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The mere mention of fasting used to conjure up visions of emaciated practitioners of exotic religions who had the discipline and training to accomplish a feat I would never be able to even attempt, let alone complete: to skip a meal or even not eat for an entire day or two! After all, conventional wisdom tells us we must eat every few hours, especially if you do any type of physical activity, to keep our blood sugar up lest we become woozy and pass out.
Not now, not me! I practice intermittent fasting (IF), popularized by the leangains web site, meaning I try to keep my eating inside an eight hour window everyday. What works best for me is attempting to eat all my calories between roughly noon and 8pm which ends up to be about a 16 hour, daily fast. There are some days that I “accidentally” fast for much longer as work or commitments get in the way–I simply forget to eat until much later in the day.
So why in the world would I choose to not eat, especially breakfast–haven’t we been told since we could remember that breakfast is the most important meal of the day? Oh, and breakfast has to eaten as soon as you get up in the morning or your day will be less than productive. That’s how I was raised and how I lived for nearly 50 years!
Once I became Primal/Paleo–by attempting to remove all grains, refined sugar, and processed food from my diet–I began reading about the possible health benefits of fasting and decided to give it a try. I believe there are numerous benefits for me–here are three big ones:
- Low blood sugar = less insulin which lowers inflammation
- A smaller feeding window = consuming less calories which keeps me lean
- Fasting promotes autophagy which helps with anti-aging and, hopefully, functional longevity
Controlling Blood Sugar
Based on the many books I’ve read on nutrition and understanding how my body works I’ve concluded high blood sugar is a very bad scenario which could potentially cause a plethora of serious health issues and diseases. My basic theory is when I eat food that excessively raises my blood sugar my pancreas produces insulin to lower the blood sugar. Excess insulin will cause chronic and systemic inflammation (not to mention, over time this insulin could damage my cells’ insulin receptors eventually leading to diabetes). I believe inflammation is a primary cause of almost all of our modern diseases and certainly accelerates aging. I’m obviously simplifying here, but I personally want to keep my blood sugar low and my insulin production minimal in order to prevent disease, slow the aging process, and promote longevity. IF has been proven to be a great method for me to keep my blood sugar low for very long periods of time. Let’s face it, if I’m not eating food for two-thirds of a 24-hour day, then the chances of me spiking my blood sugar during that fasted time are pretty slim.
For me, minimizing my blood sugar levels has some awesome benefits. I am no longer a slave to eating! Once I removed most of the refined sugar, grains, and processed food from my diet and began eating tons of vegetables, meat/fish, and quality fat, my body switched from primarily burning glucose (blood sugar) as fuel to burning fat. So at a high-level, once the fuel from my latest meal is burned off then my body’s own stored fat becomes the fuel source. That’s right, I have become a fat burning beast and can pretty much stay lean without effort.
Before converting to using fat as my primary fuel source and relying on glucose as fuel, I was a slave to eating. If I didn’t get carbohydrates into my system every couple of hours, especially on days with heavy physical activity, I would get the typical headaches, foggy brain, and dizziness associated with “low blood sugar.” I had to eat and if I didn’t my brain and body made me miserable!
Plus, I could never seem to shred those few extra belly pounds covering up those abs I knew were hiding under there. Want to know why? I would eat and spike my blood sugar, then my pancreas would pump insulin into my bloodstream to control the blood sugar and insulin essentially prevents the flow of fatty acids out of my fat stores making it impossible for me to burn fat. So once the glucose is consumed just a few hours later, my brain starts signaling for more fuel and it is time to eat again. Slavery.
Consuming Less Calories
Another benefit I derive from my practice of IF is I actually end up eating fewer calories verses when I eat all day. I think there are a couple of things going on here. Partially this is might have less to do with the IF and more to do with eating less carbohydrate and more quality fat and protein. Bad carbs, like processed grains and refined sugar make me hungry. For example, I can remember eating a huge plate of spaghetti with garlic bread at dinner time, say 6pm, and then be starving again by 8pm causing me to eat yet another huge plate! Compare that to a typical IF eating pattern where a meal of four eggs, bacon, and a large green smoothy at noon will often times keep me satisfied until 7pm and beyond (circumstances are different, obviously, like on workout days I’m probably going to eat more and maybe more frequently as I refill my tank).
In fact, I find myself really only eating two meals a day while fasting which leads into the second thing I believe causes me to eat less: compressing the eating window, combined with only eating two main meals daily, seems to make it harder for me to consume excess calories. I can only eat so much a one sitting and, as long I listen to my body and eat until I am satisfied (and not “Thanksgiving” stuffed), I am really finding it difficult to massively over eat. When I do observe a fairly high calorie day, I can usually go back and see a greater than desired amount of carbohydrate consumed.
So for the reasons above, IF coupled with a nutritious, low-carb, high-fat diet seem to act as a natural and painless governor on my calorie consumption resulting in a leaner body fat composition.
What is autophagy?
The word autophagy is derived from Greek words “auto” meaning self and “phagy” meaning eating. Autophagy is a normal physiological process in the body that deals with destruction of cells in the body. – Ananya Mandal, MD
This concept intruigues me as a 50 year old interested in figuring out how to thrive as I age. As the definition states, autophagy is a normal process that happens in each of us and, according to Primal guru Mark Sisson, it is also “the process by which cells recycle waste material, eliminate or downregulate wasteful processes, and repair themselves.” What does this fancy process have to do with IF? Well research shows fasting turns on autophagy. The benefits are fantastic, again from Mark Sisson’s post on IF:
Why is autophagy so important? It’s required to maintain muscle mass, and inhibiting it induces atrophy of adult skeletal muscle. It reduces the negative effects of aging and reduces the incidence and progression of aging-related diseases. In fact, researchers have determined that autophagy is the essential aspect of the anti-aging mechanism of fasting. Without the autophagy that fasting provides, you would get very few of the benefits. Fasting even increases neuronal autophagy, which aids in maintaining mental health and function. Short term fasting, too. No marathon thirty-six hour fast required.
So what’s not to like about IF? For me, I love it as the benefits listed above align perfectly with my health goals. Additionally, I enjoy the discipline required to execute IF. I feel great satisfaction in being able to adhere to my IE schedule when I can, along with knowing that being without food for an extended period of time not only won’t kill me but doesn’t adversely affect my physical or mental performance.
As I wrap this up, it occurred to me there are probably a couple of obvious questions so I’ll just go ahead and preemptively clarify…
“But aren’t you starving all morning and late at night?”
For the most part, no. It did take some getting used to and I became successful because I eased myself into it. I remember trying the eight-hour eating window once a week, then increasing to a few times a week and so on until the practice just became “normal” for me. Also, I would never be able to pull this off if I had not first become adapted to burning fat as my primary fuel source as opposed to glucose. Did I mention I’m a fat burning beast?
“Doesn’t working out fasted hurt your performance? Aren’t you worried about consuming your own muscles for fuel?”
Not in the least! Check out the expert on working out fasted, Martin Berhan, and let me know if you think IF is killing his athletic performance! His site has a link to a comprehensive study on “The Effects of Intermittent Fasting on Human and Animal Health” that is good reading if you are interested in details. That being said, everyone is different and your mileage may vary–I can only relate my own experience which does not show any athletic performance degradation due to IF. I do have friends way stronger than me and much more athletic that simply cannot workout in a fasted state. I do follow Martin’s recommendation to consume BCAAs before and during my workouts but the brand I use does not throw me out of my fasted state.
I would love to hear about your experiences with fasting and, as always…
Be smart in the kitchen and a beast in the gym!