21 April 2013

IF: Intermittent Fasting

So, Intermittent Fasting (IF). The first time I heard of it, my response was something on a par with "Starving yourself?! Oh no, I'm not having any of that.", and so I can of course identify with those of you thinking the same right now. But, hopefully, both the premise behind it, and my reasons for embarking on it, will become clear(er). I shall provide arguments and evidence that I hope you will agree show that this works. And works very well.

Perhaps I should again explicitly make the point that I'm really not preoccupied with my weight/body, losing weight or food. OK, that's a lie; I am preoccupied with food... eating it, that is! I do feel like it couldn't hurt to just get rid of a few superfluous pounds but who doesn't think that? C'mon, be honest. Please rest assured, I don't think I'm fat and I don't think I should starve myself to achieve skinnydom.

Do you know what else it might be? I think I need something psychologically challenging in my life. My PhD is gone and I am slowly realising that I might be someone who always needs to be 'struggling with' or working towards something. It seems, if everything is just-so, then I'm always looking for something else. Maybe that's weird and self-sabotaging but hey ho. Anyway, I digress.

I now personally know four people who have employed IF, including both of my brothers and a long-time friend, all of whom wanted to shift excess weight/fat and shape their physique. They employed both IF and something called the Adonis Index. There is a female equivalent called the Venus Index; something else I've read a lot about. After sometime sticking to these respective programs, they entered a competition assessing progress. And I saw the level of the other competitors; it was not to be scoffed at! The result? They placed first, third and tenth. If you google IF and/or Adonis/Venus Index, you will find a plethora of before/after images.  I know what else you're thinking; oh yeah, that's great, they just look good. Wrong. For example, my brother does a lot of other physical exercise; rock-climbing, outdoor walking (even snow walking), cycling, running, etc. (read more on his blog). This isn't just for show and it is accessible to all; the message from their Optimum Gains project which spawned out of their experience.

I have deliberately withheld images of their results but I don't think I can stave you off any longer. Here you go:

Back to me. I'm not an ad agency.

Now, of course, that isn't quite the sort of physique I'm after. But there was definitely a lot to be said for the loss of body fat and a little bit of toning couldn't hurt, right? Apart from the plan to look into it all, I left it at being impressed and happy for them. Until, that is, I came home from work-and-jollies in San Francisco about a week ago to find my housemate reading a book about IF communicating the popular 5:2 incantation; Dr Michael Mosley and Mimi Spencer's The Fast Diet: The secret of intermittent fasting - lose weight, stay healthy, live longer. It is 2 days out of 7 fasting, leaving 5 days of feasting.

Reading the book itself and around the subject is left as an exercise to the reader. But I shall give you my take on it. There is a great deal of scientific research and description contained within about experiments performed to simulate IF both on rodents and people. After reading it, I was sold (enough) to try it. Now, what I haven't mentioned up to yet and is actually a BIG reason why I am trying it, are the other health benefits - not just linked to weight - that were so encouraging for me. For example,
  • reduced levels of Insulin-like Growth Factor 1 (IGF-1) leading to a longer life and reduced risk of cancer
  • increased activation of repair genes including a process called autophagy
  • entrance into the fat-burning regime producing ketone bodies to be used by the brain instead of glucose or glycogen
  • a fall in the fasting blood glucose (sugar) level and insulin, reducing the risk of developing diabetes and increasing fat depletion
  • increased insulin sensitivity i.e. more 'bang for your buck' with glucose storage and fat breakdown
  • reduced blood pressure and low-density lipoprotein (LDL) cholesterol (the bad cholesterol) thus reducing the risk of cardiovascular disease, having a heart attack or stroke
  • reduction in damage and chronic inflammation of the liver thus reducing the risk of a number of diseases; heart disease, cancer, stroke and Alzheimer's
  • increased production of a protein called brain-derived neurotrophic factor (BDNF) shown to stimulate stem cells to turn into new nerve cells in the hippocampus; the part of the brain essential for normal learning and memory, elevating mood and suppressing anxiety (an anti-depressant effect), and protection of the brain from dementia and cognitive decline, including memory loss and Alzheimer's and a delaying effect with this occurring much later in life e.g. 80 instead of 50 years of age
Now, that's not a bad list is it?

I will of course admit, the book cites research that shows positive results to support their program. I am sure there will of course be research which shows no results or perhaps even negative ones. But a) I fully accept that is all part and parcel of writing and selling a book; its message needs to sell, and b) there is yet to be a book detailing all the research performed in this area which stacks against IF. And since research publications are freely available to health professionals, if the research existed there would already be books to disprove its positive effects. On the contrary; the number of books being published on the subject continues to grow.

My point? I have made an informed decision.

If I feel strongly enough about something, what others think is, by and large, irrelevant. But, my biggest concern is that ill-informed people wish to give me their two penny worth. I grin and bear it whilst trying to retort with details, facts and information. But they seem to continue to hold on to the idea that I am on some fad diet because I heard about it through some terrible women's daytime TV programme or the plethora of people in the marketing department that are on it (their words, not mine!). As I've already said, I'd heard about intermittent fasting via my brother & co., who also made a measured, educated, informed decision about it (my brother is also doing a PhD in physics/biological physics). Plus, I can almost guarantee those people who are doing the 5:2 diet because everyone else is doing it (sheep! and a sheep is one thing I've never been.) probably won't have read around the subject and will just be following it like the ovie aries that they are.

