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Intermittent Fasting... the truth?

(41 Posts)
Orlando234 Wed 13-Jan-21 11:24:06

So, I’ve been reading about how IF works.

Some ‘experts’ say you eat less calories as you have a shorter eating window hence weight loss

Others say that after around 12 hours of fasting, your body starts to use stored fat for energy instead of energy from food intake. So if you fast for 16 hours (as I do 16:8) then your body spends 4 hours a day, burning stored fat.

I like the second theory... that sounds like it would work. But reading the first theory blows it for me because I probably eat the same calories in 8 hours as I did when I was just doing a normal calorie controlled diet. I just eat more filling meals (2 instead of 3 in a day plus I stop all snacking during the fast)

Anyone know which theory is correct?

OP’s posts: |
TheStirrer Wed 13-Jan-21 13:18:28

Hmm - I think it depends!! Your body will used stored glucose stores in your liver until they run out before using other sources eg fat & protein so it will depend upon your glucose stores. Hence if you eat a lot of carbs the liver will use those first and you won’t burn as much fat..... however I am not an expert!

TranquilityofSolitude Wed 13-Jan-21 14:33:13

I've decided I don't care how it works because it works for me!

I've been doing it for 18 months now and the difference is incredible. DH and DD (she's 21, so not a child) are also doing it and we all feel much better for it. Over Christmas we went back to eating breakfast for a week as a "treat" but once the novelty of marmalade had worn off we were pleased to get back to it.

bluebluezoo Wed 13-Jan-21 14:47:16

Honestly, metabolic chemistry is so fucking complicated anyone who claims to know how it works doesn't have a clue grin

This new insulin thing- insulin and gluconeogenesis is all finely tuned and it’s harder to mess with than you’d think.

As pp said, it’s about finding a way that works for you. Which tends to be about reducing calories. If that’s cutting carbs, or your eating window, then go with that.

HollowTalk Mon 18-Jan-21 19:45:15

Have a look at Jason Fung on YouTube. He's a kidney specialist and most of his patients had diabetes. He decided to look at curing the diabetes so they could cut down on medication and found that intermittent fasting and low carbing had a huge effect on patients. He's not a believer in counting carbs or counting calories, btw. He says it's such a cheap and effective way of losing weight - other methods, after all, have proven themselves not to work. He's very very convincing.

Hollyhead Mon 18-Jan-21 19:52:41

I think it’s a blend of the two. I certainly think we’ve all been sold a con on ‘needing’ a car by breakfast and it’s making a lot of people fat. When I delay my first meal and make it savoury with protein it really makes a difference to my appetite for the better.

Cormoran Mon 18-Jan-21 20:22:58

I would take Jason Fingerpick with some caution because the majority of the studies he refers to in his book is either cherry picked, twisted or freely interpreted.
Anyone who makes a profit from a nutritional stand or point of view - and at 390 US$ per year subscription I would defend my point of view with teeth and nails - needs to be considered with some scepticism .

Of course, cutting all the rubbish or slow carb (biscuits, crips, snacks , white bread, chocolate) will make you lose weight. Cutting a snacking habit by not eating all day long will make you lose weight.

I live in Australia and here people eat all day long. They carry food in their bag, they eat in the car, they bring food to the playground for the kids, to sport events, and when they are not eating, they are drinking, from massive lattes to smoothies, milkshakes, .... so yes, saying " no"
to anything but water during a certain amount of time will help.

Doesn't matter if you munch on carrots, celery , rice cakes or junk, so many are still munching on stuff even after dinner watching tv, not because they are hungry but out of habit. Giving a program that stops you or justify you not eating might work. But not out of a miraculous biochemical effect, more because of a discipline adults seem to be unable to apply to themselves.

Advising to cut the snaking and cut the junk is not rocket science.

Fat burning in fasting happens in the wind of 16-24 hours, so if you are fasting 16;8 , not much fat burning is happening.

Cormoran Mon 18-Jan-21 21:13:59

Fung obviously and not fingerpick*

Orlando234 Mon 18-Jan-21 22:03:31

Cormoron.
Where did you get the information that fatburning occurs in the 16-24 hour window? I’d like to read about that as I read that it happens after 12 hours ☹️.
This is why I started this thread.... so much conflicting info on IF 🥴🤔

OP’s posts: |
AnxiousWeirdo Mon 18-Jan-21 22:16:32

I did 16:8 - 20:4 (depending on how hungry I was) before Xmas. I absolutely lost weight, I've eaten all the pies since though.

AnxiousWeirdo Mon 18-Jan-21 22:17:42

There's an app called fasting tracker. It tells you what zone you're in and why you're hungry etc etc. Completely free and definitely helped me stick to it

Newt432 Mon 18-Jan-21 22:21:48

There is lots of conflicting advice.

It’s very complex. Reducing calories, snacking and late night eating will result in some weight loss.

IF works over a longer period of time.

Many cultures and religions fast. In Muslims for example fasting in the month of Ramadan does result in some weight loss but it also slows down metabolism which slows down the rate of weight loss.

