Intermittent Fasting for Weight Loss

It is perhaps the oldest and most powerful dietary intervention. So how does it work?

Fasting is one of the most ancient and widespread healing traditions in the world. Hippocrates of Cos (c 460 – c370 BC) is widely considered the father of modern medicine. Among the treatments that he prescribed and championed was the practice of fasting. Hippocrates wrote: 'To eat when you are sick, is to feed your illness'. The ancient Greek writer and historian Plutarch (cAD46 – c AD 120) also echoed these sentiments: 'Instead of using medicine, better fast today'. Ancient Greek thinkers Plato and his student Aristotle were also staunch supporters of fasting.

Many people today are re-discovering this dietary intervention as it can carry huge benefits if it is done right: weight loss, increased energy, reversal of type 2 diabetes and many other things. Plus, you’ll safe time and money.

So what is Intermittent Fasting?

Anytime that you are not eating, you are fasting. For example, you may fast between dinner and breakfast the next day, a period of approximately 12-14 hours.

Consider the term “breakfast”. This refers to the meal that breaks your fast – which is done daily. Rather than being some sort of cruel and unusual punishment, the English language implicitly acknowledges that fasting is performed daily, even if only for a short duration.

Intermittent fasting is a diet regimen that cycles between brief periods of fasting, with either no food or significant calorie reduction, and periods of unrestricted eating. It is promoted to change body composition through loss of fat mass and weight.

First, let’s understand what happens when we eat.

When we eat, more food energy is ingested than can immediately be used. Some of this energy must be stored away for later use. Insulin is the key hormone involved in the storage of food energy.

Insulin rises when we eat, helping to store the excess energy in two separate ways: glycogen and fat. Glucose (sugar) is linked into long chains, called glycogen and then stored in the liver. There is, however, limited storage space; and once that is reached, the liver starts to turn the excess glucose into fat. This process is called De Novo Lipogenesis (meaning literally Making Fat from New).

Some of this newly created fat is stored in the liver, but most of it is exported to other fat deposits in the body. While this is a more complicated process, there is no limit to the amount of fat that can be created.

Now, what happens when we stop eating?

The process goes in reverse when we do not eat. Insulin levels fall, signaling the body to start burning stored energy as no more is coming through food. Blood glucose falls, so the body must now pull glucose out of storage to burn for energy. This happens because the period of fasting results in several changes in the levels of various key hormones in the body- insulin, growth hormone and norepinephrine.

During the period of intermittent fasting while the levels of insulin go down, those of growth hormone increase, both resulting in fat burn. Additionally, norepinephrine or noradrenaline is sent to the fat cells, breaking them down in fatty acids, which can be directly burned for energy.

So, that the body only really exists in two states – the fed (insulin high) state and the fasted (insulin low) state.

Either we are storing food energy, or we are burning it. It’s one or the other. If eating and fasting are balanced, then there is no net weight gain.

To restore balance or to lose weight, we simply need to increase the amount of time we burn food energy. That is intermittent fasting.

In essence, fasting allows the body to use its stored energy. After all, that’s what it is there for. The important thing to understand is that there is nothing wrong with that. That is how our bodies are designed.

Intermittent fasting causes an immune response that repairs cells and produces positive metabolic changes such as reduction in triglycerides, LDL cholesterol, blood pressure, weight, fat mass and blood glucose.

Moreover, because dieters are restricting the hours of their food consumption, they're automatically consuming lesser amount of calories than before. This is another reason intermittent fasting may lead to weight loss.

Intermittent Fasting Methods

There are several different ways of doing intermittent fasting — all of which involve splitting the day or week into eating and fasting periods.

During the fasting periods, you eat either very little or nothing at all.

These are the most popular methods:

· The 16/8 method: It involves skipping breakfast and restricting your daily eating period to 8 hours, such as 12–8 p.m. Then you fast for 16 hours in between.

· Eat-Stop-Eat: This involves fasting for 24 hours, once or twice a week, for example by not eating from dinner one day until dinner the next day.

· The 5:2 diet: With this method, you consume only 500–600 calories on two non-consecutive days of the week, but eat normally the other 5 days. 

By reducing your calorie intake, all of these methods should cause weight loss as long as you don't compensate by eating much more during the eating periods.

Many people find the 16/8 method to be the simplest, most sustainable and easiest to stick to. It’s also the most popular.

However, people with advanced diabetes or who are on medications for diabetes, people with a history of eating disorders like anorexia and bulimia, and pregnant or breastfeeding women should not attempt intermittent fasting unless under close supervision of a physician who can monitor them.

To avoid an unpleasant, and at times even an unsafe experience, don’t be afraid to rely on a little support from an experienced coach and support tools.