Fasting has been practiced for thousands of years for religious and medical purposes. Its methods and ways have stood the test of time and achieve amazing benefits including increased fat metabolism and weight loss.

People may ask, “But, isn’t that starving yourself?” No, not at all. Fasting is different. Starvation is when you are involuntarily deprived of food for an ongoing time period whereas, with fasting, you voluntary decide not to take in food, be it for health or for spiritual reasons.

Fasting is not “dieting” in the conventional methods. You could more describe it as an eating pattern. When you really get down to thinking about fasting, you have to realize that it came about because the ancient people did not have grocery stores to buy food or refrigerators to store food. Often they had to function without food for extended periods of time.

How does intermittent fasting work

At the very foundation, fasting is about your body burning off excess body fat. If you have body fat, you have food energy that is in storage and when you don’t eat, your body starts to ‘eat’ at the fat to get the energy it needs. Because our lives are all about balance, the same applies to our bodies – eating and fasting keep the balance.

When we ingest more food than can immediately be used for energy, that energy gets stored as fat, to be used later. The key hormone in our body for the storage of food energy is insulin. As you eat food and increase the insulin levels in your body, so you store sugar which is converted to fat. This fat is often stored in your liver but can also be sent to other fat-depositing places of your body. We have two storage systems in the body for energy – glycogen and body fat. When you don’t eat, the above process goes into reverse, so instead of insulin levels rising, they now fall, telling the body to start burning up the stored energy.

Our bodies are constantly in two states, the fed state, and the fasted state – either storing food for energy or burning it. If each of us were to start eating food the minute we got out of bed in the morning, continuing to eat until we went to bed again at night, our bodies would spend all the time in that fed state. We would gain weight, not having allowed our bodies to burn any of that food into energy. To restore some balance and to lose weight, we need to spend that time exercising or fasting because these allow the body to use up that stored energy. Our bodies were designed to work like that. Look at dogs, cats, wild animals; that is what they do. If we constantly eat as sometimes it is recommended, our bodies aren’t going to get around to burning the body fat, instead; it will just store it.

Types of intermittent fasting windows

There are short fasts that last up to about 24 hours and then there are the longer fasts that last well over 24 hours. Those who go on the shorter fasts do them more frequently than if they went on a long fast. Most intermittent fasting plans don’t tell you what to eat; they rather tell you when to eat, making them very customizable.

The 8-hour eating window or 16:8 fast

This is where you eat all your meals within 8 hours. The remaining 16 hours of the day you fast. This is usually done on a daily basis. It is basically eating all of the meals in an 8-hour window.

The 20:4 fast

This is where you eat your meals within a 4 hour period, leaving the other 20 hours to fast.

The 24 hour fast

This involves fasting from lunch on one day to lunch to the next day, or from supper to supper. If for instance, you eat your lunch today, you skip your dinner and also your breakfast the next day, eating only again at lunchtime. When you eat only once in a day, it equates to eating around 3 times a week.

The 5:2 fast

On this diet, you eat regularly for 5 days in a row, and then you fast for 2 days. On the 2 fasting days, you are ‘allowed’ to eat up to 500 calories on each of the days, any time and spread out or eaten in one meal. This fasting method was made popular by Dr. Mosley in his book called ‘The Fast Diet’.

The 36 hour fast

Look at it this way – you eat your dinner on the first day, on your second day you fast and on the third day, you eat breakfast. That makes 36 hours of fasting.

Some people shouldn’t fast for the following reasons:

  • If you are underweight and you’re BMI (body mass index) is under 18.5.
  • If you are pregnant – because your baby needs all the nutrients it can get and also if you are breastfeeding.
  • If you are under 18 because you need the nutrients for growing.

For those who long to fast but you have the following conditions, you would need to be under supervision from your doctor in these instances:

  • If you have types 1 & 2 diabetes mellitus
  • If you are using prescription medicines
  • If you have high uric acid in your body or suffer from gout. If you don’t get the necessary nutrients you could experience fatigue, constipation, dizziness and a hike in your uric acid levels

Want to give fasting a try? Here are some tips to help along the way:

  • Drink plenty of water
  • Stay busy so you are not concentrating on your fasting as much
  • Drink coffee or tea to help you ride out the pangs of hunger
  • In-between fasting periods, following a low carb diet can reduce your hunger and make the whole fasting process easier.
  • Remember – don’t binge after fasting! The way to break a fast is to start off gently. The longer you were on the fast, the more gently you need to introduce foods to your body.

Is reducing calories the same as fasting?

No. Fasting is reducing the time you eat and calorie reduction is deciding what to eat and when. They are really two different decisions and issues, not to be confused. Yes, sure, fasting does reduce calorie intake but it has benefits to your body that reducing calories does not offer.

How do I get started fasting?

Decide which type of fast will work for you then start.

  • If you aren’t feeling well on the day you start, or you have any medical concerns, you should seek help and advice from your medical doctor.
  • You may also continue with your usual way of life while fasting; it is best to keep busy
  • Remember when you to break your fast, do it gently
  • There are several apps to help you monitor your fasting periods.

It’s that simple. The LEVL device can help you understand the impact of your fast on your fat metabolism.


This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.