What are the benefits of fasting?

What are the benefits of fasting? And can you use a fasting diet to lose weight?

11 min read


06 Aug 2019

Craig Harris


When you consider that at any one time 44% of the American population is dieting and that 14% of them have tried fasting for weight loss; it does make you wonder about the benefits. Does it really work? Or is it another fad diet?

In this article we shall explore the benefits of going on a fasting diet and how long can you safely go without eating.

What are the benefits of fasting?

When you think about losing weight, what is the first thing that springs to mind? Cutting out calories, of course! And there is no denying that a fasting diet can help to restrict your calorie intake, as it is based on the principle of abstaining from all or some foods/drinks for a set period of time (usually a 24 hour fast, but some can last as long as 72 hours). But does it actually work?

Well, it depends on the fasting strategy you adopt…

For instance, relying solely on fasting for weight loss won’t help you to reach your goals (in the long term) because once you stop, you’ll more than likely regain this weight. However, if you approach it sensibly and incorporate intermittent fasting (a cycle of fasting and eating) into your weight loss plan, then you can experience success.

Before we get into that particular fasting for weight loss technique; here is a brief overview of the key benefits of fasting:

    • Insulin levels drop – when you fast, this causes the presence of insulin in your blood to fall. As a consequence, your body starts to burn more body fat – enabling you to lose weight – as it forces your body to use your glucose reserves for energy.

The Science: by decreasing insulin resistance – and in turn increasing your body’s sensitivity to insulin – this enables glucose to be transported to your cells more efficiently. This, paired with reduced blood sugar levels, can prevent any unwanted spikes and stop you from suffering from blood sugar crashes.

    • Human growth hormone (HGH) level boosts – would you believe it can increase by up to 5 times its normal levels when you fast for just two days? According to studies, this increased level of HGH is associated with fat burn, muscle gains and weight loss. HGH secretion is also vital for growth, your metabolism and for gains in muscle strength.
    • Cellular repair processes begin – fasting can help encourage cellular repair processes, including removing any waste materials from your system.
    • The body protects against disease – studies suggest fasting may be able to protect you from certain diseases including cancer. In one rat study, adopting alternate fasting helped to block tumor formation. Whilst another test-tube study found that exposing cancer cells to multiple cycles of fasting was as effective as chemotherapy in delaying tumor growth. It can also increase the effectiveness of chemotherapy. NOTE: again a lot of this research has been done on animals and cells, so further studies on humans are required.
    • Reduced blood sugar levels – alongside reducing insulin resistance, short-term intermittent fasting has been found to lower blood sugarand levels in those with Type 2 Diabetes.
    • Fights inflammation – whilst some inflammation is normal when dealing with immune processes; chronic inflammation can contribute towards heart disease, cancer and arthritis. Fasting has been found to reduce inflammation, helping you to remain healthy and fighting fit. In one study of 50 males, intermittent fasting (for 1 month) dramatically lowered inflammation. Participants saw similar benefits when they fasted for 12 hours a day for a month.
    • Improves heart health – through a combination of improving your blood pressure, triglycerides and cholesterol; fasting can enhance the health of your heart. In one study, 8 days of alternate fasting helped to lower bad cholesterol and blood triglycerides levels by 25% and 32% (respectively), whilst in another study of 4,629 people, fasting helped to lower the risk of coronary artery disease and diabetes.
    • Boosts brain function – admittedly research on this topic is still relatively limited. However, what has been found so far (based on animal studies) suggests a fasting diet could be good for your brain health. A study on mice over the course of 11 months saw improved brain function and structure, whilst other animal studies have revealed fasting as a means to improve your brain health; create new nerve cells (helping to enhance cognitive function), and prevent neurodegenerative disorders e.g. Alzheimer’s and Parkinson’s.
    • Assists weight loss – fasting to lose weight is fairly common, and by limiting your calorie intake and boosting your metabolism (through short-term fasting) successful weight loss is possible. This is achieved by increasing the release of neurotransmitter norepinephrine. In doing so, you can see reductions in body weight and fat.

During a review of whole day fasting, researchers found that it could decrease body weight by up to 9% as well as lower body fat (over a 12-24 week period).

  • Delay the signs of aging and extended longevity – multiple animal studies have seen promising results in extended life spans. Rats who fasted every other day experienced delays in aging and lived 83% longer than those who didn’t fast. Similarly, other animal studies have noted improved survival rates and longevity. NOTE: future human research is still needed.

PLEASE NOTE: once you start eating again, your glucose reserves will be restored, meaning you’re likely to regain the weight you’ve lost during your fast.

Is fasting good for you?

Is fasting good for you?

This is a hard one to answer as it depends on which fasting approach you take and how you choose to fast.

For instance, some are more restrictive than others e.g. water fasting (drink only water for a set amount of time) and juice fasting (drink only vegetable or fruit juice for a set period of time). With both of these, there is a risk of you depriving your body of essential nutrients, as they expect you to completely cut out food.

Now, doing a short 12 hour stint with either of these occasionally shouldn’t harm your health. However, if you were to do them for longer than 24 hours, then you would need to speak to a doctor first in order to keep your body safe.

Then of course there are the less restrictive fasting techniques, such as intermittent fasting, partial fasting and calorie restriction. Each of these aims to control your daily calorie intake by cutting out certain foods/drinks for a set period per day before encouraging you to resume your normal diet.

Admittedly, these aren’t as extreme at the first two, and can even be good for you!

Related Article: 800 Calorie Diet Plan

Partial fasting is especially helpful as it asks you to exclude processed foods, animal products and caffeine for set periods of time. Foods that you’d normally avoid during a diet anyway. Perfect!

