Everything in nature occurs in cycles…
Night turns to day: the moon waxes and wanes, tides go in and out, seasons roll, rivers flood and dry…
Our bodies evolve and adapt in a similar way in which the natural world does: we’re constantly subject to such cycles.
As a result, the key cycles that affected the development of our human bodies were the cycles of feast and famine and exercise and rest.
Our ancestors in the Paleolithic period didn’t have the constant food availability as we do today. They lived in conditions where they’d feast after a successful hunt or in seasons when fruit was abundant.
Interspersed with the feasts were periods of famine from severe winter, summer drought conditions or unsuccessful hunts. During those bleak days, survival was solely dependant on the ability to store calories from feast periods and being able to turn these stored calories into energy during times of famine.
Contrast these conditions to our modern world.
Today, we live in a time of round-the-clock food availability.
As previously noted, the number of eating occasions in the USA and the UK has climbed noticeably in recent years. Three meals a day is only the beginning, and for many, having five or six meals a day is standard practice. How many people do you know who regularly go a day or two without eating? Have you ever gone for a week without food?
Unless we’re in a war zone or something extreme, famine is no longer a part of our modern western world.
Combined with constant food availability is the change in our physical lifestyles. Chasing animals with spears while starving in the freezing cold is merely a distant food sourcing system. Nowadays, we jump in the car and head to the fast food drive-through or take something out of the freezer and pop it into the microwave and eat it on the couch while playing a video game. We live a life of sedentary ease and non-stop food abundance. Grok the caveman would be jealous.
Metabolic researchers believe that these changes of constant food availability and lack of intense physical activity have stalled an important metabolic cycle in our bodies, and this causes the range of metabolic diseases (obesity, insulin resistance, NAFLD, diabetes, hypertension, cancer, Alzheimer’s, etc.) seen today.
As Chakravarthy and Booth note in their research, ancient man was genetically selected to have a “thrifty gene” from the constant cycling of fuel stores, blood insulin, insulin sensitivity and metabolic proteins driven by the constant cycles of feast-famine and physical activity-rest. So, our bodies evolved to have a natural metabolic state that required the constant cycling of the storage levels of glycogen and triglycerides, which was driven by the feast- famine and physical activity-rest cycles. This is what keeps us healthy. It’s like the other cycles of nature. Things wouldn’t work so well if the seasons got stuck in summer or winter.
What happens instead to our bodies in modern Western societies with continuous food abundance and sedentary lifestyles? We eat, rest and store fuel without the stimulus for utilizing it.
Our bodies are very efficient at storing fuel, especially in the calorie-dense environment we have created for ourselves. But we rarely if ever go through the cycle of drawing down our energy stores of glycogen and triglycerides through the stimulus of famine or intense physical activity.
Our bodies do not receive the regular benefits of this required metabolic cycling that our system is designed to experience, and instead the cycle stalls with continuous high levels of glycogen and triglycerides stored in our muscles and liver. As a consequence we tend to develop the chronic metabolic diseases noted above.
Intermittent fasting is a way to help create this natural metabolic cycle in our bodies. Please remember that in conjunction with intermittent fasting, regular physical exercise is also required to obtain the full benefits.
How Intermittent Fasting And Metabolic Cycling Feels In Your Body
Probably the most impressive part of the PURE 5:2 Transformation is the feeling in your body and your mental and emotional state when you start to experience repeated metabolic cycling. This is what happens when your body is allowed to burn fat. If you have been eating a pure high nutrient density diet, then your body has the essential phytonutrients, antioxidants, and enzymes that it needs to run properly and easily handle the cycles. It’s like accelerating in your car when it’s perfectly tuned.
Things really change when you fast long enough to burn up the glycogen stores in your muscles and liver. Your body has approximately 900 calories worth. After this point your body can enter a state called ketosis. During ketosis your brain and body is fuelled differently by burning fat rather than just burning glucose as you normally do. This is just one of the metabolic cycling benefits.
What happens when you do an intense workout in the fasted state?
Let me tell you from personal experience, it’s a feeling unlike any other. Also, research has proven how working out in a fasted state can lead to efficient fat burning and more rapid weight loss. Don’t even think about drinking that sugar- sweetened “athletic” drink before working out!
This is what the PURE 5:2 Transformation is all about.
Twice a week you get to experience a complete metabolic cycle in your body. Everybody has different needs and tolerances regarding the proper frequency and depth of the cycle. But, the key point is this: by going through the metabolic cycle you get to experience a transformation. You will experience autophagy as the cellular debris is cleansed from your body.
