My girlfriend used to joke with me when I started taking paleo seriously that after taking out this food and that food eventually the diet I would be on would just be no food. She ended up being right! At least partially.
The benefits of fasting and calorie restriction have been known for decades to the scientific community. Populations like the Okinawans which are known for their longevity seem to have calorie restriction behavior as well. Animal models have even shown an increase in lifespan of up to 200%!
So am I suggesting you close this window right now and clean out your pantry? Hardly. It turns out you might not have to starve yourself to get these benefits. At least not forever.
Enter intermittent fasting
Intermittent fasting is the practice of not eating for a fixed amount of time (the fast). After the fast has ended, eating continues as normal. Some popular protocols for this include leangains (16 hour fast, 8 hours eating per day), eat stop eat (24 hours once a week) and even religious holidays like Yom Kippur.
Research has shown that fasting for short periods of time can have the same effects as calorie restriction on a cellular level. In fact, our bodies are programmed to behave like this. The answer lies in our evolutionary past.
Feast and Famine
Up until the creation of the modern agricultural system, human beings were subjected to intermittent fasting all the time – and not by choice. As a hunter-gatherer, it could be days before a kill could be made or some nutrient rich plant foods could be found. As we evolved, our bodies developed systems to maintain the health of our cells during the times when food could not be found.
In times of plenty, the hormone insulin determined the majority of activity within the cell. We’ve covered insulin before in a number of posts but on a very basic level it exists to tell our cells to grow. In the presence of insulin, nutrients are added to cells, new cells are created and pro-inflammatory activities occur. All very necessary activities if done in moderation.
However, in times without food, insulin is downregulated and conservation becomes the primary goal. This is accomplished through the release of Human Growth Hormone (HGH). During fasting, the genes for HGH secretion are ‘turned on’ epigenetically, boosting the rate up to 2000%. The goal of this is to increase repair, which is less costly from a metabolic perspective than growing new cells. It also increases the use of fat as a fuel source, preserves muscle tissue and turns on the genes for cell death in non useful cells (often fat cells).
Using Intermittent Fasting for Survival
Because of the cultural norms in the western world, most people are never in a true fasted state. Eating 3 meals a day, riding the blood sugar rollercoaster and eating high glycemic foods like bagels first thing in the morning prevents fasting from ever taking place.
Seeing the benefits of fasting can be as easy as skipping one meal a day to start off. Skipping breakfast can take advantage of the average 8 hours of fasting you are doing every night by sleeping. If you eat a late dinner at 8PM, say, skip breakfast, and eat lunch at noon, you will have just completed a 16 hour fast.
The applications for this in a true survival scenario are myriad. First, food supplies can be conserved if the window for eating is smaller. Not having to worry about eating first
thing in the morning is a load to be taken off the mind. The benefits of increased HGH for your health will keep you strong, prevent aging and accelerate repair of any wounds. Not to mention protect from muscle loss to keep your ability to move and defend yourself.