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Intermittent Fasting has experienced a surge in popularity in the past few years. However, just because there is a surge in popularity does not mean that this is a new concept. This article will provide you some contextual history to the idea of Intermittent Fasting as well as answer some of the top intermittent fasting questions.
What is Intermittent Fasting?
So, what is intermittent fasting? Is this a new fad or does it have any meaningful history?
Intermittent Fasting has its roots planted deep in our history. All the talk about ketogenic and paleo diets claim to be bringing dieters back to the way our ancestors ate when we were roaming the grasslands. While it may be true that we can “try” to recreate the diets we ate back then – we can’t really match those diets.
The foods that are available to us today are just too different. We aren’t eating bush meat (and eyes, bone, tendons, etc.) of wild animals. The fruits we eat today are sugar bombs in comparison to the relatively bland and small seasonal fruits available to our ancestors. Time, distance, and change of climate make the process of eating the same foods, in the same ways virtually impossible.
With that being said. If you are looking for a way to reconnect with your roots as a hunter-gatherer then Intermittent Fasting will get you there. Well, let’s start with what intermittent fasting is?
Introduction to Intermittent Fasting
Well, in its purest sense, intermittent fasting is periods of fasting (no eating) and periods of eating. It is as simple as that.
All people in the world already intermittently fast to some degree. Each night when you close your eyes you begin to enter into a fasting state (the start of this will be later for those that ate right before sleep as your body will still need to process that last meal).
When you awake you will continue to be in a fasted state until you consume your very first calories of the day (research out there suggests that the fasting state isn’t broken until you exceed approximately 60 calories).
Once you consume your first calories (or above 60 – approximately) then you have entered into the feeding state.
Everyone goes through his cycle each day. Periods of fasting followed by periods of feeding followed again by periods of fasting.
Intermittent fasting is simply a process where you become more aware and intentional about the timing of these periods.
The “Caveman” Diet
So, can we assume that our ancestors regularly fasted as part of their lifestyle? There is a lot of debate out there about whether our ancestors were intermittent fasters. What we can assume is that our ancestors did not have access to food to the extent that we had today.
It is reasonable to assume that our ancestors (even our modern day ancestors) experienced more food uncertainty than we experience today. So, did our ancestors cycle through periods of fasting and feeding? Of course, they did. How long were these periods? Well, that is harder to define because the records are simply incomplete.
While you will not be able to mirror the diet of our ancestors, either through paleo or ketogenic, you certainly can recreate periods of food scarcity by extending your fasting window.
Why Would I Want to Fast?
So now that you know what “intermittent fasting” is, why should you want to extend your fasting window? I mean, isn’t it basically starving yourself?
Humans have moved into a unique point in human history where the amount of food is a risk to our health, not because of scarcity, but rather because of excess availability.
Not only is the amount of food a problem but the nature of the food is also challenging to long-term health. The caloric density of our food has increased with easier and easier processing methods.
So, if we’ve reached a point in our evolution where the amount of calories we can consume is seemingly endless, then how do we quell the tide? This is where intermittent fasting can find a reasonable place in our lifestyle.
How Long Does it Take for Intermittent Fasting to Work?
People want results, right? Well, this is a tough question because there are two primary reasons why people use intermittent fasting. The first is for weight loss purposes. The second main reason is for a health reset and for the benefits of cellular cleansing.
Let’s start with the cellular cleansing question. Time in the fasted state will be the key to guide you through the stages of your health reset.
Up to 12 hours:
- When you have fasted for up to 12 hours you can expect that your body has moved into a phase of ketosis. In this stage, your body looks to itself for fuel and starts to break into your fat stores. The burning of these stored fats creates ketones. These ketones are then used for fuel. Now, this is a two-pronged benefit because you are burning fat (helps lose weight) and you are cleansing your body by burning stored fat. If you want to go “deep” technically check out this great article.
Hours 12 through 18:
- Moving from hours 12 through 18 your body starts burning even more ketones. At this window, you can start to see elevated levels of ketones in your body. This is why insulin sensitivity is so important. With insulin levels under check in your blood stream and your body sensitive to insulin release, your body is then able to access your fat stores during these fasted windows.
Hours 18 through 24:
- you begin to enter the coveted zone of autophagy. This is when your body sacrifices the weak cells and protects the strong. Survival of the fittest works inside your own body. So, weak or damaged cells are recycled by your body for fuel. Authophagy is the accelerator of cellular rejuvenation.
