Unquestionably, the coolest diet hack to come across my radar in the past few years is a technique known as Intermittent Fasting (IF). IF has a small, but cult-like following that is growing in numbers at an impressive rate. If would probably be growing even faster if it wasn't so completely puzzling for most people that encounter it. To the uneducated, intermittent fasting probably doesn't look that dissimilar from simple starvation. However, if you can get past your initial aversions to it, IF is an astonishingly simple and effective strategy for dramatically improving both energy levels and cognitive performance...and burning body fat.
Curious? Good, you should be. I've been practicing a slightly-modified form of IF for about 18 months now, and I am a fanatical believer in this practice.
What Is Intermittent Fasting?
In practice, Intermittent Fasting is about as simple as it gets. A 24-hour day is broken up into 2 periods, the eating period and the "fasting" period. You do all of your eating in the (relatively short) eating period. The rest of the day, you eat nothing. That's it. Most people practicing IF do a 4-8 hour eating period, meaning that the other 16-20 hours of the day they don't put any calories in their body.
(I've modified traditional IF slightly to both increase energy and cognitive enhancement and make it easier to adhere to. I'll explain my modifications later in the article.)
Some Things To Know
There's no way around it, adopting IF is going to fundamentally change your relationship to food. Here's what you should know before diving in:
- It's Not For Everyone - If Intermittent Fasting "works" for you, consider yourself among the lucky ones. IF is a diet strategy that can radically improve the way you feel, think and look. Unfortunately, my experience is that there is a minority of people out there for whom the diet just doesn't "work". If you get a week-or-so into an IF diet and it's a struggle for you (i.e. low energy levels, hunger), listen to your body - IF is unfortunately not for you. More likely, IF will feel *awesome* in the first couple days and you'll be sold.
- Carbs vs. Fats - Your body has two primary pathways with which to convert food into energy. The first pathway is based on sugars and carbohydrates, the other is based on fats. While the two pathways technically can run simultaneously - the carbohydrate pathway will dominate by default. The key to IF's benefits comes from training your body to use primarily its fat-burning pathways.
- Change The Way You Think About Fat - This is the most understood subject in nutrition, bar-none. The widespread vilification of dietary fat (particularly saturated fats) is the product of misinformation based on outdated studies and some intentionally manipulated studies funded by grain-industry lobby. Eating fat (especially high-quality fats) does not cause our bodies to add fat. If anything, eating excessive carbohydrate (as most people do) is responsible for us adding undesired body fat. If this sounds completely foreign to you, I've explained the topic in more depth in a past Synchro Life Design article.
Why IF Works
Fundamentally, IF is a technique for training your metabolism to use fats as its primary energy source - and do so very efficiently.
First, let's look at "normal" eating. When we eat several times throughout a day, our metabolism goes through several cycles of breaking down carbohydrate and turning it into blood sugar, where it will either get used for energy or stored in cells for use later (i.e. as fat). After all the blood sugar is consumed or stored, blood sugar drops, taking energy and mental performance down with it. This triggers a "hunger-signal" and we'll eat again - and the cycle starts again. The constant up-and-down cycle of blood sugar throughout the day stresses our metabolism and results in lower overall energy levels and mental performance.
Because they only operate in the absence of carbohydrate, the fat-burning pathways of a "normal eater" get little use (generally only during sleep). These metabolic fat-burning pathways requires a complex set of enzymes to run properly, and the production of these enzymes gets de-prioritized by your body when fat-metabolism is under-used. With IF, however, your body doesn't have access to carbohydrate throughout the duration of the fasting period. For this reason, it will become effective at using fat as an energy source. Over the initial weeks and months of an IF regimen, your fat-burning pathways become more robust and your body simply gets better at burning fat.
Why IF Is Life-Changing
If your body gets better at using fat for energy, it will also get better at using stored fat for energy. This is why IF can be such a powerful tool for burning body fat and shifting body composition. Yes - looking hotter is great, but its really only part of why IF will dramatically improve your life.
The improvements in energy levels and cognitive performance are what most people (myself included) cite as the most dramatic positive impacts of intermittent fasting. These effects are explained by the fundamental differences in the way our bodies use fats and carbohydrates, respectively, as energy sources.
We've already covered how "normal" eating creates taxing cycles of blood sugar spikes and falls.
Contrast this with how your body uses fats for energy. Fats are digested slowly and must be sent to the liver for processing (into ketones) before they can be used for energy. This process happens steadily and consistently, with no dramatic rises or falls in ketones (i.e. energy) available in the bloodstream.
The shorter, more-dramatic cycles of available energy that define carbohydrate metabolism are, quite simply, harder on the brain and metabolism. IF trains your body to switch to a more stable fuel source (fats) - and improvements in energy levels and cognitive performance come as a result.
