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.
Thats because it is.
What you actually want is slow and steady weight loss and sustainable, long term behavioral changes that result in a healthier body fat composition. Losing 10 pounds fast doesnt mean anything good if its all water and lean body mass just to gain it all back later.
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.
Lean mass is generally known as a combination as everything besides fat. So muscle, water, and shit would be my guess.
Yes with a normal diet there is something like an average of 5 pounds of actual shit inside of you. Initial weight loss from calorie restrictions literally happens because there is less poop.
I think that’s for the whole week, but even then, it depends on the person’s weight to begin with.
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.
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.
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?
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!
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.
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.
Looks like it’s 5.7 kg loss in a week, the weight loss is sustained after resuming eating for 3 days
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.
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.
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.
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!
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.