The FastDay Forum

I have been meaning to try the 5/2 diet ever since seeing the programme in August.

Anyway, I started yesterday - Monday 14th.

Last actual food was a good bowl of soup / plenty of bread on Sunday 13th. lunch time, plus most of
a bag of M+S 'extra chocolatey' caramels ( judging by the delicious taste each one
represents about 500 cals I think ).

So yesterday - Monday - no food at all - just a cup of tea in the morning ( w skimmed milk ) : then nothing all day.

Today - Tues 15th - as at this writing just the tea and the hope / intention to eat
nothing all day. [ MAybe it's tempting fate to write before tomorrow.....]

For me I think this is actually easier than counting 600 cals or whatever.
The way my mind / stomach works is that one extra-chocolatey caramel means the whole
packet / one glass of wine means the whole bottle.

For what it's worth I don't even really feel hungry ( ok that could change over next
12 to 15 hours ).

Any medical or other reason why a person can't go 48 hours non stop fasting on a regular basis ? [ I do, after all, if it has anything to do with the way camels work,
have about 6 months of resource stored in the grobesity - incarnate stomach. ]

For info:

6ft tall;
17 stone; [ Absolute ALL of the excess weight is around the stomach - yuck ! ];
44"-46" waist
61 yrs.

WOULD LIKE to be 12 stone and 32" waist. [ I've kept some of the clothes from
36" waist against the day when....... ).

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3017674/ reports use of calorie restriction on two consecutive days. A lot of the published work is on alternate day fasting.

From the Horizon program I think Michael originally looked at 2 consecutive days of fasting but a) couldn't hack the full fast and b) preferred to split the days. My recollection is hazy though. http://www.bbc.co.uk/news/health-19112549 suggests he turned the alternate day total fast into two days calorie restriction.

Part of my reasoning for wanting to see if I can hack the full two days x zero
cals intake is that my understanding [ admittedly possibly imperfect ] of the
theory underlying the benefits of intermittent fasting is that after a certain period
of time w/o food the ?liver starts to burn fat rather than muscle [ or some other
metabolism - beneficial stuff happens, I forget what exactly ] ; so I am guessing that if this
is the mechanism by which the benefits ensue, then it is more likely to take place
sooner rather than later if the beneficial mechanics are not interrupted after
24 hours by a return to eating ?

Any science based comments on this layman's reasoning ?

There's only about 5g or 20 calories of sugar in your bloodstream, and you probably burn about 80 calories an hour doing nothing, so if no food comes in from eating or digestion then your systems turn to your fat reserves for energy.

This is what you want, as using up your fat reserves id the way to lose weight.

So your liver will convert fat to glucose to maintain blood sugar levels above a minimum value and your muscles (inc the heart) will use fatty acids released from fat cells, these processes go on all the time but once you have used up your short term glycogen reserves they are the only way your body gets its fuel.

So I would agree with your thoughts that a longer complete fast will have more impact than separate days and also more impact than 500 calorie days. A well known case of an obese Scotsman about 40 years ago showed how you can fast for over a year and survive, with minor medication to correct deficiencies in potassium etc from time to time.

[carorees]

I am not sure the science is sufficiently advanced to answer those questions.

Actually PhilT has missed out that before you start burning fat as fuel (gluconeogenesis, aka ketosis) you have to use up the glycogen reserves which takes a long time.

It seems that although the 2 non-consecutive days are unlikely to result in the body entering ketosis (though that depends so much on the person and their diet), fat burning still takes place.

The fact that reducing IGF-1 is beneficial is known but how low and what is the best method is unknown. We do know that Dr M reduced his IGF-1 by around half using non-consecutive calorie restriction.

As far as benefits in terms of stimulating production of brain derived neurotrophic factor (BDNF), which helps with Alzheimer's and memory problems, it seems that alternate day fasting does promote BDNF as do ketone bodies so whether some ketosis occurs or whether there are two mechanisms is not known.

From what I can see, the time taken to enter ketosis during a water only fast is around 48--72 hours for men but some people seem to be able to switch into ketosis much faster and it seems that low carb diets and lots of exercise can do this.

It seems to me that fasting for two days in a row on 25% of your normal calorie needs is unlikely to result in ketosis but will bring at least as many benefits as non-consecutive fasts. Whether you get an additional benefit from doing the two days consecutive no-one knows.

The bottom line is, if you find it easy and convenient, why not try it, but if it is difficult and inconvenient, go for non-consecutive days! Everyone needs to find their favoured way of incorporating fasting into their lives.

One last point, some people may have medical conditions making a 2-day fast inadvisable, so this is not an approach we should be recommending to all I feel. The study quoted by PhilT was in otherwise healthy young women (i.e., they were obese but had no other health problems).

[carorees]

I was just reading through the research paper that PhilT kindly posted a link to. I came across this little nugget:

"A sub-set of women (15 IER and 9 CER) provided fasting serum samples over 1 week during the study period. The IER group demonstrated acute reductions in fasting insulin (−23%), HOMA [insulin resistance] (−29%) and triglycerides (−18%), in the morning after the 2 day VLCD which normalised within 2 days of resuming normal diet. There were no significant changes in the CER group"

The fact that the changes normalised within 2 days suggests to me that there may be benefits in splitting the fast days. Fasting insulin levels and HOMA are measures of insulin resistance which is associated with type 2 diabetes, obesity, cardiovascular disease etc.

