Fasting - Still one of my favourite tools

One of the first blog posts that I wrote was about intermittent fasting which you can read here. I still believe this is one of the biggest game-changers when it comes to improving metabolic health and reducing visceral body fat (which is currently one of the biggest predictors of hospitalization for Covid).

Since that time I’ve also experimented with different types of fasting protocols including multiple-day fasts and something called the fasting-mimicking diet (FMD). While those previously mentioned methods would be considered more advanced they really should be reserved for people with fasting experience. For now, let’s focus on the beginner and intermediate methods.

When I think about the body and its response to fasting I try and imagine what life would have been like thousands of years ago when there were no refrigerators and no Costco. While our genetics have not changed in that amount of time, our lifestyle certainly has (and so have a lot of our conveniences). Our bodies are so intelligent that they have come up with a method of storing any additional and unused calories as body fat and then in times of need converting that body fat back into energy. This was a survival mechanism that we would have needed as food sources could have been scarce at times.

While a few people would argue against fasting insinuating it’s some type of “starvation” method, your body is naturally designed to be able to withstand periods without food. Studies have shown that for those that have a tendency towards insulin resistance (like me), their blood sugar and insulin sensitivity can be improved by incorporating some type of fasting protocol.

A common opinion is also that some people insist that you NEED carbohydrates to function properly. I can attest to the fact that my body actually feels more energized, my mind is more clear and I have better and stronger workouts in a completely FASTED state. How is that possible?

This is due to metabolic flexibility. Simply put, this means the body‘s ability to either use fat or carbohydrates as a fuel source. Not only has this helped me in my metabolic health, but it has also helped me in practical terms in my day to day. I fast when I have long shifts at work, when I am traveling or when I simply don’t have access to the type of food I want to consume. My body has learned how to switch from using food as a fuel source to using body fat as a fuel source! Amazing, right?

Well, where should we start? 

Method 1: 12 hour Time Restricted Eating (TRE)

A good place to start is to begin with creating some space between your meals and working on a 12-hour fasting window.  This is known as time-restricted eating (TRE) and simply means you have dinner and perhaps a snack but then nothing for 12 hours. The benefit is twofold: it will assist your sleep by not creating any work for your body right before you lay to rest and, also it gives your digestive system a break so that you can fully prepare for the next day.

This also is very much in line with our circadian rhythms where your body begins to wind down at night to prepare for rest so it is counterproductive to make it work via the digestive process.

Studies have also shown that it’s helpful for your brain and the “glymphatic” system to not eat anything 2 to 3 hours before you go to sleep. This system helps to remove waste materials from the brain while you sleep.

Method 2: The 16:8 intermittent fast

I wrote about this in detail which you can read here. Essentially this is where you fast for 16 hours and your eating window is shortened to 8 hours. Practically speaking this means your last meal or food intake is at 8 PM, you intentionally skip breakfast and the first thing you would eat is at noon the next day. Studies have shown when you incorporate this at least three days a week it improves insulin sensitivity as well as body composition.

Method 3: One meal a day (OMAD) aka 20:4 fasting

I’ve been following medical doctors who treat type two diabetes every day and one of their success tools is stretching the fasting window to 20 hours and eating for 4. This style of eating was written about by Ori Hofmekler in a book called the Warrior Diet. Personally, I will do this one to two days a week and I do it on my busiest days which I find works very well for me.  

Summary

At a minimum, I would recommend you stop eating 2 to 3 hours before you go to sleep followed by a 12-hour total break from eating. If you are looking to improve your body composition or your insulin sensitivity then start to increase this fasting window by one-hour increments.

For most people, when they hit the 16-hour fasting window their body has switched from using stored glycogen in the liver and is now typically relying on stored body fat as a fuel source. (To improve the speed of this switch over you can try some light walking or aerobic activity in the morning).

Caution: Until you become more metabolically flexible, I don’t recommend hard workouts till you know you can function well when fasting.  Follow this simple rule: if you don't feel well it's time to eat.  Feelings of hunger will obviously happen but watch out for light-headedness, dizziness, or headaches.  Those can also be signals of low blood sugar and it is likely time to eat something.

If you continue to feel energized with your fasting, I would recommend you stretch out the fasting window one hour at a time, a few days a week (on your busiest days). 

Tip: Remember to stay hydrated and do not consume anything with calories. I will drink a lot of water, black coffee, and herbal tea.

Remember what works for me may not work for you. I certainly feel that this is worth trying so let me know if you have any difficulty and remember to go slow and listen to your body for any signs and signals. 

Here’s to hitting your Health goals in 2022, 

Dr. Jason