For several years now, I’ve played with different dietary protocols that revolve around the idea of intermittent fasting. Simply put, IF is a period of eating followed by a longer period of not eating. This is the opposite of what a large portion of the Western world does, eating pretty much from waking up until going to bed. There is a growing body of evidence to support this as a valid dietary strategy for many people, demonstrating positive effects on insulin, leptin, and ghrelin (among other metabolic hormones) and should not be confused with either anorexia or bulimia.
My original interest was piqued by Ori Hofmekler in his book The Warrior Diet. Of all the information I’ve read, this is definitely the least scientific. However, containing a large number of citations, that isn’t to say there’s no solid science behind it, it’s more the anthropological stuff that seemed a little over the top. The basic idea is that we should live like ancients used to. They would work during the day, either hunting or gathering. While working, they might eat a little but not very much. The primary meal would be consumed at the end of the day after all the work was done, over three to four hours.
The short version is that the day is divided into the ~20 hour “undereating phase” and a ~4 hour “overeating phase”. During the former, you’re allowed very small amounts of fibrous vegetables, fruits, and small amounts of protein. During the latter, the idea is to begin by consuming raw fruits and vegetables first, then wait 20 minutes. Consume cooked vegetables, then meat, then wait another 20 minutes. After this, drink a glass of water or tea and see if you’re still hungry. If you are, then eat some more and repeat. The purpose of the 20 minute wait is to give your brain enough time to receive and process cholecystokinin (CCK) signals, which is one of the mechanisms to tell us when we’re full. If you’ve ever eaten at a fancy French restaurant with courses, you tend to eat less but feel satisfied because of the break between courses that allow those signals to catch up. Cool, isn’t it?
This led me into trying to find out more about the idea of IF and, from there, I discovered Arthur De Vany’s book The New Evolution Diet. De Vany is credited as the grandfather of the modern paleo movement. The concept of paleo, also sometimes called “primal”, has been tackled many times by many authors and is very popular. In the context of this book, IF was presented as more randomized, skipping meals sometimes and then going longer periods without eating. I never actually practiced this version for various reasons, but it did have a lot of great information on some of the science of fasting.
From there, I discovered Leangains by Martin Berkhan. This is the most rigid and comprehensive of all the protocols and the only one that doesn’t rely at all on intuition. Leangains is built around carb and calorie cycling. It’s most effective when combined with a 3 or four day weight lifting schedule, ideally occurring within the feed window. The baseline is to start with a 16 hour fasting window and an 8 hour feed, some people adjust to their own tastes. High protein is consumed every day. On training days, intake is low fat and high carb, with most of the overall intake happening shortly after training. On rest days, intake is moderate fat and low carb. Specific targets for macronutrient requirements (protein, carbohydrate, and fat) are set depending whether you’re training or resting. This has an advantage as the goal isn’t to count calories but macros, making it slightly easier to keep track of how much you’re eating. RippedBody.jp has a number of suggested ways to implement the Leangains ideas, depending how specific and obsessive you choose to be, with some guidelines for making it more intuitive. Success at this requires discipline as well as forethought; to get most of the benefits, it’s incredibly important to plan ahead.
The last protocol to discuss is Eat Stop Eat by Brad Pilon. Like Leangains, this one works on a defined schedule of eating and fasting, but isn’t quite as rigid as Leangains. In fact, this one isn’t a diet at all, since it doesn’t really cover what you eat, at least not in any detail. The simple version of this is two weekly 24-hour fasts. The fasts are non-consecutive and can be whatever days you choose, even different days per week if you’d like. For example, if you finish dinner at 6pm on Monday, you would not eat until 6pm on Tuesday, then eat as you normally would. Black coffee, water, unsweetened tea, and sugar free gum are the usual tricks people use to make it through the fasting period. It’s generally agreed that the most effective one is to do something to take your mind off not eating.
There’s a plethora of information out there about intermittent fasting. It isn’t necessarily for everyone. Some people won’t ever be comfortable and some people will love it immediately.
My experience with IF has been mostly positive. Discipline breaks and occasional poor planning on my part have kept me from getting exactly what I want but I also know that’s more me than the protocols. Overall, I find IF to be convenient, since I don’t have to spend as much time preparing food and I never really liked eating in the mornings anyway. I also really like the flexibility, as I’m now used to managing hunger. Where a lot of people complain about being hungry if it’s been more than two hours, it doesn’t bother me at all.
My main approach at present is Leangains (though, again, discipline breaks…). However, I’ve decided that I want to start trying to incorporate 24-hour fasts into my schedule as well. My first intentional day-long fast is currently in progress. I just passed hour 20 and it really isn’t that bad. I’m looking forward to seeing what happens as I do more of this.
These aren’t “diets” in the sense that most people use that word. Most people use that word incorrectly, as it happens. These are lifestyle changes in a very real sense. If you’re looking to try something new, intermittent fasting might just be what you’ve been looking for.
