View Full Version : Basic IF question

Jason Naubur
02-22-2008, 10:46 AM
I have read some basics on IF, including this months article in PM magazine.

What I am unsure of - does your overall food intake stay the same?

ie: Say my plan was to start with a 15 hour fast, starting at 1800h - 0900h.

Do I:

a - just don't eat during that time and have my normal breakfast at 0900.
b - eat more at 1800 and then my normal breakfast at 0900.
c - eat normally at 1800 and eat more at 0900.
d - estimate my missed food during those hours and slowly make them up over the next feed cycle - however long that is.
e - any of the above will do.

It seems like a fundamental aspect that I am missing.


Mike ODonnell
02-22-2008, 12:16 PM
So you are doing a daily eating schedule between 9am - 6pm (have to convert for my non-military brain).

There are alot of options such as what is your goals for IF, what are your energy requirements for the day/activities, etc. There are several ways to IF, one can be the daily style, another can be every 3rd day. I would say for maximum health benefits and to make sure you are eating enough, to fast every 3rd day for at least 18hours. Plus to back it up some I would say get your food eating down first, aka eat paleo and get rid of the crap in your diet if any. From there it's something you play with and tweak to meet your performance needs, recovery needs and goals (fat loss, muscle gain, etc).

You could also do the warrior diet style which is more light eating during the day and a larger meal at night (personally I enjoy eating this way anyways as I find better energy and more mental clarity throughout the day). You could eat only meat/veggies throughout the day and then more carbs at night (although I would recommend them in the pwo window for optimal results)

As for fasting times, 15hours is minimal I believe to get any health benefits from fasting...and i am sure there are potentially much greater health benefits to longer fasting of 18-24 hours, but those can not be done daily by most people (18hours can...but you have to be able to take in a ton of food/protein in that small window if you are not wanting muscle loss) Overall, I come to think that for optimal fat loss and health you need a strong metabolism and longer fast periods, for that reason I think every 3rd day is a good start for most people. Daily IF while getting good results for alot of people, if done too long all the time (like 18hrs 7x a week) may lower the metabolism...which is not what you want in a weight loss phase. You can adjust however you see fit, 15hours can probably be done and keep the metabolism strong...but honestly eating from 9am-6pm only is not what I would really call fasting by the health benefits side(I tend to term it at longer periods of 18hours....but that is just me). At that point you probably see the better fat loss and health benefits of just eating Paleo all day long than 15hour fast and not eating 100% clean.

In the end...try something and see how it works. Learn how to adjust your macronutrients like getting enough protein for muscle building, healthy fats for energy, and enough carbs to keep your energy up while still getting fat loss.

I kind of went over some starting ideas on my blog below, and Allen made some good feedback observations in the comments on there as well. Take a look over there too. www.theiflife.com

Greg Battaglia
02-22-2008, 03:24 PM
Mike said most of what I was thinking. The object of IF is not to reduce caloric intake (at least in terms of the health benefits). So, for instance, if you're on a 1 on/1 off schedule and let's say your caloric needs fall at 2000 cals/day, you would be eating no food for 24 hours and then double the amount of food you would eat in one day over the next 24 hours feeding window. On the feed day you would consume 4000 calories in total. Optimally, you should attempt to spread your meals out evenly throughout the feeding window in order to prevent a huge insulin spike that could be caused by an enormous meal to break the fast. I agree with Mike when it comes to the 9-6 feeding window; it's really not IF in my book. A schedule that I have snugly gravitated towards goes like this:

Day 1- fast until 6:00 PM and eat until 10:00 PM, using my appetite as a guide (ie don't gorge yourself, but don't try to restrict calories either)
Day 2- Eat regular meals as desired throughout the day, never eating until stuffed, but until satisfaction


As Mike said, doing Fast-5 or Warrior Diet approach everyday can become too much and lead to a hypocaloric state, which eventually will register as a chronic stress rather than an acute. I find that following the Warrior Diet (with no snacking, no calories are consumed during the fasting period whatsoever. If you're eating any food at all, you're NOT fasting) every other day is optimal for my physiology because it allows me to compensate for the general lack of sufficient calories eaten during a 4 hour feeding window. During periods when I'm especially busy and must follow the warrior style everyday, after about 3 days I start to feel the fasting become more detrimental then helpful. My energy decreased, performance drops, and I become quite moody.

My recommendation is to tinker around with a few of the methods discussed here and listen to your body all along the way to see which method is your fit (assuming that you are already eating 100% Paleo and have already undergone fat-adaptation). If you find that you simply do not respond favorably to any IF method, you should scrap it and simply eat Paleo with no IF.

Hope this helped! Keep us posted

Robb Wolf
02-22-2008, 03:27 PM
Greg & MOD nailed it. give it a go and let us know how thigns are progressing.

Jason Naubur
02-25-2008, 08:48 AM
OK, I decided to 'jump right in'. My diet is good so I didn't have any reservations.

I finished dinner last night at 7:00pm, and have fasted until now (I will eat at 12 noon) making it 17 hours. Hunger wasn't that bad, surprisingly.

Couple of questions:

I had a black coffee - that does not break the fast in my understanding, right?
I skipped my 'greens+' morning drink and fish oil since that would break the fast, right?

I ended up packing up my breakfast and will eat it along with my lunch / snack today. Making breakfast for my wife and 3 kids sure made me want to eat though.

I'll try it every few days and see how it goes, and report back. Any advice is appreciated.

Next thing to try is dairy free...


Mike ODonnell
02-25-2008, 09:11 AM
Coffee is fine...black...skip the cream and sugar. You should take your fish oil at night anyways with food.

Try it every few days....see what happens. Slow and steady wins the race...that and you don't want to waste muscle.

Jason Naubur
02-25-2008, 09:28 AM
OK, I'll bite - what is the best way to track muscle wastage?

My thoughts:
- measure weight / BF levels and keep your LBM numbers up.
- work in low rep exercises and monitor performance.
- ???