That being said, fasting is not for everyone. For instance if you have diabetes or low blood sugar, then fasting could trigger spikes/crashes which could be dangerous to your health.

Similarly, if you have any underlying health conditions or are underweight, elderly or are an adolescent; then you should seek out medical advice first (before you decide).

Does fasting for weight loss work?

Like we mentioned earlier, fasting for weight loss does work in theory – as long as you approach it sensibly and don’t do it for too long a period of time.

Yes, it will encourage weight loss (primarily water weight loss) over the duration of your fast; however, the real risk lies in how you behave once your fast is over.

For instance, if you resume the exact same eating habits you followed before the fast, then you’re likely to put the weight you’ve lost straight back on – especially if you have a habit of binging/overeating, or like your junk food.

Yet should you make a conscious decision to eat better (after the fast), then you can minimize the amount of weight put back on.

But that is not all you need to consider. Take the following points:

  • One: it is inevitable that you’ll regain the weight you lost – in the long term – if you adopt a basic fasting diet of just juice and water. Why? Because this kind of dieting is extreme, unhealthy and is so calorie restrictive that your body will enter starvation mode.
  • Two: Alongside entering starvation mode, fasting will also cause your metabolism to drop (further slowing down your body).
  • Three: Whilst you’re fasting your appetite will naturally be curbed, helping you to feel less hungry. YET once you start eating normally again, this suppression will disappear and you’ll end up feeling hungrier than normal. And should you give in to these sudden cravings, weight gain will follow.

How long can you go without eating?

How long can you go without eating?

FACT: We need food and water in order to survive. We can’t live without them!

Yet, it IS possible to go long lengths of time without eating – 3 weeks to be precise (NOTE: this is based on you receiving plenty of water to drink).

Knowing this, it is easy to see where the idea of fasting came from, as we can arguably go days without having anything to eat.

However, like we mentioned before – our bodies require a certain amount of calories each day in order to function. In foods absence, our bodies will begin to enter starvation mode, and will deliberately conserve calories/slow down in order to keep you alive.

Now water is an entirely different story. Which makes sense given that at least 60% of our bodies is made up of water. We NEED to consume water as we can only last so many days without it.

Again, this info helps to support the theory behind certain types of fasting i.e. water fasting and juice fasting, as these liquids give us (temporarily) what we need to survive.

How does intermittent fasting work?

Whilst traditional fasting won’t help you to keep the pounds off; intermittent fasting is a different kettle of fish. And if you’re wondering how to fast the right way, read on.

Unlike old-fashioned fasting that asks you to go without food – often for long periods of time – intermittent fasting differs because it doesn’t change WHAT you eat. It simply changes WHEN you eat.

What does intermittent fasting involve in order to work?

  • You have to skip one meal a day – usually breakfast – to encourage your body to enter into a fasting state. NOTE: this typically occurs 12 hours after your last meal. Once you enter into this state, your body will start to use existing fat stores for energy, leading to weight loss.
  • The two meals you do have should be eaten around 1pm and 8pm to give your body time to enter into a state where it can achieve optimal fat burn (plus other benefits).
  • It can be broken down into subcategories e.g. alternate-day fasting or fasting periods of around 12-36 hours. In this situation, you will either get to eat every other day or you will be given a restricted length of time per day when you can eat (this involves a limited calorie intake which you can have for these few hours).
  • The rest of the day you should eat two healthy, balanced meals.

What are the benefits of intermittent fasting?

Intermittent fasting can do more than just help you to lose weight. It has also been linked to the following benefits:

  • Reduced belly fat – fasting can trigger a combination of reduced insulin, higher HGH and elevated norepinephrines that enable you to break down fat and use it as fuel for your body.
  • Weight loss – this occurs when falling insulin levels (caused from lack of food) encourage your cells to release glucose stores as energy. When this regularly happens, weight loss may follow. This weight loss is further enhanced by the restricted number of calories you’re consuming.
  • Boost your metabolism – instead of slowing it down (like most calorie restrictions).
  • Protect your body from muscle loss – again, something that usually only occurs on calorie controlled diets.
  • Decreased inflammation – providing you with added protection from common conditions caused by inflammation i.e. heart disease and cancer
  • Delays the onset of tumors – animal studies suggest this type of fasting can inhibit the onset of cancerous tumors.
  • Improved heart health – intermittent fasting has been found to reduce blood pressure, heart rate, total and LDL cholesterol, triglycerides and blood sugar levels which can all impact on your heart.
  • Improved brain health – by helping to suppress inflammation in the brain, this can help to keep it healthier, enabling you to learn better and benefit from greater memory retention. Intermittent fasting has also been linked to reductions in neurological disorders including Alzheimer’s, Parkinson’s and strokes.
  • Decreased risk of Type 2 diabetes – by lowering blood glucose and insulin levels, this will not only encourage weight loss but can be used to prevent diabetes.

>> Time Restricted Eating for Weight Loss >>


So is fasting good for you? If it is intermittent fasting, then yes it is. This form of fasting diet limits the amount of nutrients lost from restrictive fasting (i.e. water or juice fasting), and only encourages you to fast at set times of the day and not all day long.

This means if you do it right i.e. safely and as part of a healthy diet and exercise regime; then the benefits of fasting can extend into improved blood sugar levels; heart and brain health; decreased inflammation AND weight loss.

Related Article: 800 Calorie Diet Plan

For safer and longer lasting weight loss though, we recommend sticking with proven supplements such as PhenQ. A quality fat burner and appetite suppressant, PhenQ can help you to successfully move towards healthier eating habits and produce weight loss that lasts.

Craig Harris