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Intermittent Fasting -The BBC Horizon Documentary

BBC Journalist Michael Mosley – Gave a 5:2 version of Intermittent Fasting a try.

It was great to see the BBC picking up on Intermittent Fasting this week in an hour long episode of Horizon. As a popular show, it will have been watched by millions of people.

When I posted this on Facebook Lyle McDonald shot back with this:

“Predicting the future: folks in the UK will now adopt IF’ing. They will starve all day and binge eat at night and wonder why they are still fat.”

Unfortunately, I think he’s right. People will miss the wood for the trees. There is a very clear nutritional hierarchy of importance for losing fat:

1. Calorie Intake vs Expenditure > 2. Macronutrient Split > … 3. Timing

Simply skipping breakfast is not going to get you magically lean and shredded. Never lose sight of this and don’t let your friends fall into the trap. I’d like to talk about this and a couple of other points raised in the documentary.

Nutritional Hierarchy of Importance for Fat-Loss/ Muscle Gain

In broad simple terms:

  1. Calorie intake vs expenditure controls whether you gain or lose weight.
  2. The macronutrient composition of your diet (carbs/fats/protein) controls the ratio of how much fat vs muscle is lost/gained.
  3. Nutrient timing, for the non-athlete, is a very distant third. -All the research so far backs this up.

This means that you are much better off putting your efforts into getting the right quantity of food and macronutrients for the day before stressing over the timing of things; it means you don’t have to always sprint home from the gym to get a post workout meal in your “anabolic window”; and most importantly it means that you can’t just stuff your face with reckless abandon, thinking that the fat burning during the morning fast will take care of it.

Yes, fasting – which is a part of nutrient timing don’t forget – can help with stubborn fat loss, but only when the other two things are firmly in place.

5:2 Intermittent Fasting vs Alternate Day Fasting ADF

The journalist did a “5:2” version of IF, where he ate just one small lunch (~500kCal) on two days of the week and then just ate whatever he wanted for the rest. Blood lipids improved and he lost a lot of fat. -Fairly painless, very simple, and gives the benefits of fasting.

Michael also tried Alternate Day Fasting (ADF). The scientist that has been studying people doing ADF said she found that as long as people hit their macro targets for the “fast day” despite the instruction to “eat whatever they wanted” on the other days people wouldn’t over-eat enough to undo the previous day’s good work. -There was still an overall calorie deficit.

In looking at ADF vs 5:2 it’s quite easy to see why, that’s 7 vs 4 fast days in a two week period which is a significantly greater deficit. Would this make ADF better for the average person then? Probably not. Michael said he found it too restrictive whereas the 5:2 was manageable. The key to success with the 5:2 though is to eat “normally” on your regular days rather than binge.

The above two methods work through calorie restriction. -Number 1 in our hierarchy. While this isn’t going to give a gym trainee the very best results (try the Leangains principles), they are free, very simple and perhaps a good introductory step or way to help out an overweight friend that wants to diet.

The part about IGF-1 (Insulin-like growth factor 1)

The documentary goes pretty heavily into extolling the benefits of IF as a life extension tool / way to prevent diseases by keeping IGF-1 low. Let’s not pretend here, the first thing you thought when you heard this wasn’t about living a happy and cancer-free life till you’re 90 was it? You thought, “Oh shit, does that mean it will affect my muscle gains?” Fortunately the answer I believe is no.

To quote Alan Aragon here,

“While it is true that IGF-1 can have powerful effects within the muscle, we also have to keep in mind that it’s the muscle-specific variant of IGF-1 – now commonly known as Mechano Growth Factor (MGF) – that is relevant to muscle anabolism. The circulating form has very little effect on skeletal muscle.”

Or as Reddit user Arrozconplantano put it quite succinctly,

“There is no evidence systemic IGF-1 causes hypertrophy.  It’s not worth thinking about.”

If this really concerns you then feel free to go and pester Martin or Alan about it. They are far smarter then me and will be able to give you better answers.

Useful Links

******************************

We reached 1,000,000 blog hits today. -You guys made my mum cry. I hope you’re proud of yourselves.

I’ll have a guest post in the coming weeks by Beyond Brawn author Stuart McRobert.

Thanks for reading. -Andy.

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Please keep questions on topic, write clearly, concisely, and don't post diet calculations.

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Se não está quebrado...Dieta & Malhação

[…] duvido muito que isso aconteceria. Lembre-se da hierarquia de importância nutricional. A ingestão calórica diária e depois os macros (ingestão de macronutrientes específicos) são […]

Rodrigo Vaz
Rodrigo Vaz

Hey guys! Does anyone know a youtube link to watch the complete BBC documentary??? I searched for it but found nothing.

