❖ Mark Hurley >> Anti-Aging ❖
Fasting has always been beneficial to the body in terms of rest and recovery. It allows the body to recoup after the stress of digestion and assilimation. There is no doubt that fasting can shred fat - often at a fast rate. There is, however, a dark side to fasting just like any other medium - in excess. The practice of fasting has increased in recent years due to a wealth of information in this technological age.
There are countless studies portraying the benefits of fasting, however, the other side is not touched all that often. Here, I will outline some of the negative aspects of fasting that could potentially be a hindrance to your fat loss goals. Everyone has a unique chemistry and metabolism. Whether fasting becomes a negative depends heavily of your bodily chemistry as I will explain in the following sections.
Fasting certainly initiates the fat burning process because the organ system shifts its energy from an active state to a more passive state. Digestion is an active process that requires tremendous amounts of energy to carry out. The liver, gallbladder, and pancreas must all work in sync to direct these processes so that body can grow, develop, and recharge. The entire organ system is intricately connected in a chain of processes that influnce fat burning capabilities. Although fasting allows the organs to rest and recharge to optimal capacity, there is a certain limit that defines the line between fat loss and fat gain. The limit depends on the bodily need for energy conservation.
We continually need to assimilate nutrients for growth or repair of bones, connective tissue, and muscles. Without sufficient micro-nutrients, our bodies divert to starvation mode as a defense mechanism for survival. The thyroid relies on nourishment via a healthy balanced diet. Obtaining an array of antioxidents, co-factors, enzymes, vitamins, and minerals supports the growth and development of the thyroid. The metabolism ramps up when the nutritional demand of the body is met. Otherwise, energy must be conserved or created elsewhere to manage the functions of the body.
Suppose you are on a dessert island with no access to food or water. Initially, stress kicks the body into overdrive to find water and food before starvation ensues. If the body already has sufficient fat reserves or glycogen storgage, then fat loss is accelerated to extract glucose. Carbohydrates and sugar are catalysts to fat storage. This means that there is a two way path between fat storage (via excess glycogen) and glucose creation.
Once fat burning is accelerated, there will be a large spike in triglicerides or fatty acids depending on the initial metabolic rate. Fat reserves convert to its precursor - glucose - as a source of fuel. This explains why a ketogenic diet could raise blood glucose levels. Once the body attains higher efficiency, glucose can be metabolized at a faster rtae.
Consider now that the body had low glycogen reserves to begin with and a low body fat percentage. For this case, the body recongizes this and conserves the needed energy by lowering metabolic processes. This allows fat storage to be sustained for a longer period. Since there is a direct relationship between excess fat loss and stress, cortisol secretion will halt slightly as the body tries hard to sustain itself rather then enter catabolic mode.
A higher metabolism causes the threshold for stress and catabolism to close in at a faster rate. This leads to a shorter time period in terms of self preservation mode. In other words, the speed of transition from benefits to drawback is directly proportional to metabolic rate. The inevitable outcome of excess fasting - cortisol secretion - creates a viscous cycle of muscle atrophy and unstable glucose levels.
Cortisol is a stress hormone that provides us with a steady supply of glucose as we wake up in the morning. In moderaton, cortisol will not impact the ability to shed fat. In fact, cortisol helps sustain energy levels to faciliates the burning of excess calories. Burning fat is not necessarily a question of how many calories we consume. If our body extracts plenty of nutrients, then the metabolic rate increases. If we eat too few calories with a low nutrient density, then the body spares fat to preserve energy reserves. This means that the output (rate of calorie burning) decreases as the input (calorie intake) falls too low. Keeping the input (caloric intake) reletively fixed while steadily improving the diet causes the output (calorie burning) to increase.
Suppose that you consume a fixed amount of calories per day. Each month, the diet is adjusted from poor to optimal. You'll begin to notice that although calorie intake is fixed, fat-loss becomes more noticable because the organ system ramps up its production. The distinction between a poor diet and healthy diet is subjective, however, we can all agree that mcDonalds is not the ideal diet. It's certainly fine to indulge once in a while on a big mac or mcflurry. A healthy diet is defined based on macro-nutrient ratios, nutient density, and other factors. Nutrients increase the overall efficiency of the body, which in turn increases the output (calories burned).
The reason poor diet contributes to fat gain is due to inflammation, which triggers the release of cortisol. Cortisol not only regulates the gluconeogenesis cycle, but it combats inflammation. By creating glucose via amino acids or muscle break-down (catabolism), the body can use the extra energy to support the demands for inflammation.
High cortisol levels reduce the ability to shed fat. There is a certain tipping point where cortisol antagoizes hormone levels and adds excess glucose in the system. When the body is rampent with stress, cortisol - a stress hormone - needs to target the infammation arising from within. To do so, it can create glucose by breaking down muscle tissue to extract amino acids for the conversion process to occur. Over time, glucose metabolism becomes sluggish, resulting in the potential for weight gain.
