and they find themselves going into cycles of fasting and 'losing' control over how they manage their diet.
How the hell do you keep up calorically? I'm interested in IF but I am trying to reconcile it with my daily caloric needs. If I didn't eat anything M-F I would be 13,000 calories behind, and in really rough shape. I already struggle to keep on weight as it is.
Well I suggest you don't try then; I'm in the reverse situation, it seems like I can store energy (fat) very efficiently, and also build muscle incredibly quickly. So this 'diet' or lifestyle is quite suited to me, but I think I'd be careful if I were in your case...
For example my wife can eat is a notch over 5 foot tall, and eat as much as I do, and does not put on weight, however, if she misses a meal, she gets wobbly and dizzy. So fasting is definitely not for her!
I have a pet theory that some people are just very good at extracting energy from food, and some people are very bad at it. Perhaps it's related to a difference in gut bacteria mix or something.
I agree regarding day 2 onwards - the main problem is if anyone else in the house (rest of the family) is cooking, as the heightened sense of smell brings in psychological hunger.
I agree; I try to go out and have a small walk if someone cruel is having curry or anything else strong :-)
Also, I'm lucky that I have a separate 'lab' building where I can go and do some hacking during dinner, most excellent excuse to go spend some time with the CNC or 3d printer :-)
I'm not really trying to do it 'by the book' -- I think it's better that you come up with something that works for you.
Fasting with just water is a bit tough, as you can get a metallic taste in your mouth that is rather disagreeable. So that's my 'fix' for that problem.
1kg of fat would be 9000 kcal. Impressive energy expenditure there. Of course a lot of water weight is lost initially (when fasting or just skipping all carbs) but that rate won't hold for weeks on end.
I thought in ketosis it wasn't energy expenditure, the liver causes fat to break down and pass through your bladder? ... maybe I have that all back to front though :\ Maybe ketones pass through your bladder and they also break down fat cells...
In the absence of metabolic disease, the body breaks down fat to use the resulting energy. Think about it evolutionarily; "there's no food right now, time to jettison my energy stores"?
Ketosis is a pretty weird state brought on by lack of carbohydrates. The liver starts producing ketones, ketones rapidly breakdown fat cells to boost blood sugar.
It is mostly unrelated to diabetes as that relates to insulin response.
Ever been in the middle of a hard workout and noticed that you smell like ammonia? That smell means you are burning protein, probably from your muscles. I have only ever seen this during extended exercise, but the same thing during a fast would be a clear indicator you are burning muscle.
So that's what that is! I used to notice that a lot when I first started cycling aggressively in college. Once I got into better shape it mostly went away. Thanks for the tip.
I haven't noticed any muscle lost -- but then again I put on muscle /very/ easily (a bit too easily actually, I get hypertrophia if I do too much sport).
For energy, it turns out your body /does/ have some to burn, and once you made the switch to burning fat, well, usually there's a nice source of energy... I also wonder if you don't get a small dose of adrenalin in too, which would explain the 'high' you get after a couple of days.. but don't quote me on this..
But as I mentioned, the fruit juice input in the morning does help get the day started. Oh, and the coffee contains some nutrients too, so it's not like I'm totally starving.
As the previous poster replied, it's related to https://en.wikipedia.org/wiki/Ketosis
I don't know if you can really get rid of the taste, I'd be curious to know of course; but you kind of get used to it really.
I personally don't mind taking fruit juice, as it does give a small energy boost, especially in the morning.
Not everyone gets it. Fasting puts you in nutritional ketosis as does ketogenic / very-low-carb dieting. But the metallic taste is usually a temporary and harmless keto-adaptation symptom. The body's ketone production and consumption aren't fully balanced at first for quite a while, during which some people flush out most excess ketones in urine while others breathe out more of them. As you keto-adapt (takes from a week to a few months depending on individual), ketone bodies (a byproduct of fat oxidation) are fully utilized in place of glucose by more and more tissues/cells over time, until balance is achieved.
The metallic taste is excess ketones. If your body is not used to using ketones, some will be excreted in the urine and saliva.
If you really goose your ketogenic metabolism, your body gets better at using ketones and the taste will go away. You should also be sure to eat/drink extra salt during a fast or ketogenic diet due to water loss.
By the second day, you are no longer hungry anyway, so, for me, a 3 day fast is next to ideal. But I can do rather easily 5 days.
I mostly start on the monday morning and finish on friday, or saturday if I feel brave and there's nothing too exciting in the fridge!
As to why do do it? Well I like cooking, and eating, and drinking, and I rather hate counting calories and such, I'm much more of a 'on/off' sort of guy, and I rather like a bit of a challenge. That also helps me control my weight, without having to spend stupid amount of time in the gym.
Also, there /is/ a 'high' to a fast, I feel like on the third and fourth day you feel particularly sharper; it then decline a bit and you can feel a bit woozy. But the high is pretty cool...