Andy Morgan
Andy Morgan

Did the link break? Oh well, wasn’t required watching anyway. Sure there is a torrent out there somewhere if you’re desperate to watch it.

Rodrigo Vaz
Rodrigo Vaz

I believe it did! Thanks for answering me back, andy.

Geo
Geo

The PBS.ORG website has it online this month.

Rodrigo Vaz
Rodrigo Vaz

Thanks geo, I’ve already downloaded it by torrent!

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Client Story: Rich – “Dieting Without The Drugs” | RippedBody.jp

[…] I came across leangains a few years ago but there wasn’t really much about it. When I watched horizon I couldn’t believe it and it was nice to hear back-up on what I believed made sense! Hence I […]

Christian cabrera
Christian cabrera

Where can i Find info about how to calculate My macros…..Please been looking all over and not finding à proper help
Christian

Mark
Mark

As luck would have it, there is an article on this very site with the title you’re looking for:

https://rippedbody.com/2011/10/23/how-to-calculate-leangains-macros/

🙂

Andy Morgan
Andy Morgan
trackback
If it ain’t broken… | RippedBody.jp

[…] doubtful it will. Recall the hierarchy of nutritional importance. Overall energy intake for the day and then your macros (specific macro-nutritional intake) are far […]

Ondrej
Ondrej

If one is skinny fat at around 15 percent bodyfat, rather weak and starting training, wouldn’t he be better of not to do any IF/macro counting and just eat normally with adequate protein and grow, then start to incorporate Leangains diet?

Mark
Mark

For what it’s worth, I don’t do IF because it’s some kind of voodoo magic for fat loss. I do it because:
1) increased energy level and mental clarity during the fasted state. The further into the fasted state I go, the more energy I have.

2) I get to eat like a man, not a boy. I don’t like eating 5 or 6 little kiddie meals. I like to eat a couple big meals a day. When you pack all your macros into just 2 (or 3) meals, you get more variety in what you can eat and still fit your macros.

And as others have stated, you can still go over your cals when IF’ing. If I’m going out to eat with friends, I’ll fast all day and just eat the one meal. But, with appetizers, entree, and dessert; I can easily blow past my daily cals in that one meal. 🙂

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Jonathan Evatt Online | The Virtues of Fasting

[…] Intermittent Fasting -The BBC Horizon Documentary […]

Scott Crawford, AIA, LEED AP
Scott Crawford, AIA, LEED AP

Reblogged this on .

Beau
Beau

Good analysis as always. Funny, I popped on the site to look for the answers to a question I’ve had about this very topic. Specifically, meal timing with regards to the fasting and training schedules.

I’ve been lucky enough work-wise to keep a 12pm-8pm eating window (2 meals), rising at 5am, training 11am-12pm. I’ve been getting shredded; the system works! Well, work has changed and now I often need to workout early morning. When I follow Martin’s advice and keep up the fast post-w/o and BCAA every 2hrs until my feed at 12pm, I feel TERRIBLY wiped out and starved all day, vs quite happily satiated when I feed big RIGHT AFTER my training session at 12pm.

How important is keeping the 16hr fast and scheduled eating windows? Is it heresy to train early morning, eat big, fast all day, eat big at 8pm, and go back to IFing and a 12pm-8pm feeding/fast schedule on rest days?

Andy Morgan
Andy Morgan

You could try that. Might feel hungry during the day but interested to see your response. Thanks for volunteering to test-pilot it.

Paul
Paul

I am interested in this as well

krishn
krishn

HI Andy, I am a vegetarian and I eat Rehydrated Soya Protein on off days, would you recommend it?

Andy Morgan
Andy Morgan

Recommend? No, I recommend huge steaks, roast beef, chicken breasts and bacon. I’m not a fan of resorting to supplements to get your protein so I don’t keep up with the different brands. Obviously as a vegetarian you have little choice when trying to get the recommended levels of protein here. Just be aware of BCAA content as not all protein is made equal for muscle protein synthesis.

Ondrej
Ondrej

Hi Andy,
if I want to combine 1x a week training with Leangains diet, should I still include 3 training days in terms of macros or it’s better to use Your guide and make it 6 rest+1 training day? I understand that the point of “training days” is to allow growth, but I suppose the diet is “prepared” for 3 training days which is reflected in all equations used. The third option would be a compromise: 2x a week training and 2 training days.

Andy Morgan
Andy Morgan

Just have slightly higher carbs on your training day and all the others the same.

Jeremy
Jeremy

i need reminders like this. Thanks Andy.

Andy Morgan
Andy Morgan

Regarding “nutritional hierarchy of importance”? You’re not alone bud.

Nick
Nick

Andy, congrats on reaching 1 million hits…10 million is right around the corner.

