My experience with Intermittent Fasting

Let’s start by talking about what is intermittent fasting. Wikipedia defines it as

“pattern of eating that alternates between periods of fasting (usually meaning consumption of water only) and non-fasting. A specific form of IF is alternate day fasting (ADF), which is a 48-hour routine typically composed of a 24-hour fast followed by a 24-hour non-fasting period. (ADF is also sometimes referred to as every other day (EOD) fasting or dietary restriction (DR).)”

It has been shown to have beneficial effects on health and longevity, similar to caloric restriction, but without the need for being in a caloric deficit. It’s also been shown to produce quite a number of physiological effects that are beneficial for body compositional changes (i.e. increase growth hormone, increased insulin sensitivity, increased fat burning, etc). All good things in my mind. However, my foundation in nutrition for body composition changes tells me that when you fast, you go into a catabolic state, and your muscles start wasting away to nothingness. Worse, your metabolism starts to slow, and you’ll gain fat just by staring at a lettuce.

Then I stumbled upon Brad Pilon’s Eat Stop Eat. It was very informative on why fasting is good, and doesn’t lead to loss of strength and muscle mass. It was also a good primer into how to fast. I then went on to scour the internet for more information on intermittent fasting. There are quite a few methods of intermittent fasting. Of the more popular ways are the 16-8 method (fast 16 hours, eat within 8 hours. See Leangains.com) and the Eat Stop Eat method (that is to fast one or two 24 hour periods per week.)

I’ve done something like this before in the past, where I only ate one huge meal a day. This was in the good old days of being a student, which was also the dark days of unplanned bodybuilding mayhem. I got lean… but also got small and meek. But then, those were the days when I ate about 2000kcals per day and ran 1-2 hours a day. In short, I was uneducated in the ways of getting strong.

Armed with the new evidence that this intermittent fasting works, and with 3 years of training and nutrition knowledge under my belt, I decided to give this fasting thing a go. I decided that the Eat Stop Eat method fit well with my working life, as well as my training regime. It’s been 10 or so weeks now since I started doing this. I basically fast one day a week at the moment, with maybe a second day on my off weeks from training. My fast day is usually Sunday. which is also an off day for me in terms of training (i.e. no training at all, maybe light Z-health drills). I start my fast after I have eaten my breakfast, and fast till the next morning’s breakfast at about the same time (give or take 1 hour).

Here is what I found so far:

1. I did not lose any muscle mass, although I did lose some weight in my first few weeks, but that was because I was in overall caloric deficit. In fact, my lats GREW during those weeks, thanks to my goal of hitting 20 pullups! I stopped the weight loss by adding more calories to the other days of the week (approximately 3500kcal on non training days, and 4000-4500kcal on training days).
2. I did not lose any strength, especially when I expected to lose some strength the most, which is the day AFTER the fast. Nope, I haven’t seen any loss of strength yet.
3. I did not feel hungry at all through the fast, as long as I ate my breakfast.
4. I have to eat breakfast. Otherwise I’m not a person you want to be with. ‘Nuff said
5. I quite like the feeling of not needing to cook and eat. Frees up a lot of my time. This is especially good when I am on-call, as I can do more work without needing to worry about cramming food into my mouth.
6. Two 24 hour fasting days in a week can be quite tough, but would be my first rapid fat loss option. I mean I can cut out about 350kcal per day just by adding another fast day.
7. I found that my carb tolerance has improved a bit. I feel fuller longer after my occasional oatmeal breakfasts, and after my post-workout carb meals. I also feel less sleepy after a carb meal.
8. I do not feel any of the symptoms of my metabolism slowing (i.e. drop of core temperature, cold intolerance, etc)

All-in-all, it’s been a great experience. I’ll keep fasting once a week, even in my current mass/strength gaining phase. I’m still getting stronger and bigger. At the same time I’m not putting on as much blubber as I did in the past. Is it for everyone? Is anything truly for everyone? It depends really. Try it and you might like it, or you might not. It might work for you, and it might not. Just like no one diet will work for everyone. Mind you, intermittent fasting IS NOT A DIET. It’s more of a lifestyle thing.

Does this mean that if anyone were to try intermittent fasting, they will lose weight and/or improve their health? Maybe. As the saying goes, “methods are plenty, principles are few”. Good nutrition principles still need to apply to get the overall benefit of this kind of lifestyle. For a good primer on good nutritional principles try the Precision Nutrition System. I’ll write about my nutritional philosophy some other time.

~ by jinsblog on 31st January, 2009.