Intermittent Fasting. IF. The world is going crazy for IF right now. Not only are the self-experimenters and thought leaders in the health and fitness world dabbling in it with increasing regularity, but even mainstream health and medical media is jumping on board. I get at least one new client a week asking me to put them through an intermittent fasting practice.
I don’t even like to call it “Intermittent Fasting,” because the “intermittent” part is implied. If it weren’t intermittent, that would be called “starvation.” But I digress.
There have been many benefits attributed to fasting, including:
It affects gene expression - it turns on our amazing human animal genes, reminding our bodies of a time when we were optimally and effortlessly healthy. We know that our ancestors had periods of food scarcity, and our genes are programmed with this in mind. If we can spark a memory of these healthier times within our epigenome, there is research to support that we can start to turn around diseases of the modern age.
It increases the level of Human Growth Hormone (HGH) in the blood.
It encourages cellular repair. When the body is not in Fight, Flight or Feed mode, it’s in Rest and Digest mode. Taking a long break from eating creates opportunities for these processes to occur.
It can help to mobilize even more storage fat off of the body; the caveat here is that your body has to have any idea how to burn stored fat - this is why fasting has to happen after fat adaptation. As a bonus: this type of fat loss seems to spare muscle wasting; one review study showed that intermittent fasting caused less muscle loss than continuous calorie restriction. (PubMed paper here.)
It lowers insulin levels, contributing to improved insulin sensitivity for people who tend toward insulin resistance.
It can reduce inflammation in the body by enhancing the body’s resilience and resistance to free radicals and oxidative stressors.
It’s been linked to reduction in some serious disease states, like Cancer, Alzheimers, and heart disease.
Fasting is also incredibly liberating. It is much, MUCH easier to follow than any other calorie restriction method.
Wait… did I just refer to fasting as a “calorie restriction method?”
I did. And it is. When you eat fewer meals, you just eat less food.
Once you’ve trained your body to enjoy prolonged meal intervals, it means that you have reached a point where your meals are extremely satiating for the long term. You just need to eat less food, less often. Your total calorie count goes down and you won’t have had to count a single one of them. You won’t have had to measure out portions of food - using a food scale or the “palm of your hand” or whatever. You won’t have to fuss over detailed macronutrient ratios. You’ll just eat when you want to eat and your body will take care of the rest. It’s kind of how the human body is meant to operate.
Read on for my quick synopsis on a few popular fasting methods:
Fast Diet (5:2)
Protein Sparing Modified Fast
eat.simple Organic Fasting
>> Leangains method - 16:8
This approach follows a 16 hour fasting window and an 8-hour feeding window, every day. Most often, people following this method skip breakfast and start eating around lunchtime. They eat throughout the afternoon and into the evening, fasting overnight. It’s a good place to start, as a 16-hour fasting window is not difficult for the average person to master. A fat adapted person, however, will find a 16-hour fasting window to be almost too short. Too easy!
16:8 gets a resounding “meh” from me, in terms of biohacking your body composition. I actually think this is how most people should eat. (This is how I eat on non-fasting days.)
>> ADF method - 24:24
The Alternate Day Fasting (ADF) method involves exactly what it sounds like: a 24-hour eating window alternating a 24-hour fast. 24 hours on, 24 hours off. Imagine finishing your lunch on Monday, and not eating again until lunch on Tuesday. Could you do it?
In my opinion, it's easer than it sounds, BUT you have to have fat adaptation dialled in to a precise science before you could regularly and effortlessly spend a full 24 hours fasted. A 24-hour fast is an interesting experiment; a biohack in the true sense of the word. You can really feel your body going through the process of this fasting method - you can observe ebbs and flows of hunger, you'll feel your energy change as the day goes on. I always find that my mental acuity grabs a gear on long fasting days. It's fun!
