As humans, we’ve always heard, 'You have to eat. You have to eat.' The average person thinks that in order to stay alive, the body needs to have food not only every day, but every few hours. But in fact, that's not true. If you think about it, throughout history, there have been lots of times where people didn't eat. Times of economic struggle like the great depression, or times of natural disasters like droughts or floods, have forced large segments of the human race to go for days (or longer) without food. There are dozens of stories where people have been stranded at sea for weeks with no food and survived.

That's really what body fat is for. It's simply just stored fuel; stored food energy. When you go without eating, your body uses this stored fat as fuel.

Since my fast last year (which you can read about here), I’ve done even more research on the subject. One of the places my research led me was to Dr. Fung. He has implemented fasting in his practice, with unbelievable results. He has been able to take many patients off all medications; they're losing weight, reporting increased energy, and their type two diabetes has been reversed.

While fasting, I don’t make a big deal about it. Outside of my immediate family, I didn’t tell anyone that I was going on a water fast. It came up once or twice as I had some lunch appointments for work and people get curious when you don’t order any food. This led to some interesting discussions and people sharing some things they thought were facts about fasting.

One common myth is that fasting will lead to loss of muscle mass. This doesn’t happen. Your body actually downregulates protein catabolism and upregulates growth hormones in response to fasting.

When fasting, you switch over from burning sugar to burning fat. Once you start burning fat, there's almost an unlimited amount of calories there. You could go for days and days. At the bottom of this post, I have some charts (you know I love charts) that graph the changes my body went through during the fast. One big one was my ketone levels. As you can see in the graph, it only took me three days to get into ketosis, where my body was burning all fat for fuel.

Another common fear is that fasting equals starvation, which is not true. First of all, starvation is a forced situation that you have no control over whereas fasting is optional. I had complete control. I always had access to food, so breaking the fast was always an option. Many also believe they cannot or should not fast because it will send their body into "starvation mode" — a situation where the body starts holding on to fat rather than burning it off.

What actually happens during fasting is that after 3-4 days of fasting, your metabolic rate is actually 10% higher than when you started. The body has not shut down at all. In fact, what it has done is just switched fuel sources. It switched from burning food that you are constantly supplying it with to burning your existing body fat, which even the skinniest people have plenty of.

This is also why fasting tends to increase energy instead leaving you feeling drained, which is what most people think would happen. If you're overweight and lethargic, fasting helps unlock all that energy already stored in your body that you previously had no access to. Fasting forces your body to start accessing those stores of energy, and once that happens, your body suddenly has a near unlimited supply of energy. As I got into day four and beyond, I had tons of energy and felt alert and focused all day.

Other benefits of fasting include:

· Increases insulin sensitivity as there is less fluctuation in blood sugar levels.

· Improves body repair, recovery and healing from decreased inflammation.

· Lowers stress levels, decreases blood pressure and rejuvenates the body.

· Increases immunity due to better cell resistance.

· Enables reduction in cancer cell proliferation.

· Slows down aging and cognitive decline

· Lowers the risk of heart disease.

· Solves digestive problems such as gastritis, irritable bowels, constipation, diarrhea, gas, dyspepsia, and loss of appetite.

· Promotes human growth hormone production, which helps your body burn fat, build muscle, and slow the aging process.

· Regulates ghrelin levels, also known as “the hunger hormone.”

· Decreses triglyceride levels.

While the majority of the population would likely benefit from water fasting, you should always consult with a trusted medical professional prior to fasting. There are also several groups of people that should not consider a water fast. If any of the following apply to you, you should NOT do extended types of fasting:

· Underweight, defined as having a body mass index (BMI) of 18.5 or less.

· Malnourished (in which case you need to eat healthier, more nutritious food).

· Children should not fast for longer than 24 hours, as they need nutrients for continued growth. If your child needs to lose weight, a far safer and more appropriate approach is to cut out sugars and grains. Fasting is risky for children as it cuts out ALL nutrients, including those they need a steady supply of.

· Pregnant and/or breastfeeding women. The mother needs a steady supply of nutrients in order to assure the baby's healthy growth and development, so fasting during pregnancy or while breastfeeding is simply too risky for the child.