You will experience the cycle of consuming stored glycogen and triglycerides. After that, if you have been eating a low-carbohydrate diet, you will burn off all of your glycogen reserves and will enter ketosis. In ketosis, your body actually runs more efficiently and makes more energy per oxygen molecule used. It alters brain function, and ketosis is used as a natural therapy for certain neurological conditions such as epilepsy. Once your body has developed metabolic flexibility and adjusted to burning fat and entering ketosis, you will probably experience far sharper and crisper mental clarity than you have ever experienced before. Indeed, fasting has always been associated with increased spiritual clarity.
Our Ancestors, The Hunter-Gatherers
Think about the evolutionary natural selection scenario. Better yet, imagine that you are the caveman or cavewoman who has not eaten for days. It is the end of winter and your tribe has run out of food. The snowfall finally stops and now the hunt begins. You head out with 3 other villagers, on foot, armed with arrows and spears, to track and kill food for the starving tribe. Imagine your body at that point. No food for days. Freezing cold. Shivering hard to stay warm. (No warm car and drive-thru coffee and Egg McMuffin to start the day.) These are feelings that we don’t have too often in modern times. You head out with your tribal family who are all just as cold and hungry as you are. As you cross a frozen lake to get to the best hunting ground, your party is ambushed by a pack of six hungry wolves. Big ones. At this point you are all sprinting towards the tree line at the edge of the frozen lake to get to the trees before the wolves get to you. Let me ask you a question: How alert and alive will you be feeling in your body? Will you have the energy that you need or will you complain about no breakfast and say you need an energy bar before a workout?
If you didn’t have the mental acuity to be crisp and alert, and the burst of energy to outrun the wolves, then you were probably eaten. Over eons, the people who didn’t were definitely the ones who were eaten, or just were unable to feed themselves and didn’t pass on their genes. What that means is that the bodies that we are blessed with today are the ones that were selected to endure metabolic cycling and survive in feast/famine conditions and produce extreme physical output when needed. Which was often. That means you, too, can have an intense workout in the fasted state and have physical energy and mental clarity as you have never experienced before. This is the state that your body is genetically programmed to be able to enter. Outthink and outrun the wolves. Until you have experienced this you can’t imagine how it feels. But it’s real, and since this genetic programming lies latent within you, it means that you, too, can experience feeling this way. Perhaps you can try it twice a week?
Of course, you outran the wolves and dispatched a few of them with arrows once you climbed the trees. After that, you successfully hunted and killed a mastodon, then trekked 10 miles back to the village to summon help to cut up and retrieve this 4-ton prize. Now ask your caveman self a question. Did you eat a lot over the next few days? Did you worry about your waist size going up an inch, or feel guilty if you missed a few workouts? Imagine how it must have felt in your body to go from starving and exhausted from the hunt, to relaxing around the fire gorging on freshly roasted mastodon brain and liver. Yes, you would eat the prized, highest fat, most nutrient-dense organs first. Then, you would eat and eat, until you could eat no more. The next few days you would probably continue to feast and probably gain 10 pounds. It would feel wonderful to gain the weight because the stored energy meant survival and the ability to reproduce.
This is how our ancestors lived and experienced metabolic cycling. Only 500 generations ago, this is how humans were naturally selected and these selection pressures are what created the bodies that we have today. “A better understanding of many modern health problems will emerge when we consider that most of human evolution took place when our ancestors were hunter-gatherers.”36
Scientifically Proven Health Benefits of Intermittent Fasting
Fasting has been a basic part of health and wellness practices in many different cultures throughout the recorded history of mankind.37 This timeless tradition may be partially rooted in cellular and biochemical processes we are now beginning to understand in modern scientific terms. Intermittent fasting has been the subject of numerous controlled scientific studies and has been shown to have many different benefits. Here are some of the documented health benefits that you can expect from intermittent fasting.
Weight loss is one of the most obvious and desired benefits of intermittent fasting. In a 2009 study at the Department of Kinesiology and Nutrition at the University of Illinois, 16 obese test subjects were put on an intermittent fasting weight loss program.38 On the fast days their food intake was restricted to 25% of normal, and on the non-fast days they were allowed to eat all they wanted. This protocol did differ from the 5:2 program since every other day was a fast. So, if you are really interested in more rapid weight loss you could increase the number of fast days to match this study. The weight loss trial lasted for 8 weeks, after a 2-week control period. During this time, the subjects lost an average of over 12 pounds each. For half of the period the subjects were able to self select their food intake. Their weight loss during this period was the same as it was when the researchers controlled their food. This indicates that intermittent fasting is a diet program that is easy to follow.
