What is Intermittent Fasting?
Firstly, it is important to note that Intermittent Fasting (IF) is not a diet, it’s a way of eating. To simply put it, IF involves a longer period of no food intake followed by a relatively brief period of eating. It doesn’t change what you eat, but when and how you eat. It is a way of scheduling your meals so that you have a bigger gap between them.
However, it is certainly not a new concept. Homo sapiens have been fasting throughout their history due to tribal or communal practices, unreliable food resources or, often, for spiritual reasons. Our earliest and greatest doctors and philosophers – such as Hippocrates, Plato, Socrates, Aristotle and Galen – all praised the benefits of fasting.
“Fasting is the first principle of medicine; fast and see the strength of the spirit reveal itself.” — Rumi
What are the benefits of IF?
No wonder why IF has risen in popularity in recent years, as more and more research emerge discovering new health benefits. IF can be an easy way to simultaneously improve your general health and decrease excessive body fat. Bellow are 6 main benefits of IF:
1. Weight Loss
When you eat, your body uses glucose (sugar) as its primary source of energy and stores whatever is left over as glycogen in your muscles and liver.
When you don’t consume food, your body has no external sources of fuel to give you energy, therefore it is ‘forced’ to use your fat stores to make your body function. So, when you don’t give your body a steady stream of glucose, it begins to break down your glycogen stores for fuel. After the glycogen has been depleted, your body seeks out alternative sources of energy, such as fat cells, which it then breaks down to provide your body with energy. 
Another study  focused on the 16/8 method of IF (16 hours fasting and consuming food within an 8 hour window) showed that it significantly reduced fat mass while retaining both muscle mass and strength in active males.
2. Improve Blood Sugar Levels, lowering the risk of type 2 Diabetes
When you eat, carbohydrates are broken down into glucose (sugar) in your bloodstream. A hormone called insulin is responsible for transporting the glucose out of the bloodstream and into the cells where it can be used as energy.
Some studies have found that intermittent fasting benefits your blood sugar levels by keeping them well-regulated and preventing spikes and crashes. IF prevents the build-up of insulin in the blood stream, which allows the body to work more effectively with it and stay sensitive to its effects, Therefore they also show a decrease in appetite duo to the normalisation of the blood sugar roller coaster, [3, 4, 5]
3. Improves Heart Health
Researchers have also found that intermittent fasting could improve aspects of cardiovascular health.This is especially true due to its capacity to lower certain heart disease risk factors.
A review from 2016 reports that IF could lead to a reduction in blood pressure, heart rate, cholesterol, and triglycerides in both humans and animals, as well as increased good HDL cholesterol levels [6,7].
4. Reduces Overall Inflammation
There are a number of factors in our day-to-day lives that can trigger inflammation throughout the bodymind:
- High stress levels
- Foods: industrialised, sugar, refined carbohydrates, poor quality fats
- Exposure to cigarette smoke and pollution
- Poor sleep patterns
Inflammation may be involved in the development of chronic conditions, such as heart disease, cancer, obesity and rheumatoid arthritis. . Several studies provide promising evidence showing that IF may help reduce inflammation and fight off chronic disease. [9,10, 11].
5. Protects your Brain
In addition to keeping your heart healthy and fighting off disease, some studies have indicated that IF protects the health of your brain and may also help slow the progression of neurodegenerative disorders like Alzheimer’s disease. 
In animal studies, the brain and body perform better during fasting. In the case of the brain, cognitive function, learning, memory, and alertness are all increased by fasting. Another animal study found that intermittent fasting protects the brains of mice by influencing certain proteins involved in brain aging. [13, 14]
6. Physiological and Psychological Resiliency
On the top of all the physiological benefits, there is something incredibly powerful about taking control of your hunger, and not having to act on your cravings. IF can gently guide you towards a more resilient relationship with food. It empowers you to make better decisions as well as to get to know your behaviours and attachments around food that you might not have been aware before.
Studies also indicate that IF constitutes a challenge to the brain. The brain reacts to this challenge by adapting response pathways to help it cope with stress, this will in turn have an effect on how our body responds to both psychical and mental stress.
