Fasting for a week:
- Causes significant changes in protein levels across various organs.
- May have health benefits beyond weight loss, but only after 3 days.
- Switches energy source from glucose to fat after 2-3 days.
- Average weight loss of 5.7 kg (fat and muscle), with most fat loss sustained after 3 days of eating.
Implications:
- Provides insights into the molecular basis of fasting’s health effects.
- Paves the way for developing alternative treatments based on fasting benefits.
- Confirms historical use of fasting for specific health conditions.
5.7 kilo in three days? That sounds pretty bad (as in dangerous).
Not to mention these results could provide some very dangerous ideas to those with eating disorders (diagnosed or not). Losing 5.7kg (12lb) in three days sounds insanely dangerous. Going for very long is hella dangerous because you’re not getting necessary nutrition. That’s why there’s a minimum calorie intake for dieting and it is dangerous to go below that.
Yeah as someone who is working on building a healthier relationship with food, this struck me too. It’s absolutely super tempting to lose a lot of weight fast, but I’m firm in my belief that if I want to have results that stick, my attitude towards food needs to change. It’s honestly going really well too.
Since it looks like you didn’t read the article. It’s not a 3 day study. 5.8 kg in 3 days is terrifying but it’s not what happened.
Researchers followed 12 healthy volunteers taking part in a seven-day water-only fast. The volunteers were monitored closely on a daily basis to record changes in the levels of around 3,000 proteins in their blood before, during, and after the fast. By identifying which proteins are involved in the body’s response, the researchers could then predict potential health outcomes of prolonged fasting by integrating genetic information from large-scale studies.
I am genuinely glad to hear that! Because I know it is really hard (from experience; still working on it)
I’ve a feeling it’s probably a thing that one will have to remain cognisant of indefinitely. I’m just glad it’s a fucked up relationship with food rather than something like a sugar addiction, because that seems really tough to handle. Best of luck to us both, I’m sure we can do it! 🥳
Yes we can!
Medical professional here. This is crazy. This is starving your body, I do not recommend.
But what about the potential health benefits?
The body believes it is starving after 24 hours and begins to eat itself. The risks far outweigh the benefits. Have to lose weight the real way, diet and exercise.
Damn it.
Researchers followed 12 healthy volunteers taking part in a seven-day water-only fast. The volunteers were monitored closely on a daily basis to record changes in the levels of around 3,000 proteins in their blood before, during, and after the fast. By identifying which proteins are involved in the body’s response, the researchers could then predict potential health outcomes of prolonged fasting by integrating genetic information from large-scale studies.
Researchers followed 12 healthy volunteers taking part in a seven-day water-only fast. The volunteers were monitored closely on a daily basis to record changes in the levels of around 3,000 proteins in their blood before, during, and after the fast. By identifying which proteins are involved in the body’s response, the researchers could then predict potential health outcomes of prolonged fasting by integrating genetic information from large-scale studies.
The article says it was “fat and lean mass” not water weight. And while the “lean mass” (which I guess could be water) retuned after eating again, the “fat mass” did not.
You will drop a bunch of water at the start if you are eating carbs beforehand because of the water holding the glycogen in your muscles. As you use the glycogen the water holding it also goes, so it isn’t fat loss, just water weight.
The volunteers lost an average of 5.7 kg of both fat mass and lean mass. After three days of eating after fasting, the weight stayed off – the loss of lean was almost completely reversed, but the fat mass stayed off.
Yes, correct, so a smaller portion is fat loss but not the full 5.7kg average. I should have been clearer, they did lose a meaningful amount of weight and it does seem to be beneficial, but it is not 5.7kg of fat loss per person on average, it is a loss of 5.7kg average mass with a portion of that being actual body fat.
Right, that makes sense.
Wait you mean no water? Don’t you die of dehydration? That doesn’t sound good.
Water weight. You still drink water when fasting.
No no, they are saying that you’ll lose a bunch of water weight. As far as I know you generally regain that quite easily once you start eating again.
Personally I subscribe to the idea of calories in < calories out. Sustainable weight loss requires good habits and a healthy relationship with food.