>> Fast Diet method - 5:2
This isn’t really fasting in the truest sense of the word, however it is one of the most popular methods. For my money, this is more of a traditional calorie restriction model, although it is one that seems more do-able than straight restriction right across the board. You only have to restrict two days a week.
For five days of the week, eat normally. These are your non-fasting days, and your best bet is to follow an eat.simple Fat Adapted eating style: emphasizing healthy fats and proteins; de-emphasizing carbohydrate; and minding the circadian rhythm of your food intake.
Two days per week, drastically slash food quantity to come in at about 500-600 calories. These two days are not meant to be back-to-back, either - not a Monday/Tuesday sort of scenario. Make sure to have a non-fasting day in between them.
On fasting days, eat two or three very small, light meals. Some people function best by beginning the day with a small breakfast, while others find it best to start eating as late as possible. Generally, there are two meal patterns that people use:
Three small meals: Usually breakfast, lunch and dinner.
Two slightly bigger meals: Only lunch and dinner.
Protein Sparing Modified Fast
Originally designed to kickstart rapid weight loss for very obese patients (who have a lot of stored fat to use an energy), leaner people have been experimenting with it - in some cases, supplementing with thermogenic fat-burners (ephedrine and caffeine stacks) too - to try to achieve a very lean body composition. In this way, this fasting method becomes very extreme.
PSMF is a high-protein, low fat, and low carb diet:
The limited carbohydrate intake forces the body to train itself to burn fat as fuel (fat adaptation).
The limited dietary fat means the body has no choice but to burn stored fat.
The high protein intake prevents the body from digesting body tissue for use as energy; this is the “protein-sparing” element.
It's also very low calorie, typically coming in at under 1000 calories for the day. This diet is meant to be a temporary measure, because it can get pretty real .
For obese patients and clients, there has been a lot of research to support this method for getting an early jump on weight loss. What’s more, although the weight loss is very quick, it seems to be well-sustained.
For people who are already lean, I simply can’t support this diet. It is highly restrictive and difficult. Plus, if you don’t have a lot of fat to burn on your body, then what…? You’re just starving yourself. All in all, it’s not simple, it’s not effortless, it runs the risk of being metabolically damaging, and it returns us to this dysfunctional relationship with food that I can't abide.
However. This is probably the closest thing a fat adapted person can get to a cutting diet. If you were going to enter into a fitness competition or were looking to shred out for a fitness photo shoot or a special event (wedding, beach vacation), this might be your ticket.
Just don’t ask me to coach you through it! *smile*
eat.simple method - Organic Fasting
Eat when you’re hungry.
Stop when you’re satiated.
Don’t eat again until you’re hungry.
Answer that hunger with a meal.
Ensure your meals have a substantial quantity of fat and protein so as to satiate you.
Be insulin sensitive (ask me how) so that the fuel from your food can be shuttled into your cells.
Be fat adapted (ask me how) so your body can mobilize stored fat into your cells for fuel.
With the eat.simple fasting method, you may find yourself venturing toward any of the different methods listed above, depending on the day, your appetite, your mood. You may find yourself hovering around a 16 hour fasting window for most regular days. Some days you’ll push that into the 20s, and your feeding window will shrink to 4 hours or fewer. Every once in a while you may go 24 or even 36 hours without eating, once you really get appetite control dialled in.
As you can see: my fasting method is basically methodless. And that is what makes it so darned liberating.
Intermittent fasting on a set schedule is not much different, psychologically, than eating on a set schedule (every three hours, six small meals, carb cycling, and other meal timing philosophies that I’m not into). I prefer fasting that happens organically as a result of an expertly-tuned appetite.
My #1 caveat for any fasting practice you choose to take on is this: do not force yourself to continue to fast when hunger has become too much to bear. If you have to white-knuckle through a hunger pang - please eat. To push through it, to call upon "willpower," is a one-way ticket to a broken hunger mechanism.
Always answer hunger with a meal. Losing touch with true hunger, satiety, and appetite is, for my money, a big part of what made us fat and sick in the first place.