Andy Morgan
Andy Morgan

Cheers bud.

chris wray
chris wray

hello!i’m 26 year old male and train over an hour cardio or strength train 6 days a week. I’m really keen to try a 5:2 IF but i’m just concerned about my fasting day. can i still train and fast? sorry if i’m repeating a post!!

Andy Morgan
Andy Morgan

Yes, but I’d be more concerned about your 12 times a week training if you’re going for appearance goals and aren’t an athlete.

chris wray
chris wray

yes it’s appearance goals, wish i was an athlete!!!sorry i miss explained, i train either cardio for over and hour (cycling to work),or strength train for over an hour per day so 6 training sessions a week. i was going to strength train on my fasting days as i don’t fancy cyling 13 miles to work,12 hour shift then cycling 13 miles home without food…unless you think it would be ok?any thoughts please?thank you for your reply, you’ll be sick of replying to all million of us soon so i thought i’d sneak in for another post!!! 😀

Andy Morgan
Andy Morgan

Cycling in the morning fasted isn’t an issue. Eat lunch and you don’t need BCAAs for the journey home either. Don’t train 6 days a week with weights though.

chris wray
chris wray

Thank you for your advice i really appreciate it! 😀

Andy Morgan
Andy Morgan

Most welome.

James Wittering
James Wittering

Great piece Andy, just what I’ve been thinking about. I thought the show was motivating, if a little simplified. And yes, I did worry about the whole IGF-1 Vs physique thing. I’ve reached my target weight and BFR with Tim Ferris’s Slow Carb approach and find it easy to maintain with it. But I’m also interested in the benefits of IGF-1 lowering for health reasons.

So I’m thinking of mixing it up a bit: slow carb mon, wed, fri, fast tues, thurs and adding fruit and whole grains to the weekend (and a few beers). With some resistance training on the slow carb days.

I feel more confident now that the fast days won’t impact so much on the slow carb work out days now! Any thoughts?

Cheers again for covering this!

Andy Morgan
Andy Morgan

Thoughts:
The whole “slow-carb” thing works through calorie restriction via restriction of food choice, not the GI or II index. Thus if you’re at maintenance right now with 7 days of your slow-carb diet then adding two non-rescticted days without making adjustments to the others will lead to a weekly surplus and this gain.

jay
jay

Hi Andy. Usually i would work out on the Sunday but i can’t because of a family event out of town. There will be a Hugh meal of the best foods though. Do you think working hard on Saturday instead will still improve partitioning for Sundays meal if i kept calories and carbs lower on the Saturday?

I don’t want to limit food choices much as now, thanks to IF, i have a reputation to maintain regarding how much i eat.

Ondrej
Ondrej

Hi Andy,I am trying to find my own way. Do you think Eat Stop Eat 2x week 24h fast and 1x week High Intensity Training with dumbbells for 30 minutes can lead to similar results as presented here?

Andy Morgan
Andy Morgan

ESE and 5:2 are basically the same.

Ondrej
Ondrej

I meant if You think it’s possible to get the same physique as from Leangains/ Starting Strength or other here mentioned programme…using HIT once a week and IF(ESE) 2x24hours a week + sleep 9 hours. Theoretically, caloric restriction is caloric restriction and training is training. I am pretty sure it’ll take more time than 12 weeks but I believe I could get there. I am 22yo, former 179cm/80kg skinny fat, now rather skinny at 179/71 but muscle building is slow. My goal is cca 8 percent bodyfat and appearing really lean and musculular.

Andy Morgan
Andy Morgan

Yes of course, but the question is what’s more efficient.

Andy Morgan
Andy Morgan

Re. Partitioning: probably not. the best approach may simply be to skip the other meals except for the feast.

Darren
Darren

Andy, congratulations on the 1 million hits! And i am really looking forward to reading Stuart McRobert’s post!!

Darren

Andy Morgan
Andy Morgan

Cheers buddy!

Scott Tidmarsh
Scott Tidmarsh

As nice as it was to see IF being discussed in the mainstream on the BBC I thought the program was average at best.
Did you happen to catch the previous episode about HIIT? I thought that was far better.

Scott

Andy Morgan
Andy Morgan

In honesty Scott I think both programs were a disappointment. Points and science cherry-picked from research to make it more sensational and interesting for the main-stream masses, trying to make something complicated black and white. However sometimes oversimplification is a necessary evil to help motivate people to get off their arse and do something. -If it were too complicated then people would simply switch off.

I am however grateful that the BBC decided to do something on exercise, IF specifically. -It adds credibility to the idea of it.

Bart
Bart

As always you added little facts that matter.
Stuart McRobert ? WOW !!!

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