Fasting in itself has many health benefits and regardless of how much and if you lose weight it can be beneficial.
You may stop eat the same number of calories but for example eating your last meal at 6pm is very different to eating it at 9pm and going to sleep.

Newt432 Mon 18-Jan-21 22:22:42

Still instead of stop

OohImBlindedByTheLights Mon 18-Jan-21 22:27:20

IF has worked for 2 of my friends. Both lost 2 and 3 stone doing it. I want to do it but I honestly can't stand even being slightly peckish at work! I don't know how I'd cope lol!

My friends done 5:2

OohImBlindedByTheLights Mon 18-Jan-21 22:27:52

I type that while drinking a hot chocolate haha

lissie123 Mon 18-Jan-21 22:32:51

I lost weight on 5:2 diet but by god I was starving. I couldn’t think about anything other than food.

HollowTalk Mon 18-Jan-21 23:06:23

Newt432

There is lots of conflicting advice.

It’s very complex. Reducing calories, snacking and late night eating will result in some weight loss.

IF works over a longer period of time.

Many cultures and religions fast. In Muslims for example fasting in the month of Ramadan does result in some weight loss but it also slows down metabolism which slows down the rate of weight loss.

Fasting in itself has many health benefits and regardless of how much and if you lose weight it can be beneficial.
You may stop eat the same number of calories but for example eating your last meal at 6pm is very different to eating it at 9pm and going to sleep.

Jason Fung (or Jason Fingerprick as he is now to be known grin) was saying that a lot of Muslims are fasting during Ramadam but they are getting up early to eat a big meal and then are eating a lot in the evening. If you're fasting to lose weight then obviously that's not going to work.

I think it's pretty obvious that if you're only eating between 12 and 6, then you can only fit in two meals and so you're cutting out a meal at least, and probably a meal and a snack or alcohol.

Cormoran Mon 18-Jan-21 23:26:48

Orlando234

Cormoron.
Where did you get the information that fatburning occurs in the 16-24 hour window? I’d like to read about that as I read that it happens after 12 hours ☹️.
This is why I started this thread.... so much conflicting info on IF 🥴🤔

I have the paid version of the zero app and the timer shows in which body process you are. Plus there are tons of info and videos in the app on the learn section.
If you have a look on medical literature on pubmed and not blogs of influencers , youtubers, podcasters , well anyone making money from their gospel, you will see that it takes at the minimum 12 hours to eliminate the last morsel and then what that meal was will determine when fat burning starts. All agree that it peaks between 16-24 hours

GingerAndTheBiscuits Mon 18-Jan-21 23:29:19

Peter Attia talks about three levers - when you eat, what you eat, and how much. I think he explains it well here, at least in a way that makes sense to me!

www.zerofasting.com/zeros-chief-medical-officer-dr-peter-attia-responds-to-if-study-published-in-jama/

Laufeythejust Mon 18-Jan-21 23:33:03

I think it’s more to do with calories than anything else but I’m definitely no expert. I tried it and I was an absolute nightmare to live with I was so hungry and grumpy!

Newt432 Tue 19-Jan-21 02:29:23

All weight loss and gain is a balance between calories in versus calories used.

@HollowTalk If you’re fasting to lose weight you still have to manage your calories.
And eating two meals in a window of hours is IF - but there’s obviously some differing views about when that window frame is.

Muslims have been fasting for hundreds of years and actually breaking a Muslim fast isn’t about stuffing your face at the two meals but nourishing the body to sustain it through the fast.

Cormoran Tue 19-Jan-21 03:53:58

Marion Nestle in her books and especially in Why calories count shows that any diet, low carb, low fat, keto, will work when it reduces the overall food intake and increase food quality. It is basically up to us to make right choices.

A feeding window filled with high calories ultra processed food is not going to give any benefit be it for weight or health.
Fasting will cut the habit of constant grazing and mindless eating as it makes you more aware of what and when you eat

Bellyflab Fri 22-Jan-21 17:06:31

I have found the 'Delay don't Deny' book by Gin Stephens an amazing resource. Apart from a bestselling book plus a second more up to date one 'Fast, Feast, Repeat' she isn't making any money on it but there is an amazing Facebook support group full of supportive people who follow her intermittent fasting way of life. I love the way she presents the science in a no jargon, easy to understand way. I lost 2 stone following this and although I have put on half a stone (a failure in lockdown to keep my eating 'window' short enough) I have gone back on and think I am losing again

EauDeChlorine Sun 24-Jan-21 18:35:17

I agree. I think Deny don’t delay is brilliant. Great read to stay motivated. I like the Obesity Code also but it is a little longwinded st times.

heLacksnotluster Sun 24-Jan-21 21:36:50

Pre lockdown I lost 2 stone in 3 mths eating one meal a day. The calories I ate snd drank in that meal were well over my tdee (I can eat a lot and love wine). I always exercise so that didn’t change. If i spread out those calories throughout the day I don’t lose weight and probably start to gain even though I workout A LOT.......So for me the science behind insulin and weight gain definitely ring true (only spike insulin (ray) for short periods in the day to allow your body to start to tap into fat stores) As soon as I go back to eating all day. Not only do I never feel full, but I also start feeling crap about myself and gain weight. So back to fasting for me.

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