The thyroid gland is a "master gland" regulator of matebolic processes. Without sufficient thyoid hormones, the body slows down. You could think of the thyoid as a body clock for biochemical processes. Fasting is very beneficial to the liver, which works in synergy with the thyroid. Fatty liver disease contributes to weight gain for multiple reasons, including the following:
Ironically, fasting can reverse fatty liver or promote it. This occurs for the same reason it is not advised to quit smoking rapidly, but rather taper off in smaller increments. If the liver is already in critical condition, then fasting could create a very high toxic load that worsens the condition. This causes the metabolism to shut down and creates a viscous cycle.
Not all carbohydrates are equal. Complex carbs broken down at a slower rate for sustained energy whereas simple carbs are quick sources of energy. Glycogen is a reservor of energy that is created once insulin helps transfer glucose to the liver for the conversion process via glucagen. Glycogen also supports the conversion of inactive t4-thyroid hormone to active t3 hormone. The body needs some carbohydrates to function. All three macro-nutrients ignite the engine that speeds up bodily processes. Finding balance is key to maximize the efficiency of the body - creating a fat burning machine.
If glycogen is depleted due to rigorous exercise or extended fasting, the body transtitions into a state of ketosis. Although ketosis supplies the brain with fat as an efficient source of fuel, glucose is continually created via cortisol. Intense exercise and a diet void of carbohydrates are a bad combination. The body has a very high demand to regulate all biochemical processes. Glycogen is a fuel source that reduces recovery time and prevents the need for cortisol to create extra glucose.
Burning fatty acids for fuel is one part of the equation. What if every muscle fiber in the body is torn due to an intense exercise session? Would the body fare well producing just ketones? It depends on body fat levels, hormone levels, etc. Higher hormone levels such as HGH, testosterone, and DHEA reduce recovery time. If the energy demand for muscle repair is lower, then less cortisol will be secreted to combat inflammation. Excess fasting lowers hormone levels, which in turn increases stress by increasing recovery time. Glucose acts to save the adrenal glands from cortisol discharge. High cortisol is linked to lower thyroid output and a host of other problems.
It is really impossible to determine exactly when fasting becomes problematic. We can, however, listen to our body to gauge an ideal fasting range to support optimal matabolism. Generally, fasting beyond two to three days can pose issues with regards to blood glucose levels and brain oxygenization. In fact, excess fasting may cause seizures due to the lack of oxygen supply to the brain and low glucose levels. Anything in excess is inherently negative, but it is hard to define such a limit. Just as the body adapts to a rigorous exercise routine, the body also adapts to diet.
Jumping into an extended fasting state suddenly shocks the body because it adjusts to our food intake patterns. Transitioning smoothly leads to a more efficient shift in energy from an active (processing) state to a passive (healing) state.
A vegan, for instance, who suddenly decides to eat animal protein will suffer because stomach acid and pepsin production halts to conserve energy. Stomach acid helps break down animal proteins. Wolves have a higher supply of stomach acid due to their carnivore nature. This is also why wolves can eat raw meat without much of a risk of food poisining.
If we give the body time to adjust to a change in our daily routine or habits, then less energy will shift to deal with the added stress. To reap the benefits of fasting, take the process slowly. Rather than undergo a long extended fast after a heavy laden diet, introduce shorter intermittant fasts.
Fasting has been shown in numerous studies to increase growth hormones levels, which are associated with lean muscle mass and youthfulness. This is partly a defense mechanism because growth hormone levels preserve lean muscle mass while improving mental alertness, clarity, and working capacity. This effect tends to set in quite early in the fasting process - roughly 16-24 hours, and last up to three days. The surge in growth hormones, however, does not last once the body becomes depleted of energy reserves. The body must then enter self preservation mode to maintain energy.
The best practice is to fast moderately to maximize its fat burning potential. Generally, 1-2 days of fasting is sufficient to yield benefits. Beyond that point, the benefits start diminishing and reverse in the other direction. The liver detoxifies the bloodstrem continuously, which is a huge burden.
Fasting is detrimental to the liver under certain circumstances. Pesticides and many other toxins are fat insoluble. This means that pesticides reside in fatty tissue until the fat cells shrink. Once excess fat is burned off, the toxins need to be eliminated. There are various pathways to achieve proper elimination. The liver and gallbladder work hard to filter toxins and rid the body of waste products. Bile - a byproduct of the gallbladder - helps flush toxins through the intestinal tract. Obtaining enough dietatary fat is very important for detoxification.
Fasting accelerates the fat burning process in the initial stages, however, a high toxic load could deccerlerate or even reverse the process. Losing too much fat in a short period puts immense strain on the liver. The thyroid relies havily on the liver to increase metabolic rate. To achieve balance within the body, be cognizant of your bodily needs and only fast when approprate. Short term fasting reduces the burden on the body, yet long term fasting increases it. Finding the divding line takes awareness.
To sum it up, fasting has numerous beneftis but also can be detrimemtal depending on the initial state of the body and the duration of the fast. Easting healthfully and avoiding stress help minimize the release of cortisol - a catabolic hormone, in excess. A poor diet will reduce metabolic rate in the long run regardless of caloric intake because the efficiency of the body will decrease. Being cognizant and aware of our body will prevent any transition from a fat-burning stage to a fat-promoting stage. The entire organ system needs a balance of macro-nutrients, micronutrients, etc, to carry out the many biochemical processes.