In addition to losing weight, the test subjects also had significant improvements in their cardiovascular health measurements. Their total cholesterol, LDL cholesterol and triaclglycerol concentrations decreased by 21, 25 and 32% on average. Also, their systolic blood pressure decreased by 8mm Hg. on average.
Another study at the same lab compared weight loss with a constant calorie restriction diet versus weight loss through intermittent fasting.39 They found that both programs yielded the same total weight loss, however, with intermittent fasting the test subjects lost less fat-free lean mass (muscle) than the subjects on a constant calorie restriction. This is a key finding, which verifies that intermittent fasting is a healthier way to lose weight.
In a wide range of species, the only environmental variable that has been shown to significantly affect the rate of aging is caloric intake. Reducing food to a level typically 30 to 40% less than that which would normally be consumed voluntarily results in a slowdown in the rate of aging and increase in maximum lifespan. This caloric restriction has also been shown to reduce kidney disease, cancer formation, and lessen neuron degeneration that is typical of Alzheimer’s and Parkinson’s disease. This is good news, but in practice it is extremely difficult to live a normal life on 60–70% of the food that you would normally eat. Very few people are really willing to endure such a regime long term!
However, researchers from the National Institute of Aging have found that when lab mice are fed an intermittent fasting diet regime with no restriction in total calories (which allows the mice to retain their normal weight), this resulted in the same benefits as a caloric restriction regime on their glucose and insulin levels and neuron resistance to excitotoxic stress.40,41 In addition, researchers at UC Berkeley have shown that intermittent fasting reduces cancer risk and cell proliferation rates in mice as much as calorie restriction does.42 These studies all indicate that intermittent fasting can provide the same health benefits as calorie restriction without the long-term drawbacks of eating 30-40% less food.
Enough talk about mice! What about research on humans? One of the key markers of metabolic health is insulin sensitivity. When diabetes develops, the body becomes less and less sensitive to insulin, and the pancreas must produce it in ever increasing quantities. Eventually, the pancreas fails to produce the insulin needed. So, the results of a study on healthy human subjects at the University of Copenhagen give hope for the usefulness of intermittent fasting in preventing the onset of diabetes.43 In this study, eight healthy young men were put on an intermittent fasting regime for two weeks. During the feeding portion they ate enough so that their weight remained constant. This study showed that intermittent fasting increased the insulin sensitivity of the whole body. They concluded that cycles of feast and famine are important as an initiator of “thrifty genes” leading to improvements in metabolic function.
One cellular response to fasting is the activation of autophagy (from the Greek, “auto” oneself, “phagy” to eat). This is a process in which the cell self-digests its own components. This self-digestion not only provides vital nutrients to cells during fasting but also allows cells to rid themselves of undesirable components such as invading microorganisms, malformed or worn out proteins or damaged organelles (sub-structures within a cell). This self-cannibalistic process of autophagy keeps cells from becoming choked with trash and malfunctioning. It is triggered by fasting, exercise and certain dietary compounds and is now being seen as a biological pathway that functions to promote health and longevity. Proper autophagy is believed to help protect against a range of diseases, including infections, neurodegeneration, cancer, heart disease and aging.
There have been many more studies. Intermittent fasting has also been shown to reduce inflammation in asthma patients and reduce the risk of coronary artery disease. In addition, it is a way to boost the level of human growth hormone (HGH), which typically declines as we age. You can see the pattern here: intermittent fasting has been scientifically proven to work. All of these disease prevention benefits are wonderful, but what is really exciting about intermittent fasting is the way you can feel right now in your body when you put it into practice!
In summary, current research has shown these important and often unknown highlighted benefits of intermittent fasting:
◆ Normalizing insulin sensitivity, which is critical for optimal health as insulin resistance is a primary contributing factor to nearly all chronic disease, from diabetes to heart disease and even cancer
◆ Normalizing ghrelin levels, also known as “the hunger hormone”
◆ Promoting human growth hormone (HGH) production, which plays an important part in health, fitness and slowing the aging process
◆ Lowering triglyceride levels
The information above is an excerpt from PURE 5:2 Transformation In 21 Days…The Complete Guide To Healthy Intermittent Fasting.