Over the past decade searches for the term ‘intermittent fasting’ has increased by over 10,000 percent, but there is nothing new about fasting.
Periods of voluntary abstinence from food and drink, what we call intermittent fasting, has been practiced since ancient times, by people around the world. Hippocrates, the father of modern medicine, believed fasting facilitated the body to heal itself. Fasting is now widely appreciated for its beneficial effects on human metabolism and health.
Fasting is often mistaken for starvation, but the two differ in a crucial way. Starvation is the involuntary absence of food, over a sustained period of time, which is neither deliberate nor controlled. The consequences of starvation may lead to suffering and possibly death.
Fasting, however, is the voluntary withholding of food for spiritual or health purposes. Fasting is under our control, starvation is not.
Intermittent Fasting (IF) is a pattern of eating that gives your body a multi-hour or multi- day break from the work of metabolising.
The phrase Intermittent fasting can mean different things to different people and is often used interchangeably.
The most common methods of intermittent fasting are
Time-restricted eating refers to limiting food intake to certain hours of the day, without an effort to reduce caloric intake. Often, this is what a person is referring to when they talk about intermittent fasting. The most popular style of time-restricted eating is the “16:8” fasting method, where the entire day’s calories are consumed within an 8-hour window, leaving 16 hours for fasting, including the hours during which a person is asleep.
Time-restricted eating exploits the body’s innate 24-hour patterns, proving a down time where it can focus on cellular repair and restoration rather than digestion.
Alternate-day fasting, quite simply, involves fasting every other day, while eating normally on non-fasting days. Participants can adapt the alternate-day fast, to allow them to consume a small amount of food – approximately one-fourth of their optimal intake – on fast days. Alternate-day fasting appears to have the same effects as other variants of fasting and may be beneficial for weight loss due to its greater sustainability.
Prolonged fasting, occasionally referred to as periodic fasting, typically exceeds 48 hours. This type of long-term food deprivation can initiate an array of metabolic events, such as deeper ketosis -the body’s fat burning mode. As glycogen stores are exhausted, the body commences a clean-up programme for the cells through processes such as apoptosis and autophagy.
While most people can safely practice time-restricted eating, periodic fasting may be more appropriate to do under the guidance of a health care professional.
When we eat, we take in more food energy (calories) than we can use at the time. The hormone insulin increases, instructing our body to store some of that energy for later, either as sugar in the liver (glycogen) or body fat.
Individual glucose (sugar) units are linked into long chains to form glycogen and stored in the liver. This energy source is easily accessible, but it has a limited storage capacity.
When dietary glucose and protein levels are higher than our glycogen storage capacity, any excess is turned into fat for storage by the liver, in an almost limitless process called de- novo lipogenesis (which translates to “making new fat”).
These two food energy storage systems complement each other. Glycogen is readily available but has limited storage space. Body fat is more difficult to access but has unlimited storage space.
If we don’t eat, we choose to fast instead, the energy storage procedure goes in reverse. Insulin levels fall, telling the body to start burning the stored energy, glycogen and body fat.
Glycogen is used first because it is the most easily accessible, but once glycogen stores are depleted, the body will start breaking down body fat for energy instead.
The body only really exists in the fed (insulin high) state or the fasted (insulin low) state. It cannot exist in both states at the same time. If we are constantly snacking then we will gain wait over time, as the body spends insufficient time in the fasted state, unable to use stored fat.
If our goal is to lose weight, then we need to increase the amount of time spent burning food energy. That is the objective of fasting, it basically allows the body to use its stored energy.
Intermittent fasting has been shown to decrease insulin resistance—reducing diabetes risk and improving metabolism. During the fasting period, insulin level falls. So once the insulin level goes down – fat breakdown starts.
As soon as the carbohydrate reserves are depleted, the body flips the metabolic switch – instead of glucose, it turns toward free fatty acids as a primary source of energy. Ketosis, kicks in, creating ketones that are used as source of energy over glucose. This process breaks down the fat, resulting in weight loss.
Dr Rhonda Patrick, an American biochemist, suggests that in the absence of ready supplies of glucose and fats from meals, fasting flips a metabolic “switch,” liberating fat stores via fatty acid oxidation and ketone production while prioritising the safeguarding of lean muscle mass and function.
As such, fasting provides a mechanism that not only enhances overall body composition but also prompts the activation of biochemical processes and signalling pathways that improve human performance and physiological function, perhaps slowing the processes of ageing and disease.
Fasting also stimulates autophagy and mitophagy, the process of culling the old, dysfunctional mitochondria. So the ancient wellness practice of intermittent fasting essentially gets rid of the old mitochondria and at the same time stimulates new growth. This process of renewing your mitochondria may play a huge role in the prevention of many of the diseases we currently have no acceptable treatment — diseases of excess growth.
There is no ‘one-size fits all solution’ to achieving optimal health and fitness.
The benefits of fasting are numerous, researchers are continuing to find more reasons to fast, on what seems like a daily basis. Incorporating the use of intermittent fasting is just one of the tried and tested techniques I use with my clients, to make lasting changes to their body, and overall health.
If you would like to know more about fasting or how I can help you reach your fitness goals fill out the contact form below.