Fasting has always been a natural part of human existence. Our distant ancestors experienced periods of low food availability. Our bodies have evolved to adapt to this situation. When periods of starvation faded, ancient cultures learned to use periods of voluntary fasting - a time of cleansing, detoxification or purification.
In the last 50 or so years, even with the ancient understanding of the positive benefits of fasting, it has not been incorporated into our western lifestyle.
Fasting is a powerful tool for reversing insulin resistance and stubborn weight loss, has protective effects against Alzheimer's and Parkinson's, and can protect against liver disease, heart disease, and cancer. Fasting boosts our metabolism, increases growth hormone and increases our energy.
In this article, we are going to explore why fasting has so many benefits, debunk the most common myths surrounding it and share ways to incorporate fasting into your life.
Many people eat out of habit, comfort or boredom more than true hunger - fasting helps you realize what true hunger feels like and break out of this cycle.
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What happens when we eat
When we eat, insulin increases, which stores sugar in the liver and produces fat in the liver.
What happens when we fast
When the body is not consuming food, we are “fasting”. Insulin decreases, we burn stored sugar and body fat.
Lower insulin causes diuresis which rids the body of excess salt and water, reducing bloating, which makes us feel lighter.
During fasting, adrenaline increases, our metabolism speeds up and our body is getting energy from burning fat rather than burning food.
The majority of people who fast report feeling increased energy levels. Studies confirm this. In one study, after 4 days of fasting, resting energy increased by 12% and growth hormone secretion doubled.
Why is our body coming alive when we aren’t consuming food?
From an evolutionary point, it makes sense. Our bodies are increasing our energy so we can go out and find our next meal.
Myths about fasting
1. Fasting = Starving
During starvation, our bodies shut down. During fasting, our bodies rev up. Our bodies use stored energy as fuel. This is why we carry body fat.
2. Fasting burns muscle
When food is not available we use body fat for fuel. Muscle is preserved until body fat becomes so low, our body has no other choice. This is typically when the body fat percentage reaches 4%.
3. Fasting causes low blood sugar
If we fast more than 24-36 hours our glycogen stores become depleted. The liver makes glucose, using glycerol that's a by-product of the breakdown of fat. We don’t need to eat glucose for blood glucose to remain normal.
4. Fasting ultimately results in over-eating
Studies show caloric intake increases on the first day after ending a fast, but there is still a net deficit of calories. Appetite tends to decrease as the length of the fast increases.
5. Fasting deprives the body of nutrients
During fasting, the body reduces losses to keep needed nutrients. Since no food is going into the stomach, stools decrease and we don’t lose as many nutrients. For extended fasts, it’s a good idea to take a general multi-vitamin.
Contrary to popular belief, eating less and exercising more does not always work. If you have insulin resistance, consistently high insulin levels make it difficult for the body to access fat stores. This can lead to a vicious cycle of eating which produces insulin, but the cells do not use the food for energy so sugar ends up being stored as fat. You feel tired and hungry and crave more food.
Fasting is the best way to decrease insulin levels.
During fasting metabolism increases to maintain normal energy levels, adrenaline and growth hormone increase to maintain energy and muscle mass. Blood sugar and insulin levels decrease as the body changes from burning sugar to burning fat. This helps address insulin resistance.
Fat loss during a fast average 1/2 pound per day. Anything above this is typically water weight that will be regained upon eating.
Autophagy is a form of cellular cleansing where diseased or broken down cell parts are discarded so the body can generate new, healthy cells. When this process does not happen, it’s believed disease such as cancer can occur.
If the body senses food is available, there is no need to kill off poorly functioning cells.
During fasting, the body is forced to prioritize which cellular parts to keep and it discards the unhealthy cells.
Dr. Thomas Seyfried, a biology researcher and professor at Boston College promotes a yearly 7-day water fast to promote autophagy and prevent cancer development.
Eating cholesterol does not raise blood cholesterol, nor does dietary fat. The only reliable way to reduce LDL levels is to reduce the liver’s production of it. Studies have shown alternating day fasts can reduce LDL by 25%, which is half the effect of statin medications.
Who should not fast
If you are malnourished or underweight, under 18 years of age, or pregnant or breastfeeding, you should not fast.
If you suffer from gout, type I or II diabetes, gastroesophageal reflux disease or are taking medications, talk to your doctor. Always consult with your health care professional before undertaking a fast.
We recommend only consuming non-caloric drinks such as water, herbal tea, or green juices. Sugar, honey, fructose, agave, etc are prohibited. For longer fasts, homemade bone broth with added sea salt can help prevent headaches and restore nutrients, while helping you feel full.
2-day fast - Day 2 is typically the hardest to deal with hunger so we encourage you to fight through it and make it a longer fast.
5-14 days fasts - this allows the body to quickly adjust to fasting conditions and longer periods allow more rapid improvements. Drink home-made bone broth for phosphorus and other electrolytes and do all usual activities, including exercise which helps maintain bones and muscles.
How to deal with common issues when fasting
On non-fasting periods, diet is key
Humans have not evolved to eat highly processed foods. White flour is almost pure carbs. Foods should be recognizable in their natural state as something alive or that has grown out of the ground. Eat real food. Eat as plant-based as possible.
- Summary -
In the old times, when the harvest came in they feasted. But in the dead of winter, food was scarce and they fasted. In the past 50 years, we’ve kept all the feasting but eliminated the fasting.
There are so many health benefits to fasting and to detoxing. We hope you share your experience with us.
It's important to remember if you feel unwell, stop your fast.