Study on 37,545 people reveals that a 14 hour period of fasting improves hunger, mood and sleep

665 points by giuliomagnifico 2 years ago on reddit | 58 comments

John-Footdick | 2 years ago

I saw a large increase to my Heart Rate Variability (HRV) when I started intermittent fasting a couple weeks ago. I no longer snack or eat after dinner and my HRV has gone up and seems to be more stable.

https://www.reddit.com/r/Garmin/s/nLj9kEAqHM

psirjohn | 2 years ago

Everything in biology only makes sense when it can be viewed through the lens of evolution. This study just confirms that. We evolved with long periods of fasting because food wasn't constantly available. It makes sense that our general functioning is improved in those circumstances.

Dogcatnature | 2 years ago

We were not designed to eat 3 full meals a day.

Kracus | 2 years ago

No but our ancestors wished they could, hence our predicament.

I wonder if some day our bodies would mutate/evolve to function better with 3 meals a day?

gjklv | 2 years ago

So what are we going to do to fix it?

gid_hola | 2 years ago

gee i dont know, maybe not eat 3 meals a day? This isn't exactly rocket science

zangrabar | 2 years ago

True. We are still optimized for hunter gatherer type living. It could take a million years before we are optimized for office work unless we force it with science.

TBSJJK | 2 years ago

It doesn't make sense that our functioning improves without food.

INToxicated47 | 2 years ago

Why

thing188 | 2 years ago

Why not? There could be metabolic pathways/mechanisms that are beneficial and are only active during a fast. If some condition (fasting) were present throughout our evolutionary history, it makes sense that some mechanism would evolve that exploits it.

Lothric_Knight420 | 2 years ago

Try it and see for yourself. You’ll be surprised

uzu_afk | 2 years ago

Its not without food. Its without food for a longer period of time. Its also not saying you are starving or losing a lot of weight or anything like that either.

zangrabar | 2 years ago

But it does make sense. The first easy one, digestion takes a lot of energy, packing on weight for survival might be more efficient close to that meal timing too. When we need to hunt for more food, it would make sense we utilize slow burning fuel instead,and enhance our senses so we are more likely to survive. The way we live now is still so new to our biology, we haven’t had enough time to adapt to this. Agriculture has only been in full swing for about 10k years which is a blip in our history. Our bodies are more hunter gatherers than it is office worker optimized. It might take a million years to get to that unless we use science to force it in the coming decades. But today we are still optimized for hunter gatherer. A lot of things start making sense when you think of it from that perspective.

wiser_time | 2 years ago

14 hours of fasting does not improve my mood.

WaycoKid1129 | 2 years ago

You’re not doing it right, go 24 hrs then you’ll feel it

shadowtheimpure | 2 years ago

Makes me grouchy and leaves me with a short temper.

0neM0reLight | 2 years ago

Same here lol. It gives me headaches as well.

an0therblizzard | 2 years ago

As someone who did IF about 6 years ago - and now I am forever changed, I can say that it takes some getting used to.

Nowadays I can go 24 hours with 100-250 calories. Not like I do that often, but occasionally I am traveling and just not in the mood for anything because my hunger just doesn't control me in any way. I can basically tell my stomach to leave me alone. When I feel a headache is coming, I have some nuts or a piece of fruit or something light and then I do one meal a day.

I only wanted to lose like 20lbs, but here I am, 50lbs down and just stays there now. But to begin with, you can't just dive into a 14 hour fast without your body throwing a fit and giving you a headache.

magenta_mojo | 2 years ago

Really? It's not too hard for me. I mean we sleep about 8 hours a day so that's most of the time. That means you can eat between 10am - 8pm. I've been trying 16:8 (fasting 16 hours) so that leaves me with 10am-6pm which is a little early for dinner but doable. I just have to remember to get all my snacks in before then and I'm set for the next day

an0therblizzard | 2 years ago

I am not sure what I said that you are saying "really?" too. What isn't too hard for you?

All that you really did was describe an intermittent fasting schedule.

magenta_mojo | 2 years ago

Replying to you saying it takes some getting used to. I simply described my experience with it, for me it wasn’t too difficult as most of the fasting time is sleeping anyway.

an0therblizzard | 2 years ago

Cool.