Please note that this is not true for everyone. People who struggle with eating disorders such as binge eating, IF can reinforce the patterns (see below in ‘Things to Consider’ section).
How does it work?
There are a variety of approaches to intermittent fasting, there’s not just one correct method for how to fast.The most traditional ones are:
- 16/8 Fasting– In this method, you fast for 14-16 hours, and restrict your daily “eating window” to 8-10 hours. Within the eating window, you can fit in 2, 3 or more (healthy) meals. Doing this method of fasting can actually be very simple. For example, if you finish your last meal at 6 pm and then don’t eat until 10 the next day, then you are technically fasting for 16 hours between meals.
- 24 Hours Fasting– In this method, you pick one or two days out of the week in which you fast for 24 hours, then eat nothing from dinner one day until dinner the next day. On the other days, you should have normal food intake.
I personally really like the 16/8 Fasting as it is not so hard to follow and it feels like a natural thing to do and my body can easily adapt to it.
Is it for me? How do I Start?
As with anything when it comes to Nutrition, there is not a ‘one size fits all’. We all need to find out for ourselves what works best and what phase physically and mentally we are currently going through. That is why it is really important to consider consulting with a Dietitian, this will give you a good support in the beginning. Specially if this is something really new for you, it is important to keep an eye out to low calorie, vitamin and minerals intake.
If you want to give it a try, go slow on yourself…
If you have never done anything like this before, I would recommend you to go really slowly… your body is incredibly smart and adaptable, although the metabolic changes can take some time to happen. Here are my tips to get you going in a slow and progressive way:
- Start by decreasing the intake of overall carbohydrates (cut off refined ones completely) and increase the amount of fats during the day.
- Increase the gap between your meals. If you are used to eating every 2-3 hours, try not eating for 3-4 hours.
- Consider starting out with a 12-hour fasting first, this can bring you many benefits and will naturally lead you to the 16/8 without much struggle.
Hunger should not be present during those steps. If it is, consider reviewing where changes need to be made.
Important things to consider:
However, it is highly important to consider the potential side effects of regular fasting for certain people or in specific circumstances:
- People with eating disorders may end up binge eating more after fasting.
- Fasting and exercising at the same time may lead to low blood sugar (hypoglycemia). Ths is certainly not true for everyone. So listen to your body and adapt accordingly.
- Fasting by people taking diabetes medications can lead to severe hypoglycemia and can lead to serious health issues.
 Fasting, circadian rhythms, and time restricted feeding in healthy lifespan. National Center for Biotechnology Information, 2014.
 Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.National Center for Biotechnology Information, 2014.
 Effects of intermittent fasting on health markers in those with type 2 diabetes: A pilot study.National Center for Biotechnology Information, 2017.
Effects of Ramadan fasting on glucose homeostasis and adiponectin levels in healthy adult males. Journal of Diabetes and Metabolic Disorders, 2015.
Impact of intermittent fasting on health and disease processes.National Center for Biotechnology Information, 2016.
Favorable changes in lipid profile: the effects of fasting after Ramadan. National Center for Biotechnology Information, 2012.
The growing realization that chronic inflammation is crucial in many diseases opens new avenues for treatment.National Center for Biotechnology Information, 2012.
 Frequency and Circadian Timing of Eating May Influence Biomarkers of Inflammation and Insulin Resistance Associated with Breast Cancer Risk. National Center for Biotechnology Information, 2015.
 Practicality of Intermittent Fasting in Humans and its Effect on Oxidative Stress and Genes Related to Aging and Metabolism.National Center for Biotechnology Information, 2015.
 Inflammation and Alzheimer’s disease. National Center for Biotechnology Information, 2000.
 Chronic intermittent fasting improves cognitive functions and brain structures in mice.National Center for Biotechnology Information, 2013.
 Neuroprotective role of intermittent fasting in senescence-accelerated mice P8 (SAMP8).National Center for Biotechnology Information, 2010.