The FastDay Forum

This a big question for me about this Diet, which I started tuesday.
Reading the book Mr Mosley, has 2 small meals a day 2 days a week, which ends up being 12 hours between meals.
The question is 12 hours enough to kick you body into "fasting" mode?
I know allot of non fasting people who stop eating @ 7pm and don't eat breakfast until 7 am. thats 12 hours without food.

I guess I'm trying understand how this diet works. Is 12 hours without food really enough, or is it more of the 12 hours without food then 300 calories, another 12 hours (body probably burns up 300 cals an hour)then 300 calories and another 12 hours. So its really during those times after the very small meals that the body kicks into fasting mode?

I also am doing my feeding times a little differently. my first feeding is not until lunch @ 12 and my next is dinner @ 7. that means before the first meal I have not eaten for 14-16 hours but then after that meal its only 7 hours until dinner, then 13 hours until my normal breakfast. I'm not sure how effective this is and I do not see any guidelines on how long you need to go with our food to get your body into fasting mode and get the health benefits.

[Moogie]

It's really more of a very low calorie day than a fasting day, although it would seem that the longer the period without food, the greater the health benefits. This doesn't necessarily have much impact on the weight loss aspect though.

You can divide up your calories however you like, whether you're having a several 12 hour fasts (dinner to breakfast, breakfast to dinner, dinner to breakfast), a 16 hour + 12 hour fast (dinner to lunch, dinner to breakfast) or a 24 hour + 12-16 hour fast (dinner to dinner, dinner to breakfast/lunch).

Many of us have a full 24 hour fast followed by a meal of up to 500 cals for dinner on our fasting days. Often on waking up I find I'm not that hungry and won't have breakfast until late morning or lunchtime, so that's another good length of time without food there.

[carorees]

Hi Peteo

I'm afraid that the honest answer is that nobody knows.

The first problem is, how do you define fasting mode? Is it the burning of fats (happens all the time to a greater or lesser extent depending on your glycogen reserve which in turn depends on a host of factors), measureable ketones in the urine (doesn't really indicate much apart from the fact that you are burning enough fat to get a spill over into the urine), increase in growth hormone (GH is produced in spurts so it depends what time of day you measure it), triggering of autophagy (unmeasureable at present)?

The experts that Dr M spoke to indicated that they felt that longer you go without food the better, but no-one was able to say definitively whether 3 x 12 hours is better than 1 x 24 hours plus 1 x 12 hours or any other arrangement. Clearly if you are only eating a relatively small amount of food then the time between eating and returning to 'fasting mode' (whatever that might be) will be shorter than after a big meal.

As we don't know what the health benefits beyond weight loss will turn out to be (they may be massive or nothing or anywhere in between), it is impossible to give any guidelines.

Well, that's not strictly true. To get any of health benefits you have to be able to keep on with it and not give up because you have made life too complicated or uncomfortable, so our main guideline is to try to go a good long time without food on a fasting day but if you keep to the calorie restriction, any meal pattern that fits with your lifestyle and you can keep doing indefinitely is fine.

Many people find that with practice they gravitate to having a longer fasting period and fewer meals anyway so I think you should just go with what works for you for now and once you are comfortable with fasting you can experiment to see if a different meal pattern would be better.

Hmm was worried about this. Really every thing in the book and TV show seems to be unknown..We don't know really if IGF goes down because of IMF, or due to lower protein intake. We do not know if cholesterol goes down due to less calories (and most likely less overall fat & cholesterol intake)same with insulin (probably eating less overall sugar too) So really what are the benefits to IMF over just eating less each day??

It's much easier for me to eat much less some days than a bit less every day for 2 years, to lose the amount of weight I should.

I'm not going to worry about the other benefits (though balance and cognitive things seem to be better) because the excess weight is a higher risk than anything else.

It's much easier for me to eat much less some days than a bit less every day for 2 years, to lose the amount of weight I should.

I'm not going to worry about the other benefits (though balance and cognitive things seem to be better) because the excess weight is a higher risk than anything else.

Do you find it easier to only eat 500 calories 2 days a week then just cutting your calories 200-300 calories a day?

Yep, and I was doing ADF for the first 10 weeks. On 4:3 now.

Cutting my cals by 2/300 a day never resulted in weight loss. Mentally, it's much easier for me as this way fits in with how I live my life.

My weight was pretty static, just at a higher level. Restricting calories every day for 1 or 2 years was impossible as life got in the way, being away from home or whatever so any weight lost was regained. This is much better and very predictable.

Im asking that because the Book & TV show are saying there are other benefits to IMF over just a calorie restricted diet, but as you see on this forum no one really knows if this is true

Yep, and I was doing ADF for the first 10 weeks. On 4:3 now.

Cutting my cals by 2/300 a day never resulted in weight loss. Mentally, it's much easier for me as this way fits in with how I live my life.

My weight was pretty static, just at a higher level. Restricting calories every day for 1 or 2 years was impossible as life got in the way, being away from home or whatever so any weight lost was regained. This is much better and very predictable.

If I may ask, how much weight have your lost?

I was drawn to this diet because I think it might fit my lifestyle better than just calorie restriction and it supposedly had better health benefits that the TV & book talk about (IGF-1 reduction), but I'm still on the fence since I am reading allot, and there seems to be so many unknowns..

