When I first came across the term a few years back “Intermittent Fasting or IF” I was completely sceptical. Not because I am trained in the field of nutrition but because:
I like to eat.
Chewing and eating gives me great pleasure and IF just sounded wrong. But is there more to this IF thing?
What is it?
Intermittent fasting is an eating pattern where you cycle between periods of eating and fasting. It does not really give you very detailed instructions about what to eat, but rather when to eat. The nice thing about IF is that it has rules and is pretty black and white in terms of what you can and cannot do. I have always been a fan of eating and exercise plans like this because it is easy to implement and easy to follow. When something has simple rules you know if you are doing it right or doing it wrong. There is no grey area.
So for people that hate the idea of dieting, intermittent fasting offers a simple alternative that doesn’t involve calorie counting or starvation. In fact, IF is a lifestyle and timing shift rather than a diet change.
Three major mechanisms by which it is proposed that fasting is good for you:
- Increased insulin sensitivity and mitochondrial energy efficiency – Fasting increases insulin sensitivity along with mitochondrial energy efficiency, and thereby slows ageing and disease, which are typically associated with loss of insulin sensitivity and declined mitochondrial energy.
- Reduced oxidative stress – Fasting decreases the accumulation of oxidative radicals in the cell, and thereby prevents oxidative damage to cellular proteins, lipids, and nucleic acids associated with ageing and disease.
- Increased capacity to resist stress, disease and ageing – Fasting induces a cellular stress response (similar to that induced by exercise) in which cells up-regulate the expression of genes that increase the capacity to cope with stress and resist disease and ageing.
Currently the proposed benefits of IF:
|Limit inflammation||Improve circulating glucose and lipid levels||Reduce blood pressure|
|Improve metabolic efficiency and body composition||Cause significant reductions in body weight in obese individuals||Help prevent type 2 diabetes, as well as slow its progression|
|Reverse type 2 diabetes||Improve pancreatic function||Improve insulin levels and insulin sensitivity|
|Reproduce some of the cardiovascular benefits associated with physical exercise||Protect against cardiovascular disease||Modulate levels of dangerous visceral fat|
|Reduce LDL and total cholesterol levels||Protects against Cancers|
The “How to” of Intermittent Fasting
If you’re considering giving fasting a shot, there are a few different options for working it into your lifestyle. These are outlined below and are the most popular . However, there are multiple ways to implement IF.
Daily Intermittent Fasting (Leangains Method)
The Leangains model of intermittent fasting uses a 16–hour fast followed by an 8–hour eating period. This model of daily intermittent fasting was popularized by Martin Berkhan of Leangains.com, which is where the name originated.
It is pretty simple, you eat within an 8 hour window and then fast for 16 hours and then repeat. It doesn’t matter when you start your 8–hour eating period. You can start at 8am and stop at 4pm. Or you start at 2pm and stop at 10pm. Do whatever works for you. Most people find it easiest and most convenient to skip breakfast and eat between 12am and 8pm. For most people breakfast is often a rush or eaten alone so this is generally easiest to cut out.
Because daily intermittent fasting is done every day it becomes very easy to get into the habit of eating on this schedule.
Weekly Intermittent Fasting
Easy way to dip your toe into the water. Doing it once per week or once per month. The occasional fast has been shown to lead to many of the same benefits, so even if you don’t use it to cut down on calories consistently there are still many other health benefits.
In this example, lunch on Monday is your last meal of the day. You then fast until lunch on Tuesday. This schedule has the advantage of allowing you to eat everyday of the week while still reaping the benefits of fasting for 24 hours. It’s also less likely that you’ll lose weight because you are only cutting out two meals per week. So, if you’re looking to bulk up or keep weight on, then this is a great option.
Alternate Day Intermittent Fasting
Alternate day intermittent fasting incorporates longer fasting periods on alternating days throughout the week. For example, in the pic below you would eat dinner on Monday night and then not eat again until Tuesday evening. On Wednesday, however, you would eat all day and then start the 24–hour fasting cycle again after dinner on Wednesday evening. This allows you to get long fast periods on a consistent basis while also eating at least one meal every day of the week.
Remember these are only 3 methods that are the most popular and there are a number of ways to get into IF.
Other Great Resources:
- Brad Pilon wrote a good book on intermittent fasting called Eat Stop Eat, which you can buy here.
- John Berardi’s report on intermittent fasting is a great example of testing the ideas in practice. You can download it here.
- Blue Zones Diet & Research