24 through 48 Hours:
- If you can hang in there and make it past one full day then the results really start adding up. Your body, rather that looking to continue to destroy itself, looks to double down on the strong. Remember, we have sacrificed the weak cells and are left with the strong. So, to protect and grow the strong cells your body begins to flood itself with human growth hormone. That’s right, the stuff that professional athletes and celebrities have been injecting for years to regain their youth. Well, you can create your own with nothing more than fasting.
Beyond 48 Hours:
- Insulin levels are extremely low. Your body has become highly insulin sensitive (which is a good thing). And your body will continue to burn fat for fuel and regrow cells in a stronger, more healthy fashion. It takes patience and practice to move into the periods of long-duration fasting. It is not for everyone. There are massive benefits to reap at fasts up to 24 hours or even 36 hours. But, if you want to push longer then there are accelerated benefits to be achieved.
So, that addresses the body reset question from above. You can start seeing meaningful results physiologically within as little as 12 hours of meaningful fasting. Every hour beyond that 12-hour point simply adds benefits.
The next question is – well if I fast when will I start seeing meaningful weight loss. Let’s do some simple math on this one to ensure that you understand what is “feasible.
Full 24-Hour Fasting Period – Weight Loss:
Let us assume that you fast fully for 24 hours. Only consuming water, black coffee, or black tea. All of which will pass through you (for all intents and purposes). So, no calories consumed. Therefore, your daily caloric intake was 0.
Now, the next question is how many calories a normal person burns through the simple process of daily life. We are not going to assume any exercise load that would add some level of burned calories. Let’s further assume that the resting metabolic caloric rate for women is 1,200 calories per day while the resting rate for men is 1,600. Calculating this is very difficult and quite complicated, but this gives us a baseline for discussions of this concept.
How many calories comprise an average pound of fat? Roughly 3,500 calories are in each pound of fat.
So, if you want to lose one pound of fat (3,500 calories) and you fast for a full 24 hours….drumroll…you will have lost nearly only 1/2 of that. Because, remember, your resting rate is about 1,600 calories.
I don’t want to bicker about what each person’s actual daily caloric load is because it varies based upon body mass, age, sex, activity level, etc. This example is here simply to demonstrate that it takes a long time to lose weight. It is a process. If you fast for 48 hours, you will still only be down about 1 pound.
The good news is that this works the other way as well. So, when you have a major cheat meal and you feel as though you’ve blown your entire program, just remember that it takes 3,500 calories to create a new pound of fat. So, no, that pizza, beer, and cake did not cause you to gain 10 pounds (most of the weight you gain from a night like this is water weight anyway). We are talking a game of ounces here – both ways – in terms of weight loss or weight gain.
Is Intermittent Fasting Healthy?
Many people are concerned that the process of depriving yourself of food is going to negatively impact your health. This isn’t an unreasonable concern to have. We have all been hungry. This feeling has led to fatigue, headaches, and general malaise. Isn’t this our body suffering and telling us to eat? For our own safety, shouldn’t we be eating regularly?
Shouldn’t I Eat More Frequently – Not Less?
In the past several years the only message we have heard about the frequency of eating is to increase it. Breakfast is the most important meal of the day. More, smaller meals throughout the day will help speed up your metabolism. The one key to most advice on food timing is more is better.
This kind of makes sense when you think of your metabolism in a simple way – like a burning fire. If you want to keep a fire burning what do you do? You keep it fueled with more wood. The more wood you provide, at more regular intervals, the more stable and intense the fire remains. This is the theory behind the “eat more” movement.
So, logic would hold that if you are fasting (and not snacking) that you will have no fire through your fasting window. You start a raging fire when you enter your feeding window. Your fire will die down again as you aren’t snacking between meals and therefore not putting any wood on the fire.
When you eat your next meal you have to start the fire all over again. So, isn’t it better to keep your fire burning all the time?
Well, metabolism really isn’t that straightforward. Eating frequently doesn’t increase your capacity to burn more food/calories. Rather, it simply means your body has to keep working from morning to evening trying to burn all that food. Also, for many people who eat late into the evening, this also means burning food while sleeping, which can cause sleep problems.
Just like you don’t want to leave your car engine running all day, you don’t want your body’s digestive system running non-stop. It is meant to cycle on and off, more like an air-conditioner rather than a fire.
Your digestive system should turn on, release insulin to assist, and then turn-off. Once it turns off it will no longer be releasing insulin into the system. Which, we have talked about before as one of the primary goals.
So, let’s stop trying to eat more and more frequently.
We hope you have enjoyed learning about some of the top intermittent fasting questions. If you have more questions please put them in the comments below and we will try to get them answered.
Thank you. Talk soon.