· If you're on medication, you need to use caution when fasting, as some may need to be taken with food.

So what exactly did I do?

I started on a Saturday morning and for a full 5 days, I only drank water. No solid food or other liquids that contained nutrition/calories (like fruit juices, almond milk, etc.). If I was cold, I would drink warm water, but most of the time it was just room temperature straight out of the faucet. During this time, I abstained from all forms of exercise as well.

I was hungry the first day, but then the feeling subsided. After about 3 days, the digestive fire began to slow down and become weak and I no longer thought about food at all.

I noticed that despite brushing my teeth, my breath had a bit of an odor on days 2-3. A little research revealed that during a fast, toxins may get removed through the lungs, which explains the foul breath.

On day three, I felt a little weak in the morning and had some acid reflux as my stomach adjusted to being empty.

On day five, I was cold all day. I had a similar experience last year. It doesn’t help that I do this in January when it’s freaking cold outside!

Breaking the fast is as important as the fast itself. When the body goes without food for this long, the digestive system becomes weak. So you simply cannot eat or digest large quantities of food. It will be a shock to the system. So I had to gradually increase the digestive fire and bring it back to normal.

The first step was to start drinking other liquids. On day six, I continued drinking water, but added in a little bit of coconut water, which has a few calories.

On day seven, I had bone broth and a few light soups.

On day eight, I introduced the first solid foods. I had some steamed vegetables and banana as they are easy to digest. I could immediately feel my stomach cramping as it tried to get the digestive juices flowing again, but the cramping only lasted a few minutes.

On day nine and after I was able to get back to my normal diet. I was still very careful not to overeat and overload the stomach. I made a point to chew my food longer than normal and to eat smaller amounts a number of times, rather than eating too much once or twice.

Some things that I did this time around that I didn’t last time were to take Digestive Enzymes every day. Taken while fasting, digestive enzymes pass through the stomach and travel throughout the entire digestive tract, where they dissolve hardened mucus impacted into the bowel walls, digest partially digested food residues, destroy microbes, and help eliminate other toxic wastes; enzymes are especially effective in digesting and eliminating putrefactive proteins and fermented starches impacted within the walls of the digestive tract.

I also spent about 5 minutes a day oil pulling. I'd simply put a spoon full of coconut oil in my mouth, swish it around while I was fixing the kids school lunches and then spit it out. Oil pulling works by cleaning (detoxifying) the oral cavity in a similar way that soap cleans dirty dishes. It literally sucks the dirt (toxins) out of your mouth and creates a clean environment in your mouth!

I also pricked my finger each morning and monitored my blood glucose and ketone levels. This provided some good information as I was able to see how my body was reacting, which didn’t necessarily coincide with how I felt.

During the first 24 hours after beginning fasting, Insulin levels start to fall. The breakdown of glycogen releases glucose for energy. Glycogen stores last for roughly 24 hours.

Into day 2, the liver manufactures new glucose from amino acids in a process called “gluconeogenesis”. Literally, this is translated as “making new glucose”. In non-diabetic persons, glucose levels fall but stay within the normal range.

Heading into day 3, the low levels of insulin reached during fasting stimulate lipolysis, the breakdown of fat for energy. The storage form of fat, known as triglycerides, is broken into the glycerol backbone and three fatty acid chains. Glycerol is used for gluconeogenesis. Fatty acids may be used for directly for energy by many tissues in the body, but not the brain. Ketone bodies, capable of crossing the blood-brain barrier, are produced from fatty acids for use by the brain. After four days of fasting, approximately 75% of the energy used by the brain is provided by ketones. The two major types of ketones produced are beta hydroxybutyrate and acetoacetate, which can increase over 70 fold during fasting.

After 4 days, high levels of growth hormone maintain muscle mass and lean tissues. The energy for maintenance of basal metabolism is almost entirely met by the use of free fatty acids and ketones.

Overall, this was another successful water fast. It's a good challenge for me and I like doing it at the beginning of my training season to get my body ready for several months of hard workouts. ​I'll continue to look into alternative fasting methods and other things that I can monitor in the future (such as blood pressure and body temperature).