And for someone who does not fast at all and eats at regular intervals will probably have a hard time fasting for 14 hours, which represents more than a full day for people.

zangrabar | 2 years ago

I think you misunderstood the timing they mentioned. It’s easier when roughly 7-9 hours that you might be sleeping is half or most of that time. If you stopped eating at 4pm and woke up at 8am,and eat breakfast, that’s a 16 hour fast.

Or if you skip breakfast and stop eating at 8pm and have your first meal at noon, that’s also 16 hours.

It def hard the first few times you do it. But gets easier as you get used to it. I was eventually able to get to 3 days and wasn’t too hard other than work events getting in the way.

Kraken_Kraber | 2 years ago

May I ask what your average energy requirements where/are? My job requires me to be moving constantly and I also work out 3/4 days per week. I can’t see myself only consuming 100-250 calories every 24 hours and expect to be fully functional.

livefreeKB | 2 years ago

Add some salt to you water

Gnarlodious | 2 years ago

Headline says it improves your hunger so at least that makes sense.

aglaophonos | 2 years ago

Intermittent fasting helped me lose 100 pounds. I went from a size 22/24 to a size 4

Zaluiha | 2 years ago

14 hours. Like from dinner at 5:00 - 5:30 and breakfast at 7:30 to 8:00? This is a pretty common occurrence.

sagan999 | 2 years ago

I see you don't do any late night snacking, good for you. Wish it was that easy for me.

use_for_a_name_ | 2 years ago

Or lunch, or second breakfast.

ssp25 | 2 years ago

Bring me the ring

Naphier | 2 years ago

Yeah. I stop eating at 9pm then nothing until noon when I have my fast break. Have done this for years. It didn't significantly change anything. I think most of this is placebo.

SelarDorr | 2 years ago

unpublished, self reported adherence, self reported subjective outcomes.

Zeebuss | 2 years ago

It does align with the findings of previous research on fasting though.

DrDerpberg | 2 years ago

How much of the benefit comes from calorie restriction or more intelligent choices? That's always the hard part when it comes to studies on humans... We do better when you make us think about what we're eating. It's why everything from keto to raw vegan "works" for most people, most of the time.

Does a certain amount of food over 10 hours really have a different effect than the exact same food over 14?

Zeebuss | 2 years ago

>Does a certain amount of food over 10 hours really have a different effect than the exact same food over 14?

Yes, it maximizes time the body spends using stored energy over a constant influx of calories and results in some interesting and potentially very significant health benefits. The effects of intermittent or periodic fasting go beyond just weight loss.

https://www.hopkinsmedicine.org/health/wellness-and-prevention/intermittent-fasting-what-is-it-and-how-does-it-work

ivarsh69 | 2 years ago

Fasting improves hunger 🤯

jadedrealm | 2 years ago

does it include sleep or not

seriousgourmetshit | 2 years ago

Why wouldn't it

zangrabar | 2 years ago

It’s much easier if you do. And doesn’t seem to impact it in a negative way when 8 of the hours are during sleep periods.

saul2015 | 2 years ago

14 is easy, doing 16 now with intermittent fasting

wutchamafuckit | 2 years ago

> For example, if you eat your first bite at 9am, you must eat your last bite by 7pm.

I wonder if this study still holds true for the hours asleep. So if your last bite is at 6:30 PM and first bite is at 8:30 AM would these results still hold?

Illustrious_Bend4982 | 2 years ago

Of course they do that’s how most people fast

whisperwind12 | 2 years ago

Purely anecdotal but I notice that I am hungrier when I eat breakfast than if I had just skipped it. It’s like the act of eating makes me want to eat more. Maybe it’s psychological.

STEVE_THE_JIMMY | 2 years ago

They clearly didn’t test anyone who gets hangry

zangrabar | 2 years ago

Being Hangry is created from the habit of eating 3 meals a day(or just a very strict eating schedule) Breaking habits and consistency can do that to people. New habits can be learned. That also goes to show how important developing strong habits are.

thinkB4WeSpeak | 2 years ago

Of course you're going to get better sleep because you'll be tired from not having calories

--BannedAccount-- | 2 years ago

Bolloxs 14hr fast is not good for you, especially if exercising etc

Zandofkilldof | 2 years ago

And thats why muslims fast for a month

outlier74 | 2 years ago

It improves hunger? No shit!!

Realistic-Dust-3257 | 2 years ago

The amount of people in here asking if this includes sleep is kind of frightening

Cbrt74088 | 2 years ago

So, what are the best times for eating?