It’s definitely summer here. With the cyclone passed, we now experience high temperatures, between 28 degrees at night and up to 35 during the day. Sitting outside on my veranda for my morning coffee shortly after five o’clock is beautiful. All is still quiet and calm. Before the sunrise a few minutes after six, it’s cool and breezy. My house tends to collect the heat during the day, and will not shed it all during the night, as you’d expect if the temperature only goes down to 28 degrees or so. So at times I use the aircon for an hour in the evening to cool it off a bit. For the night, I turn it off, as I don’t sleep well with closed windows.
In short, it’s February, on a tropical island in the southern hemisphere. :)
By the end of January, I decided to fast. I have fasted many times before. Not for religious reasons. I am not religious, and think that religion has done, and is doing, more harm than good. But that’s a topic for another day.
I usually start with a modest goal of fasting for one week, with the intention to check how I feel by then and decide if I want to continue. As the body and metabolism undergoes quite a change, fasting shorter than a week does not make sense, it needs sufficient time to adjust to a new homeostasis. For clarity, by fasting I mean to eat nothing, just to drink enough, water and highly diluted fruit juice, plus some bouillon from time to time for its additional nutrients.
I ended up fasting for four weeks. Once my metabolism had switched to feed on my long-time reserves, aka fat, I felt fine. Not eating anything keeps your insulin levels low, which activates burning of fat, after your liver’s glucose reserves are used up (after two to three days). That switch-over period is the most difficult to go through. But once you have experienced the switch before, you know what’s going on and can pull through without lots of troubles. But it’s important not to eat anything, as else the insulin level goes up, and fat-burning is inhibited, and you lack energy.
The liver will also manufacture glucose using gluconeogenesis, using the glycerol that’s a byproduct of the breakdown of fat. So, no, there’s no danger of low blood sugar levels. In addition, the brain can also use ketone bodies as nutrient, which are produced as a byproduct of metabolising fat as well. Hence, no risk of turning into a blabbering idiot while fasting.
In summary, fasting simply triggers the basic survival metabolism of our ancient ancestors for times of low food supply.
Fasting is also in interesting experience as regards the reaction of the people around you, if you tell them, which I tend not to do. Many simply cannot understand that it’s possible to function normally without food. “I would feel dizzy and not have the needed energy!” However, they never even tried. Eating is such an inherent part of our daily lives. And there are so many myths about fasting. “Your body will burn your muscles!” No, this will not happen, as long as the body fat is above about 4%. To compare, a well-trained marathon runner carries about 8% body fat. Why would evolution result in a physiology that inhibits humans (or any other animal for that matter) to escape or fight a danger, by burning muscles in lieu of fat, in times of low food supply or starvation?! In fact, during fasting, growth hormone secretion is increased to preserve muscle and bone tissue mass.
I didn’t change my daily life by one iota during the fast – I could “function” as usual: diving, daily fitness regime, everything. Actually, I felt really good and energetic. It’s as if the body “knows” not to rely on any external food, and gets into a well-balanced homeostasis purely based on the internal reserves. OK, there’s one thing I couldn’t do, I admit: to have lunch with a friend, as we usually do once or twice a week. She was happy to hear that I had ceased fasting, “finally”! :)
This well-balanced feeling of my body and mind felt great. I was even somewhat reluctant to start to eat again.
My body mass index went from 24.3 down to 21.6. I haven’t been as lean for decades. With age, over the years, the “reserves” tend to accumulate. And my mirror tells me that I still have some to get rid off. Which I intend to do, not by full-time fasting, but a technique called intermittent fasting. As we know that high insulin levels and the ensuing insulin resistance are the main cause for obesity, the goal of intermittent fasting is to allow the insulin levels to drop sufficiently over a time period as long as possible during each day.
We have already a fasting time each day: during our sleep. “Breakfast” signifies that – breaking the nightly fast. So now I experiment with extending that nightly fasting time, either by adding to it in the evening or in the morning.
Now that my insulin levels have dropped and my insulin resistance has diminished during my four week’s fast, I am simply cautious when to eat in order to keep the “daily fast” period as long as possible. When I eat, I eat whatever I want. The timing is crucial, not the meal (within limits, of course; a discussion of healthy, low insulin level triggering food is out of the scope of this already lengthy post!). As a result, I have lost some more weight since I started eating again, if only slightly. Then again, it has only been a bit more than a week. Further experimentation needed, but the goal is to settle on a long-term regime that allows me to at least hold my weight, while I eat all my beloved food. I love good food.