'The best of all medicines is resting and fasting' – Benjamin Franklin
Fasting is abstaining from food for a given time by choice. Fasting is nothing new by any means. Many regularly practice fasting for religious reasons, and our ancestors were of course forced to fast without 3 square meals a day. Contrary to what you might expect, many people feel increased energy and mental clarity during or after a fast. Fasting practices are gaining popularity for their health, weight loss, and anti-aging benefits.
What is fasting?
If the idea of not eating for 24 hours or more freaks you out, then Intermittent fasting (IF) might be more appealing. IF is a more user friendly way to fast because it means you still eat every day. IF is commonly done by fasting anywhere from 12 to 16 hours of your day, to eat in a smaller window of time. It’s easily achieved if you don’t eat after dinner, and wait at least 12 hours before eating breakfast.
Given that eating is one of the most inflammatory things we do to our body every single day, giving the digestive system a break can be a powerful healer for those who have gut issues, blood sugar issues or serious health challenges. When we feel sick, we often naturally lose our appetite, our bodies way of decreasing inflammation, and using energy for repair processes.
Many of us struggle with blood sugar issues, and a lack of ‘insulin sensitivity’, meaning we struggle to get energy from our food efficiently. Insulin is the fat storing hormone, and as we lose sensitivity to insulin, the cells become insulin resistant, and struggle to accept glucose (energy) in from the blood. If we are caught on the perpetual blood sugar roller coaster, our body experiences accelerated aging, stress, and is primed for cravings and fat storage.
Fasting is a great solution for many to quickly reset insulin receptors to become more sensitive. Since all foods raise insulin levels, the best answer is to completely abstain from food. When we fast, we tap into stored energy, and our fat cells release fat to use for fuel.
Fat burning – the fat cells can finally release stored energy to use as fuel
Fasting normalises insulin receptors to help your cells be able to better use blood glucose.
Fasting normalises leptin receptors. Leptin, the satiety hormone can become resistant if we constantly overeat, and fasting can help reprogram us to tell when we are satiated.
Ghrelin the hunger hormone is often dysregulated with poor nutrition or blood sugar issues. Even after weight loss, your ghrelin ‘set point’ might still be programmed for your higher weight, meaning your thinner body still has your fatter bodies appetite!
Burning fat or ketones is a cleaner burn for the mitochondria in the cells, producing more energy and less oxidative stress. Burning ketones are a more stable source of energy, and spike insulin less than glucose.
Cellular cleaning: fasting increases a process called apoptosis, and autophagy, forms of cellular cleansing. which renews cell populations, essential for good health. "Simply put, fasting cleanses the body of unhealthy or unnecessary cellular debris." - The Complete Guide to Fasting, Jimmy Moore, Jason Fung
Gut health - A stressed gut can't digest effectively, is often leaky and prone to inflammation. Giving digestion a break, ramps up healing.
Lower triglycerides as a result of eating less carbohydrates, and less insulin spikes
Lower inflammation and oxidative stress
Lower cortisol levels: Stress in any form increases cortisol levels which raise blood sugar. If the body has a stable source of fat as fuel, the stress response will not be ignited.
Fasting is one of the few things proven to stimulate adult neurogenesis, the growth of new brain cells
Misconceptions About Fasting
There are a few common misconceptions about fasting. Many people think it fasting will slow metabolism, and increase fat storage, or that muscle will be lost. None of these are true!
“Our bodies do not shut down in response to short term fasting. in fact, metabolism revs up, not down during fasting. This makes sense from a survival standpoint. If we do not eat, or bodies use stored energy as fuel so that we can find more food.” - The Complete Guide to Fasting, Jimmy Moore, Jason Fung
"The human body evolved to survive periods of fasting, we store energy as body fat and use this fuel when food is not available. Muscle, on the other hand, is preserved until body fat becomes so low that the body has no choice but to turn to muscle, this will only happen when body fat is less than 4%" - The Complete Guide to Fasting, Jimmy Moore, Jason Fung
How to fast
Before you begin, you need to expect your first few attempts might be tricky or uncomfortable. To prime your body for fasting, it’s best to help your body become fat adapted, and able to use fats for fuel. This involves eating a higher fat, low carb (HFLC) diet to help lower your blood sugar and insulin levels, and enable your fat cells to release fat, so your body starts to use ketones for fuel. Fasting works best coupled with a HFLC diet. A high carb, high sugar binge post fast will undo all of your good work!
An even better way to hack this is to try Dave Asprey’s invention of Bulletproof intermittent fasting. This entails drinking high fat bulletproof coffee (or bulletproof style drink) with no carbs or protein. For those who struggle at the thought of not eating, or have some blood sugar issues, this can be a great solution to tell your brain you are full, so you don’t struggle with cravings. Bulletproof coffee has the unique benefit of medium chain triglycerides (MCT) oil (exogenous ketones) which helps push you into ketosis, so you are a fat burning machine.
Ghrelin, the hunger hormone, rises and falls in a natural circadian rhythm and is lowest around 8:00am, and highest 8:00pm. Correspondingly, hunger is lowest in the morning, and the easiest way to begin fasting is to skip breakfast. IT can be much harder to skip dinner and go to bed hungry.
Who Should and shouldn’t fast?
Those who benefit most from fasting are people who are unwell, highly stressed (if you are stressed your body will often have compromised digestion), traveling, obese, or just want to improve their health. Children, pregnant women, and anyone suffering from Hypothalamus-Pituatary-Adrenal Axis Dysregulation (formerly termed adrenal fatigue) should avoid fasting.
‘A little starvation can really do more for the average sick man than can the best medicines and the best doctors.' – Mark Twain