There’s a lot of data that shows that restricting calories causes your metabolism to lower. Fasting basically causes your body to shift to using fat stores, so it still does have adequate fuel # and your metabolism doesn’t fall the same way. It also changes your insulin response, and insulin resistance is one of the reasons you put on weight to begin with. If you’re interested, Dr. Jason Fung has written a couple good books on.the subject. He’s also put out a bunch of YouTube videos on it.
I’ve beef doing intermittent fasting for a while, and you do drop a good amount of weight very quickly. Most of it does stay off, but the idea is that you continue to fast periodically for weight management, typically limiting food intake to only a few hours daily.
Causes your metabolism to lower while you’re restricting calories, or potentially for good?
I ask because I ended up doing this pretty drastically for a time (long story, not proud of it) but once I started eating “normally” again, could my metabolism speed up again?
My understanding is that severe shifts in calorie intake vs output can lead to lasting metabolic changes. I think the main example people point to is that all “biggest loser” contestants failed to keep their weight down even when they maintained their diets and exercise for a long period.
It’s not really metabolic per se, but hormonal. Hunger is hormone driven. If you restrict calories, you recalibrate your hormonal response to fullness and hunger.
I’m certainly not an expert, but my understanding is that the effect from restricting calories can last longer than the restriction. But it can increase again, and there are many other factors that affect the metabolism. Just like slowing if you don’t have many calories it can increase if you have more.
Thanks!
I think that’s for the whole week, but even then, it depends on the person’s weight to begin with.
Looks like it’s 5.7 kg loss in a week, the weight loss is sustained after resuming eating for 3 days
Researchers followed 12 healthy volunteers taking part in a seven-day water-only fast. The volunteers were monitored closely on a daily basis to record changes in the levels of around 3,000 proteins in their blood before, during, and after the fast. By identifying which proteins are involved in the body’s response, the researchers could then predict potential health outcomes of prolonged fasting by integrating genetic information from large-scale studies.
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I can’t imagine not eating for three whole days. I’d be a groveling mess switching between begging for food and raging at every little thing. How do people do this comfortably? Atleast without breaking the china?
Is there a way to train yourself vis a vis slowly building tolerance or something?
Hunger is entirely a hormonal thing. It’s basically a form of anxiety your body induces to make you want to eat. After about 18 hours without food your body switches itself into different hormone state where you just don’t experience hunger the same way.
I have done it quite a few times its actually not that bad. The first 24 hours is usually the worst and then the hunger goes away most of the time. You get reminders that you are hungry but it doesn’t last. Its no where near as bad as people think it is from the first hunger pangs you just have to get over that initial hump.
The biggest secret to losing weight is literally to just be hungry. Once you feel hunger, that’s your body telling you that you are running a calorie deficit.
I wish I had started fasting sooner. When you got for a few days without food it really puts that grouchy kind of afternoon hunger into perspective. I used to feel anxious about where and when I was going to eat, whether or not I was hungry. Now that i’m comfortable with going without food for days i’m just totally unconcerned about it.
It’s like having a super power. I remember being stuck in the Santa Fe airport in the late afternoon waiting for my massively delayed flight to arrive. After three hours or so, it’s past dinner time and people start becoming unglued. One family even has pizza delivered and manages to convince airport security to run it through the security gauntlet for them. I had been fasting for awhile so I was fine, where a year prior I would have been scrambling for food with the rest of them.
Exactly. Even if you plan on eating, just the ability to stretch that for a couple more hours till everyone else isn’t hungry at the same time is huge. Even if people have no plans or reason to fast for health, as long as they can do it safely they should try, just for their own peace of mind.
I was shocked when my doctor suggested intermittent fasting, but having done one meal a day for a while it was only a tiny bit more difficult when I did my 5 day fast. It’s just so freeing to realize that I can go for days without eating with basically no ill effects. It really does reinforce that, if you’re a bit overweight like I am, 3 meals a day, even if they’re healthy, is a luxury I don’t need. To day nothing of the horribly unhealthy food i’d like to be eating.