[carorees]

Hmm was worried about this. Really every thing in the book and TV show seems to be unknown..We don't know really if IGF goes down because of IMF, or due to lower protein intake. We do not know if cholesterol goes down due to less calories (and most likely less overall fat & cholesterol intake)same with insulin (probably eating less overall sugar too) So really what are the benefits to IMF over just eating less each day??

Just because we don't know precisely what happens when you fast, doesn't mean that there are no additional benefits to fasting. There are certainly indications that fasting brings additional benefits, but we cannot make any guarantees or say how big these advantages might be. Several lines of scientific enquiry suggest that there may be benefits but it will take a time to tease it all out. Most of us aren't prepared to wait for the science to catch up so we are working on the principle that reducing weight is good, it seems like an easier way to control weight for many, and there may be some extra benefits too.

None of us can know whether how we choose to eat will prevent us from getting, say, cancer, because, whether we get it or not, there is no way of knowing what would have happened had we made different choices. We each have to make our own gamble with fate and see what happens!

Hmm was worried about this. Really every thing in the book and TV show seems to be unknown..We don't know really if IGF goes down because of IMF, or due to lower protein intake. We do not know if cholesterol goes down due to less calories (and most likely less overall fat & cholesterol intake)same with insulin (probably eating less overall sugar too) So really what are the benefits to IMF over just eating less each day??

The benefits to me are I find this WOE much easier to handle. As with BBT, cutting the calories every day is fine for awhile but you eventually tire of it. One of two things happens then--you've learned to eat better & continue doing so, or you gain weight back. If you end up gaining weight back your cholesterol, bp, IGF, etc. is guaranteed to go back up. So the benefits to this diet is those hopefully stay lower. It's not a miracle cure-all pill to live a longer life, as Caroline said life happens and health issues come up, but in the present its a good way to be healthier!

[carorees]

as Caroline said life happens and health issues come up, but in the present its a good way to be healthier!

But I didn't put it nearly as succinctly as you

If I may ask, how much weight have your lost?

I was drawn to this diet because I think it might fit my lifestyle better than just calorie restriction and it supposedly had better health benefits that the TV & book talk about (IGF-1 reduction), but I'm still on the fence since I am reading allot, and there seems to be so many unknowns..

Look at my avatar and have a look at my graph and stats underneath.

The benefits for me were immediate - my mind was concentrated by high bp readings, so I had to do something and quick as I was being dragged into the doctor's every 2 weeks. And yes, it's lower and I don't have to go back for 6 months.

I'm one of the lucky ones who feels better for fasting with more energy. It's also helped my relationship as my OH knows exactly when I can eat (if he sees me with chocolate) and that I'm not cheating. He's lost weight too, without trying, just from the change in diet and is now 157lbs at 6 ft tall.

The human body depends on incredibly complex and delicate systems, so I confess I'd never really expect a complete account of it. Or to understand a complete account - I have problems just understanding the functions of insulin!

I have to depend on specific and vital facts: (1) I've been overweight for about thirty years, only once managed to take weight off, and regained it. (2) I have lost about a stone with the fasting diet. (3) I find long-term constant dieting more or less impossible. (4) I find two days a week with only 500 calories quite manageable (rather to my surprise!). (5) I have type 2 diabetes, so without imagining other health problems, I have a serious disease which I can do quite a bit about.

I would be most surprised if this WOE didn't have measurable benefits on a person's health (what happened to Michael Mosley's blood glucose, for example, was very instructive). And in the meantime I'm really glad to have found a WOE which suits me and which I can imagine maintaining for the rest of my life.

Thanks to everyone who's contributed to this forum. Special thanks to Moogie and CaroRees

Hmm was worried about this. Really every thing in the book and TV show seems to be unknown..We don't know really if IGF goes down because of IMF, or due to lower protein intake. We do not know if cholesterol goes down due to less calories (and most likely less overall fat & cholesterol intake)same with insulin (probably eating less overall sugar too) So really what are the benefits to IMF over just eating less each day??

Just because we don't know precisely what happens when you fast, doesn't mean that there are no additional benefits to fasting. There are certainly indications that fasting brings additional benefits, but we cannot make any guarantees or say how big these advantages might be. Several lines of scientific enquiry suggest that there may be benefits but it will take a time to tease it all out. Most of us aren't prepared to wait for the science to catch up so we are working on the principle that reducing weight is good, it seems like an easier way to control weight for many, and there may be some extra benefits too.

None of us can know whether how we choose to eat will prevent us from getting, say, cancer, because, whether we get it or not, there is no way of knowing what would have happened had we made different choices. We each have to make our own gamble with fate and see what happens!

I understand that we can't know everything. But whether this is really fasting is a BIG unknown.. The benefits might just be from calorie restriction, and might not really include any additional benefits you would get if you were fasting. (if there are any)

I guess I am saying that
1) we know we are reducing calorie intake
2) seems to cause weight loss in most people
3) you are getting most of the benefits you would see if you lost weight in another way

and thats all we know. There does not seem to be any consensus on additional benefits that IMF might provide, so in reality this just like any other diet, but maybe easier to follow for some people.