Intermittent fasting for beginners
Intermittent fasting, simply stated, is cycling between periods of fasting and eating. It’s currently a very popular method to lose weight and improve health. Not only was it the “trendiest” weight loss search term in 2019, it was also prominently featured in a review article in The New England Journal of Medicine.
But there is nothing “new” about fasting. In fact, intermittent fasting might actually be an ancient secret of health. It is ancient because it has been practiced throughout all of human history.1 It’s a secret because this potentially powerful habit had until recently in many ways been virtually forgotten especially regarding our health.2
However, many people are now re-discovering this dietary intervention. Since 2010, the number of online searches for “intermittent fasting” has increased by about 10,000 percent, with most of the increase happening in the last few years.3
Intermittent fasting can provide significant health benefits if it is done right, including loss of excess weight, treatment of type 2 diabetes and many other things.4 Plus, it can save you time and money.
The goal of this beginner’s guide is to provide everything you need to know about intermittent fasting, in order to get started.
Intermittent fasting – isn’t that starvation?
No. Fasting differs from starvation in one crucial way: control. Starvation is the involuntary absence of food for a long time. This can lead to severe suffering or even death.5 It is neither deliberate nor controlled.
Fasting, on the other hand, is the voluntary withholding of food for spiritual, health, or other reasons. It’s done by someone who is not underweight and thus has enough stored body fat to live off. Intermittent fasting done right should not cause suffering, and certainly never death.6
Food is easily available, but you choose not to eat it. This can be for any period of time, from a few hours up to a few days or – with medical supervision – even a week or more. You may begin a fast at any time of your choosing, and you may end a fast at will, too. You can start or stop a fast for any reason or no reason at all.
Fasting has no standard duration, as it is merely the absence of eating.7 Anytime that you are not eating, you are intermittently fasting. For example, you may fast between dinner and breakfast the next day, a period of approximately 12-14 hours. In that sense, intermittent fasting should be considered a part of everyday life.8
It is perhaps the oldest and most powerful dietary intervention imaginable.
Consider the term “break fast”. This refers to the meal that breaks your fast – which is done daily. Rather than being some sort of cruel and unusual punishment, the English language implicitly acknowledges that fasting should be performed daily, even if only for a short duration.
Intermittent fasting is not something unusual and curious, but a part of everyday, normal life. It is perhaps the oldest and most powerful dietary intervention imaginable.9 Yet somehow we have missed its power and overlooked its therapeutic potential.
Learning how to fast properly gives us the option of using it or not.
Intermittent fasting for weight loss
At its very core, intermittent fasting simply allows the body to use its stored energy. For example, by burning off excess body fat.
It is important to realize that this is normal and humans have evolved to fast for shorter time periods – hours or days – without detrimental health consequences.
Body fat is merely food energy that has been stored away. If you don’t eat, your body will simply “eat” its own fat for energy.
Life is about balance. The good and the bad, the yin and the yang. The same applies to eating and fasting. Fasting, after all, is simply the flip side of eating. If you are not eating, you are fasting. Here’s how it works:
When we eat, more food energy is ingested than can immediately be used. Some of this energy must be stored away for later use. Insulin is the key hormone involved in the storage of food energy.
Insulin rises when we eat, helping to store the excess energy in two separate ways. Carbohydrates are broken down into individual glucose (sugar) units, which can be linked into long chains to form glycogen, which is then stored in the liver or muscle.
There is, however, very limited storage space for carbohydrates; and once that is reached, the liver starts to turn the excess glucose into fat. This process is called de-novo lipogenesis (meaning literally “making new fat”).
Some of this newly created fat is stored in the liver, but most of it is exported to other fat deposits in the body. While this is a more complicated process, there is almost no limit to the amount of fat that can be created.
So, two complementary food energy storage systems exist in our bodies. One is easily accessible but with limited storage space (glycogen), and the other is more difficult to access but has almost unlimited storage space (body fat).
The process goes in reverse when we do not eat (intermittent fasting). Insulin levels fall, signaling the body to start burning stored energy as no more is coming through food. Blood glucose falls, so the body must now pull glucose out of storage to burn for energy.
Glycogen is the most easily accessible energy source. It is broken down into glucose molecules to provide energy for the body’s other cells. This can provide enough energy to power much of the body’s needs for 24-36 hours. After that, the body will primarily be breaking down fat for energy.
So the body only really exists in two states – the fed (insulin high) state and the fasted (insulin low) state. Either we are storing food energy (increasing stores), or we are burning stored energy (decreasing stores). It’s one or the other. If eating and fasting are balanced, then there should be no net weight change.
If we start eating the minute we roll out of bed, and do not stop until we go to sleep, we spend almost all our time in the fed state. Over time, we may gain weight, because we have not allowed our body any time to burn stored food energy.
To restore balance or to lose weight, we may simply need to increase the amount of time spent burning food energy.
That’s intermittent fasting.
In essence, intermittent fasting allows the body to use its stored energy. After all, that’s what it is there for. The important thing to understand is that there is nothing wrong with that. That is how our bodies are designed. That’s what dogs, cats, lions and bears do. That’s what humans do.
If you are eating every third hour, as is often recommended, then your body will constantly use the incoming food energy. It may not need to burn much body fat, if any. You may just be storing fat.
Your body may be saving it for a time when there is nothing to eat.
If this happens, you lack balance. You lack intermittent fasting.