Even more, it’s helped my relationship with food. I used to worry about the ‘healthy’ option that would still fill me up. In a restaurant that just doesn’t exist. Well, if there isn’t one, I just won’t eat. Or I’ll sit down to a 3000 calorie meal with zero guilt because i’ve either not eaten for long enough that it’s a reasonable intake, or I can just not eat later. It’s really taken a lot of food related stress out of my life. Of course, I see how that could be bad for people with certain types of relationships with food, but it’s helped me immensely.
Yeah… At one point I forgot what that feeling was. Was just a weird feeling, “what this?.. Oh wait… Dude this is ‘hunger’ wtf?!”
Needless to say, I’m overweight again.
You could do what I just did and get a horrible stomach bug that leaves you in bed for four days dreading the thought of food and barely able to suck down half a glass of water! -5/10 would recommend active effort to avoid.
RIP myself, silver lining though lmao
Edit: I did lose ~10lbs though likely a fair amount is water weight
It really isn’t a big deal. You do think of food, but after the second day it’s not like you’re hungry. If you start by intermittent fasting, eating one meal a day, or reducing carbs it makes it a bit easier. Honestly, I find scheduling fasts around family gatherings, etc. much more difficult than being hungry.
The only time I’ve gone that long without eating was when I was stressed beyond belief. It was excruciating and I cannot imagine doing that willingly.
Y’all need to read. NlThis was not a 3 day study:
Researchers followed 12 healthy volunteers taking part in a seven-day water-only fast. The volunteers were monitored closely on a daily basis to record changes in the levels of around 3,000 proteins in their blood before, during, and after the fast. By identifying which proteins are involved in the body’s response, the researchers could then predict potential health outcomes of prolonged fasting by integrating genetic information from large-scale studies.
Anything but diet and exercise
I mean, not eating is a diet? This seems to be directly addressing one part of that equation: you don’t even ‘need’ exercise for simple fat loss. Though of course an actual balance you can keep up perpetually is much better, but this definitely directly touches diet.
I can agree with that. Seems unsustainable to me though.
I’ve heard on quite a few shows that exercising doesn’t actually do much for losing weight. It’s healthy for you but not a good way to lose weight, apparently. Pretty interesting.
I lost 60lbs by sitting on my ass playing video games, counting calories (1500-1800 + one cheat day per week).
Agreed. You can’t outrun the fork, however good habits stack on each other and there’s a lot to be said about mental health benefits. They tend to go hand in hand.
I can’t imagine human diets used to be as predictable as they are now, especially in winter. Attempting a diet that includes fasting doesnt seem unreasonable as part of a larger plan.
At least we now get to decide when to stop fasting :)
Doctors will recommend fasting, or at least intermittent fasting, for a variety of conditions. Particulaly it helps you deal with insulin resistance, which isn’t just diabetes. It could be why you’re carrying a lot of weight, and it could also have to do with anxiety.
‘Diet’ and exercise don’t always work for everyone, or for all problems, and insisting that it does really damages the people who have legitimately put a lot of effort into both those things without seeing meaningful results. Not only do they not see benefits from their hard work, they also start to feel like they’re just not doing enough even if they are.
You should really look into some of the actual science behind fasting, and also behind caloric reduction and exercise before you criticize it so dismissively.
CICO is science.
Yeah, we’re aware that the laws of thermodynamics must be followed. The study clearly showed that if you set CI to zero, and CO remains nonzero, you lose weight.
CICO is science, but your CO can change based on your CI and there are cases where it’s very hard to keep CI down. For an example, I have ADHD, it’s legitimately extremely difficult to keep track of what I eat, eating one meal a day was about the only thing that helped. I believe I was also prediabetic (based on my glucose levels before my weight loss) and eating a small meal, particularly if rich in carbs, made me go hangrryyyyyyy later, but in a fasted state I was completely OK. Now I’ve lost something around the neighbourhood of 30 kilos/65 lbs and don’t need to do one meal a day anymore, because I feel sated from much less food AND stay sated way longer.
This is why different people need their different tricks for weight loss. Find out how to reduce your hunger first and foremost, then focus on actually reducing calories. If fasting leads to being able to handle caloric restriction, it’s awesome. If not, try something else. But don’t restrict calories in a way that makes you continuously feel hungry, because that just won’t work long term.