Also, the group did not show significant changes in IGF-1 and I wonder whether following a normal (growth promoting) diet for 5 days in a row compensated for the gains during the 2 day fast. When Dr M did a 4 day fast he got a big drop in IGF-1 but was told that levels would soon return to normal.

Just throwing these thoughts in to create more confusion!!

Actually I said "once you have used up your short term glycogen reserves they are the only way your body gets its fuel"

Glycogen in the liver is about 100g so 400 calories or a few hours worth. Glycogen in muscles can only be used by those muscles but the quantity is greater than that in the liver (which can be used anywhere).

"We studied 107 premenopausal women aged 30 to 45 years with adult weight gain since the age of 20 exceeding 10kg, and a body mass index (BMI) between 24 and 40 kg/m2" doesn't sound like "healthy young women" to me but I agree with your sentiment and note that the majority of clinical trials avoid people with other significant diseases.

The fact that the changes normalised within 2 days suggests to me that there may be benefits in splitting the fast days.

My reading of Figure 3 is that it took the two consecutive days to drop the insulin sensitivity as much as it did and two days to recover, so we can't extrapolate from there to say it would be better to have half the effect twice a week ?

The finding that "Neither IER nor CER led to appreciable changes in total or free IGF-1" does contradict Michael's findings.

[carorees]

As I said, there MAY be benefits, but of course we just don't know! After 1 day there was a drop in insulin resistance which is around where the CER diet got to by the end of the week. And of course, this is just at the end of one week.

The problem with the IGF-1 results is that the IER diet on fast days involved a lot of milk which we know stimulates IGF-1 production (the diet provided 2060 to 2266 kJ [about 500 kcal] of energy and 50 g protein/day and comprised 1.136 litres (2 pints) of semi skimmed milk, 4 portions of vegetables (~80 g/portion), 1 portion of fruit, a salty low calorie drink and a multivitamin and mineral supplement.) Also if you look at their protein intake (table 3) it is a fair bit above what Dr M recommends.

I've met a couple of people who tried consecutive days and had a really terrible time of it, wouldn't recommend it.

Way I see it, the alternate day thing is to bounce your metabolism into burning fat instead of going into starvation mode - the alternating days are a big part of it I think.

Never tried consecutive myself, though I have recently had good success with proper fasting instead of the 600 calories on the fast days. Takes a while to build up your tolerance to fasting I found; I started just trying to get through the day without eating lunch which was tricky enough first couple of days. Then gradually went to 24hour fasts - 7pm to 7pm with 600 cals dinner. Then went to 36 hour fasts, which were actually easier to cope with for me. My problem is once I start eating I can't stop, so after dinner on a fast day was torture.

I have just found this site and therefore this is my first post. I have been on the diet since August and have gone from 13 stone 9 to 12 stone 10. I always thought the fast days had to be consecutive and have always fasted Monday and Tuesday. Having since read on this site that most people are doing non-consecutive days I am wondering whether I have been doing this diet correctly. I do find that the second fast day is easier than the first and assume it is because I have got used to not eating on the first day. It would be great to know the benefits/non benefits of doing two days together but it does seem as if no one really is sure.

[Moogie]

I think the risk of regular consecutive fast days is that your body may go into starvation mode and start storing what you do eat as fat. You certainly seem to be losing weight in any case! There have been no major studies yet AFAIK that look at which days or times are best, nor how best to split calories up (if at all) etc. If it's working for you and you're happy like that, it's all good I guess

Do you have a lot of weight to lose? I know you mention your weight, but we have no idea of your height/build/muscle so it's hard to tell. I had a few stone to lose and since August 31.5lbs have come off. I wonder if yours has not come off as quickly because of the consecutive days, or whether it's just that you don't have so much to lose?

Thanks for your reply, I am 5'10'' and average build. I am still slightly overweight. From what you have said it seems that you believe that separate fast days would more likely lose me more weight. I originally thought that two consecutive days would give other health benefits as well but maybe I was wrong?

[Moogie]

Really don't know one way or the other mate! It seems to be working for you in any case Can't hurt to try splitting the days if you want to, but I'm no expert, I'm only going on my own experience here!

Morning all

Has anyone done their fast days together?
For the past two weeks I have been doing 6:1, which I don't see as much of a problem as I don't have a lot of weight to lose, but I still want to reap the health benefits.
The thing is, I find fitting two separate fast days into my week is a bit of a bind. Mondays I don't work and I go for lunch with my Mum, Thursdays I work until 7:30pm & I am on my feet all day (on just 500 cals, seems a bit tough!), Friday it's film & pizza night at our house, Saturday is wine night and Sundays I do a roast - so the best days for me to do fasting would be Tuesday & Wednesday (on those days, I only work for 3 hours per day). Has anyone else tried doing two consecutive fast days? Is it too difficult? Or maybe I could alternate 5:2 (with consecutive days) and 6:1?
Of course, I could sacrifice pizza night, wine night or the roast but I don't want to miss out... Do I stop being soft and just give one of them a miss?!
What do you guys think??

Sophie x