Intermittent Fasting: What Is It And Does It Make You Fitter?

‘Intermittent fasting’ has been a buzz phrase in the fitness world in recent years. But what is it? And can it actually help you get fitter, or is it just another fad? We’re going to walk through some of the science behind IF and how you can get started in a healthy and safe way.

What Is Intermittent Fasting?

One of the most important things to realise about intermittent fasting is that it is not a singular diet or fitness plan, but rather a broad term for pretty much any diet that cycles through periods of eating and periods of not eating (fasting). Unlike traditional diets, it doesn’t tell you what you should eat, but rather when. It has become extremely popular in recent years and there are many different ways to start your IF journey – which we’ll go through further down!

Is Fasting Healthy?

Let’s start with one of the most important questions: is fasting safe and good for you? When we fast, our bodies experience all kinds of changes. Proponents of IF say this includes an immune response that fixes cells and produces ‘positive metabolic changes (reduction in triglycerides, LDL cholesterol, blood pressure, weight, fat mass, blood glucose),’ according to the Harvard School of Public Health. And research seems to back this up, with ‘a systematic review of 40 studies [finding] that intermittent fasting was effective for weight loss, with a typical loss of 7–11 pounds [3–5 kilograms] over 10 weeks.’

There have been concerns that by significantly reducing calorie intake on certain days, people will compensate during their ‘eat periods’, but studies have shown this to be untrue. However, some people simply shouldn’t go down the route of IF for health reasons, such as those with diabetes or a history of eating disorders.

Weight loss is just one of the benefits of restricting calorie intake through IF.

How Do I Start Intermittent Fasting?

Before you jump straight into intermittent fasting, it’s important to ask ‘How long should I fast for?’ and decide which cycle you want to follow, considering the practical ways to make this happen. First, let’s talk about some of the most popular 24-hour splits.

The 16:8 Method

Possibly the most popular method of IF due its simplicity and the ease with which you can slot it into your daily routine. It involves restricting your eating period to eight hours and fasting for the remaining 16. Many people achieve this by skipping breakfast and eating from about 12 to 8pm or similar.

The 5:2 Method

This very well-known method of IF doesn’t actually involve any periods when you eat nothing, but rather five days of eating normally and two days when you restrict your calorie intake to between 500 and 600 per day.

Eat-Stop-Eat

People following this type of IF commit to either one or two 24-hour fasts during the week. This is usually done from one meal to the same meal the following day. For example, if you finish your evening meal at 6pm, you don’t eat anything until 6pm the following day. People can find starting with a 24-hour fast very difficult, so you can ease your way in with shorter periods.

The 14:10 Method

This regime is similar in structure to the 16:8 method, but affords a longer eating period. You can eat during a 10-hour window, which can mean breakfast at 8am and finishing up dinner by 6pm – not an unusual pattern for many countries, but it does stop that late-night snacking.

The 18:6 Method

This is flipping the 14:10 the other way, by reducing your eating period even more than the 16:8 method and increasing your fasting period. With such a small window, you can only take in calories between say 11am and 5pm, which could make this a harder routine to stick to for newcomers.

The Monk Fast

This style of fast starts to drift away from modern IF diets and more towards classic fasting for spiritual or religious reasons (hence the name). The Monk Fast involves a continuous 36-hour water fast, whereby you take in no calories, but are expected to drink plenty of water. This can be achieved by finishing day one with dinner, not eating at all on day two and then breaking your fast on day three.

Managing Your Fast

Getting through periods of fasting, whether 14 hours, 18 hours or 36 hours, can be hard, but there are ways to manage it. What is and isn’t ‘allowed’ depends on who you ask, but fasting is a personal routine, so do what feels right to you. Proponents of IF recommend drinking plenty of water, as well as hot water and nearly-zero-calorie drinks such as tea. Additionally, many people combine fasting and exercise efficiently by using exercise to distract themselves from the hunger, which can boost the effects of a fast and certainly help with weight loss. However, it is important to consider how you will replenish your energy after a workout, so schedule it to fit in with your routine.

You can use near-zero drinks like tea to get through your fasting periods (just don’t add sugar!)

To stay safe, don’t start with really long fasts. This means avoiding starting with a two-day version of the Eat-Stop-Eat fast and certainly not jumping straight into a Monk Fast. Start out slow and see how your body reacts. And of course, if you experience adverse effects you should take a break and consult a medical professional.

Is Intermittent Fasting Just Another Fad?

Although it has recently boomed in popularity, fasting is nothing new. In fact, humans have evolved to be able to keep going for very long periods without much (or any) food, since it was necessary back in the days of hunter-gatherers and practised for spiritual, religious and health reasons for many hundreds of years. Nowadays, it is endorsed by plenty of health-conscious public figures such as Nicole Kidman, who follows the 16:8 routine, Benedict Cumberbatch, who stuck to the 5:2 principle, and Hugh Jackman, who also goes with the 16:8 model. In fact, Jackman has was an early adopter of IF and an outspoken proponent, and will no doubt be sticking to his rigid regime while passing through Melbourne on his ‘The Man The Music The Show’ tour.

Intermittent fasting isn’t for everyone, but the range of different styles and methods means that if you do want to give it a go, then there is probably a pattern that suits you. It has been practised throughout history and has considerable anecdotal and scientific evidence for the benefits it can have on your health. Start slow and stay safe, and intermittent fasting could become an important part of your fitness regime.