This is all mildly insulting because I am both an intelligent individual and someone incredibly familiar with scientific research and its interpretation. But, I am also a very measured, considered person; I rarely embark on things lightly and without having weighed things up to a considerable degree. This, another result of being trained as an analytical person. I know intelligent people do make stupid decisions. In which case, if you deem it to be that, then let them carry, it really doesn't affect you. I would love to discuss it with you if you actually want to discuss it. If you want to tell me I have no idea what I'm doing or talking about then please, go and waste your words on someone else. Or better yet, read the book!

There are further intricacies with IF should you wish to delve further. For example, the ratio of fast to feed periods. Popularised by Martin Berkhan, 16/8 or 'lean gains' (LG) is an IF program with a fasting period of 16 hours, and a feeding window of 8 hours. During those 8 hours, participants may eat as few meals as they like, with the most frequent iteration being three meals. The 16/8 style is designed to work alongside training. Michael Mosley's book suggests 14/10 might work better for women. As can be found online, there are several other IF programs including alternate day fasting (ADF), two day fast, Eat Stop Eat and many more.


OK, enough with the background and motivation, let's get on with some specifics. An example of a 5:2 diet would be fasting on a Monday and Thursday; the schedule I am currently operating. It is favourable for me as it avoids the weekend (including Friday), has a reasonable gap between the days and gets one of the days out of a way at the start of the week. Also, it allows flexibility should something come up in the middle of the week and you wish to shift your fast day to accommodate.

I shall be trying to ensure I get a fast on either side of the feast, should anything 'come up' and I have to abort the fast. Specifically, for the 14/10 I would stop eating on a Sunday evening by 8pm and not eat again until 10am the next day (Monday). Between 10am and 8pm on Monday, I would consume just 500 calories. (So, whilst it's called a feast, it definitely isn't.) Then, I would stop eating from 8pm that day (Monday) and not eat again until 10am the next day (Tuesday). That gives two 14 hour fasts either side of a 10 hour feast window.

Now, before you freak out and say this is some unnatural, mentally-unstable eating plan, I draw your attention back to my previous post Me and food which talks about my eating habits as a teenager/youngster. I've already told you about my size and that I never used to eat breakfast during high-school and up to the age of 18. I would've described myself as definitely not a breakfast person. My meal the night before would be consumed by 8pm, the first thing I would eat the next day would be at 10:30am. So, just counting hours, I was following an IF style program even then for at least 5 days a week. There were probably two major differences; I wasn't eating such a wide variety of foods then as I do now and the calorie count was probably higher although I don't know by that much; I wasn't a big eater. Either way, it definitely was not something I was counting. And not something I am advising or advocating.

If doing this yourself, you would notice what works for you and what doesn't. I found I could actually manage 14/8 but struggled with 16 hour fasts, especially the second of the two, having to break it at 14 hours when I was getting a strong headache and visual migraine (going temporarily slightly blind in the process but that has happened even when I'm not fasting, before you panic). The 8 hours of feasting were fine and I found I could go longer if I didn't eat breakfast and consume my first meal at lunch ~12pm. So, the 10 hours might actually be too long a stretch for me and think I prefer the 8 hour feast period. The clocks show the timings for one fast/feast set I shall be going with.

That's a lot of numerical and biological information but hopefully you have followed the main thread. At this point, I'm very much just out of the blocks. I am already keeping a track of my weight and measurements. I wish I could monitor the other statistics e.g. but sadly they are out of my (monetary) reach. But I'm interested to see where this goes. Feel free to join me. ; )

What are your thoughts? Has anyone else tried The Fast Diet, the 5:2 diet or IF?


  1. Hey Jen,

    although we have both experimented with fasting in different forms (IF and Eat Stop Eat mainly) we have both found that it isn't conducive to our current goals, our own biological make up and our current level of conditioning.

    There is a good research base which shows the positive effects of IF but no studies (that we are aware of) have been conducted on it's long term health benefits; it is usually based on relative health markers (i.e. before and after).

    Basically our message is, have a look at the evidence, make a decision and give these things a go but don't get stuck in the mind set of 'this is the only way to go'. Fasting is not the only way loose a few pounds it just helps with getting there.

    As we say, it depends what you goals are. If you are trying to add mass then you want to optimise your calories (i.e. eat more - see our blog for a definition of more) and IF may make that a little more difficult. I'm currently trying to add mass and doing a IF style regime just wouldn't work, as eating enough in an 8 hour window becomes a bit of a chore.

    Don't just jump on something because it's popular, think about what that thing is telling you to do. As yourself: Is it good for you, will it help or hinder you, will it get you to your goals? Evaluate it, try it out, see how it goes and if it doesn't work don't be afraid to either stop it or change it. There are plenty of ways to reach your goal!

    Good luck Jen and I hope you have a positive experience with. Don't let it become your everything though - dieting and calorie counting can be very addictive and lead to high levels of stress and anxiety when you feel like you've stuck exactly to you calorie goals!

    Please feel free to ask any questions etc and we'll do our best to help out and answer them!

  2. Hi there,

    Thanks a lot for commenting. I'm completely in agreement with you and I never just follow things blindly. I made the exact point that I don't do something just because it's popular. I definitely understand there is more than one way to do things including losing weight; I have used other ways in the past. I'm just interested to see how this pans out. As I've already employed, I change it to suit my needs I don't just strictly count the calories and minutes. I'm very aware of the negative effects of this and it's not something I am concerned about at this point.

    That is true regarding long term health benefits and the lack of studies; that was my first thought after reading the book. I'd be interested to see the results of any studies on this in the future.

    I'm not looking to build mass right now. I probably have enough mass in my derrière for a small binary system to form.

    OK, sure I shall get in touch should I have any burning questions. It's good that you pointed out what your current stance on IF is as I wasn't fully aware. Still, your results using that were still impressive.

    Thanks again,