The brain, in particular, prefers a stable energy supply. Most people are unaware that the brain uses somewhere in the range of 1/4 to 1/3 of the body's energy during the course of a day. While the energy consumption of your muscles and other organs will vary widely depending on what your activity level, the brain's energy consumption stays relatively consistent. This helps explain why the switch to a more consistent and stable energy source produces such noticeable cognitive improvements.
My IF Modifications
Traditional IF is pretty rigid with strictly defined periods of eating and fasting. If your primary goal is to cut body fat, a traditional IF regimen with a very short eating period is about as effective of a technique as you'll find (some people do eating periods as short as an hour or two). When I've done this in the past, I've always noticed a slight dip in energy when nearing the end of my fasted period.
For me, energy levels and cognitive performance take priority over fat-burning, so I've modified traditional IF a bit to better fit my priorities. As I've covered, the key of IF is training your body to better use fats for energy. If you were to eat a significant amount of carbohydrate in the middle of your fasting period, your metabolism would switch over to using carbs and fat metabolism would be effectively shut off. What if you only ate fat during your fasted period? Because eating fats doesn't increase in blood sugar, fat-burning metabolism will keep running uninterrupted.
This is the essence of my IF modification - giving your body a few hundred calories of fat in the middle of your fasting period will keep energy levels and mental performance noticeably higher than if you were to do a strict fasting period. The trade-off is that because your body is using the fat you ate for energy, it will be less active in consuming stored fat from adipose (fatty) tissue. For me, this is well worth it.
Which brings me to the important point that all fats are not created equal, and some types of fats are far more effective for this "fat-snacking" purpose than others...
MCT's: An Intermittent Faster's Ally
Part of training your body to use fats more effectively is choosing the fats that are easiest for your body to convert into energy.
Fats can be broken down into three primary types: short-chain, medium-chain (MCT's) and long chain. The majority of fats in the world (vegetable oils, nuts, etc.) fall into the long-chain category. Long chain fats require a lot of processing before they can be used for energy. For this reason, they're not a great fuel source and not very effective for training the metabolism's fat-burning pathways.
Short- and medium-chain fats on the other hand, require far less processing by the body and are available as energy relatively quickly (as ketone bodies). Because they are so easily used for energy, your body will use them readily. Consuming significant amounts of short- and medium-chain fats will encourage your body to build up fat-burning metabolic pathways.
Short-chain fats are most commonly found in animal fats. Butter and ghee in particular are great sources of short-chain fatty acids (of course, use only organic, pasture-raised butter to avoid mycotoxin contamination).
Medium-chain fats (MCT's) are found in lower levels in a handful of vegetable oils, but far-and-away the best source for MCT's is coconut oil, which is about 2/3 MCT's by volume.
For the "fat-snack" modification described above, a few tablespoons of ghee, coconut oil, or coconut butter a few hours before the end of your fasting period will deliver excellent results.
My choice for this purpose is Cocotella, a ridiculously-delicious raw chocolate coconut butter. It does have a few grams of carbohydrate per serving, but most of those are fiber (which doesn't get broken down into blood sugar). The remaining carbohydrate is relatively so little it's not enough to start-up carb metabolism in any meaningful way. But best of all it's f'ing delicious. Cocotella has been my breakfast every day for about a year-and-a-half now, and I still look forward to it every morning.
What does a day in the life of an intermittent faster look like? Here's what most every day of my own life looks like:
9:00am - Wake Up
(9am - noon) - Drink 64-96oz of water lightly salted with Himalayan salt
12 Noon - Eat 4-5 Tbsp Cocotella
4:00pm - (fasted period ends) Drink 2-3 servings Synchro Genesis (over about 2hrs)
8:30-9pm - Eat Dinner (usually kale salad, sweet potato + 4-5 pastured eggs - somewhere around 2000 calories)
9:00pm - Fasted Period Begins again
This adds up to a 19-hour fasted period with a 5-hour eating period (plus the "fat snack" during the fasting period).
1) If you're going to do physical exercise, the very beginning of the eating period is the best time for this. Light-to-moderate exercise is generally ok during the fasting period (yoga, etc.), but you may notice lower energy during an intense work-out if it's done in your fasted period. This is because the body has trouble converting fat into energy fast enough to keep up with the energetic demands of more intense exercise.
2) To an extent, you can eat whatever you want during the eating period and you will still have success with IF. That being said, you can greatly improve the efficacy of IF by eating foods rich in high-quality fats during your eating period. This will make sure your body continues to run fat-burning metabolic pathways through more of your eating period. Eating less carbohydrate also allows your body to switch over to fat-burning metabolism earlier in your fasted period. For reference, I eat about 55% of my calories from high-quality fats during my eating period, with about 25% coming from carbs and 20% coming from protein.
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