What is Intermittent Fasting & How Does it Work?

Whether because we have made a New Year’s resolution, or as a result of overindulgence during the festive period – or, in many cases, a little of both – January is the time when diets become part of most people’s vocabulary. With a clean slate, we can look towards the coming twelve months with clear goals in mind – and one of those goals, for many people, is to lose some weight.

Part of the process, of course, involves getting back in the gym. Any balanced plan to get fit needs to involve exercise – but what we intend to look at right now is the other side of the equation – the one that involves what you are putting on your plate, how much of it you are serving up, and how often you are eating. More specifically, we are going to look at the question of fasting. It may be hard to countenance after the most indulgent month of the year, but could food abstinence be the key to a healthy new year?

What is fasting?

Right off the bat, this might seem like a simple question: fasting is abstaining from food, isn’t it? And yes, that is the simple answer, but from a health standpoint there are many different ways you can fast. After all, you can’t just never eat again – so if you’re considering a fasting diet, you’ll need to know the ins and outs of how they work – and the ways in which they can fail. The most in-vogue way, and among the most effective, is intermittent fasting.

Okay then, what is intermittent fasting?

Intermittent fasting is a weight-loss process that involves controlling when you eat more than what you eat. The idea behind intermittent fasting is that, after a certain period of time, your body will move from getting energy from the foods that you have eaten to taking it from bodily reserves, primarily from fat stores. As a result, you can find that your body will demand food less often and that you will lose fat, therefore becoming healthier.

Does this mean that you can eat whatever you want when you do eat? No, not really – it is not a good idea to eat sugary snacks or many carbs, as these take longer to digest and your body will have to work harder to fully process them. This means it spends less time burning fat, and in effect your body will stay hungry for longer. One major advantage of intermittent fasting is that, once you are used to the process, you will find hunger is less common.

How long should I fast for?

This is a question that divides adherents of intermittent fasting. There are a few different schools of thought, with the most prominent being 16:8 fasters. Within a 24-hour period, these fasters will have an eight-hour window in which they can eat – usually between 1 – 9 PM or similar. What this means in practice is that such people simply skip breakfast, and do not eat snacks after dinner. For more pronounced results, you can change the numbers to be 18:6 – where your eating window is six hours in total – or even 20:4.

Another approach – which has been publicised for years as the 5:2 diet – is to eat normally on five days of the week and eat just 500-600 calories on two (non-consecutive) days. The thinking behind this approach is that the “normal” days keep your metabolism at its strongest, ensuring maximal benefits from the low-calorie days.

A more extreme approach, known as OMAD (One Meal A Day) involves fasting for the vast majority of the day, and eating just one meal – which should be substantial and nutritionally-balanced. This is a difficult diet to follow, and it is not recommended as a long-term endeavour – it is exceptionally hard to get all the nutrients you need in a single sitting, and over a long period the diet can see you losing not just weight but also experiencing muscle breakdown. You may well also experience severe fatigue and lack of energy, among other concerning symptoms.

Which of these is the best approach?

In many ways, it depends what you are seeking to achieve – and a lot depends on you more generally. The same approach can work differently for different people, because we all need different things depending on our lifestyle, gender and general health among other factors. If you are going to try fasting, it is always advisable that you start with a simple 16:8 pattern. You can achieve better results if, instead of a carb-heavy lunch, you swap in low calorie shakes which allow you to keep cravings at bay and get beneficial nutrients at the same time.

It should also be recommended that, before embarking on any diet, you speak to a doctor regarding your choice, as they will be best positioned to advise you on how a diet may affect you in light of any long-term health issues. It cannot be stressed enough that what works for one person may not work the same way for another, and persisting with a diet that isn’t working for you is only likely to have negative repercussions for your health.

What about my overall health?

It is worth bearing in mind that your weight is one part of the picture that makes up your general health. You may want to lose weight because you want to wear certain clothes, or look great in selfies, but the primary motivation behind any diet plan should be to ensure you are healthier going forward. It is, therefore, essential to keep in mind that your diet needs to offer global health benefits – which is one major reason why, even when fasting for most of the day, you should be making sure the meals you do eat are balanced.

One piece of good news is that, when you fast, your body increases its production of Human Growth Hormone (HGH). Not only does this encourage muscle growth, it also burns fat. As long as you are getting the nutrients you need, the production of HGH is hugely beneficial for general health. Fasting is also beneficial for the body’s treatment of insulin, improving physical sensitivity to insulin and lowering its levels in the body. This, again, helps burn fat stores and regulates insulin production (although, for this specific reason, it is essential to speak to a doctor before fasting if you have, or suspect you might have, diabetes).

Fasting also encourages cellular repair processes including autophagy, in which your body seeks out and removes old, dysfunctional cells. Among other benefits of these processes, you will find that you are less prone to inflammation and infections. Evidence also suggests that your immune system will be boosted, and autophagy in particular is one of the body’s defence mechanisms against cancer.

Does intermittent fasting have anything to do with the Ketogenic diet?

The two things are related, but not indivisible – you can fast without getting on “keto”, which is a diet that is marked by being high in fat, low in carbohydrates and high in protein. However, to get the best results from a Ketogenic diet, it is vital to include intermittent fasting, as this will help you reach the stage of ketosis. Ketosis is essential for burning fat, reducing hunger and allowing your blood sugar to stabilise.

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Is there anything else I should know?

Intermittent fasting is, in and of itself, a safe and trusted method of losing weight as long as it is done in a balanced way. However, it goes without saying that you need to keep a close eye on the results of any weight-loss process not just on the scales, but in terms of your overall health. If you start to experience headaches, loss of energy, nausea or impairment to your mental well-being, it may be that you need to change things. 

Many dieters hear about the health benefits of a certain food, or a way of eating, and believe they have found the silver bullet that will deliver them perfect health and simple weight loss, and these people always forget the key phrase:

“As part of a balanced diet.”

The beneficial nutrients that you’ll see mentioned on food packaging are more than just selling points. Protein and fibre add balance and are especially essential to your physical health when fasting, and the more vitamins and minerals you can get through your diet, the better. You should also benefit from supplements. Vitamins D and complex B are hard to get from food, and magnesium is useful for muscle health, so these are a good place to start. For maximum benefit, it is advised that you take supplements with food, as this ensures better absorption.

As long as you take the necessary precautions as explained above, and only take major diet decisions in consultation with your doctor, intermittent fasting can be hugely beneficial for you. Make sure not to get too carried away, and you could see health benefits that go well beyond weight loss.

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