The Ultimate Guide to Intermittent Fasting

Imagine a way of eating that is versatile, does not feel like a strict diet, still allows you to eat your favourite foods, helps you lose weight, and even offers scientifically proven health benefits.
Sound too good to be true? Welcome to intermittent fasting!

This method of eating (notice it is not called a “diet”) is taking over as one of the most popular new ways of losing weight and staying healthy.

What Is Intermittent Fasting?

Intermittent fasting involves switching between specified periods of eating and fasting. It is more about when you eat rather than what you eat.
Since you are technically fasting anytime you are not eating, you have already practised intermittent fasting without even knowing it! Consider the term “breakfast” which flat out refers to breaking a fast.
While it has been around since ancient times, intermittent fasting has become an especially popular method of eating within the last several years.

How Does Intermittent Fasting Work?

At its basic level, intermittent fasting can help the body to use its stored energy (a.k.a. fat).

When we eat, any excess calories (food energy) are stored away for later use. Insulin is a key hormone in the process of storing food energy.

When we eat, insulin rises to help store any excess energy in two ways:

  • Carbohydrates are broken down into individual units of glucose, linked into long chains to form glycogen, and stored in the liver or muscle.
  • Once carbohydrate storage, which is limited, is reached, the liver turns excess glucose to fat. This process of forming new fat is known as de-novo lipogenesis.
  • There is virtually no limit to the amount of new fat that can be created.

The food energy storage process does the opposite when we do not consume calories and the body starts to break down glycogen into glucose to fuel the body. After the body uses up the glycogen, it switches over to using fat as its main source of fuel.

At any time, our body is either fasted or fed. In the fed state we are storing energy and in the fasted state we are burning energy.

Eating from the minute you wake up until you go to sleep means the body is almost constantly in a fed state. Over time, this may promote weight gain as the body does not have enough time to burn stored food energy.

To lose weight, it may be as simple as increasing the amount of time the body has to spend burning food energy and limiting the time spent storing energy. This concept is the foundation of intermittent fasting.

How Does Intermittent Fasting Work?

Isagenix IsaLean Shake

What Are the Different Types of Intermittent Fasting?

The periods of eating and fasting vary depending on which style of intermittent fasting you choose to follow. The beauty of intermittent fasting is the flexibility it offers and the ability to customise it to your lifestyle and needs.

You can fast as long or short as you like (although longer fasts need to be medically supervised).

Here is a quick breakdown of some of the most popular intermittent fasting methods:

The 16:8 Method

This form of intermittent fasting involves a daily 16 hour period of fasting and an 8-hour period (sometimes called a ‘window’) of eating. All meals and snacks are eaten within the 8-hour window, with the remaining 16 hours devoted to fasting.

For example, all meals eaten between 10 am and 6 pm would fit into this method. The timing can be customised based on your lifestyle. Perhaps your mornings are busy and you never have time for breakfast anyway. This would make 11 am or noon a great start to your eating window. The window can also be shifted from day to day, based on your schedule and what works best.

The 16:8 method is generally followed on a daily basis, or almost daily, and truly is a lifestyle.

The 14:10 Method

The 14:10 method is similar to the 16:8 method, although not as well known. As the name implies, the fasting window is 14 hours and the eating window is 10 hours. Some studies show that fasting for as little as 14 hours can provide benefits.

The 14:10 method can be a great option for individuals looking to get started with intermittent fasting. Eventually, you can work up from 14-hour fasts to 16-hour fasts, if desired.

An example eating period would be 8 am to 6 pm, allowing for breakfast, lunch, snacks, and dinner.

The 20:4 Method

This method of intermittent fasting involves a 4 hour eating period paired with 20 hours of fasting. For example, you might eat between 1 pm and 5 pm every day and fast for the remaining 20 hours. This would involve eating either one large meal and a snack or a couple of smaller meals within this time frame.

24 Hour Fasts

24-hour fasts are just as they sound — fasting for an entire 24 hour period.

For example, if you eat lunch on day 1, you would skip dinner that night and breakfast the following day before having lunch on day 2. This method is also referred to as OMAD (one meal a day). Generally, this method is done two to three days a week.

36 Hour Fasts

36-hour fasts involve more than an entire day of fasting. For example, after eating dinner on day 1, you would fast the rest of the day and all through day 2, not eating again until breakfast for day 3.

5:2 Fasting

This is one of the most popular versions of intermittent fasting, consisting of five regular days of eating and two consecutive fasting days. Although they are referred to as ‘fasting days’, you are actually allowed to consume up to 500 calories on these days. The 500 calories can be consumed throughout the day or during one meal.

Nutritional cleansing with Isagenix is based on the science and proven benefits of the 5:2 fasting method.

In nutritional cleansing with Isagenix, the two fasting days are referred to as “Cleanse Days” and involve consuming nutrient-dense shakes and cleanse day approved snacks.

Another intermittent fasting approach related to the 5:2 method is to have “fasting” days (with 500 calories allowed) every other day rather than twice a week.

What Are the Benefits of Intermittent Fasting?

If done right, intermittent fasting may provide health benefits such as:

  • Weight loss
  • Increased fat burning
  • Increased energy
  • Increased mental clarity
  • Possible activation of cellular autophagy
  • Possible reduction in inflammation

In addition to the potential health benefits of intermittent fasting, it offers many unique lifestyle advantages compared to other ways of eating or trendy diets:

  • It saves time (think about all the time normally spent on preparing meals, planning snacks, eating, etc.)
  • There is nothing special to buy to start it
  • It can be done anywhere
  • It is a lifestyle change, not a diet
  • It simplifies life
  • It allows for social eating (for example, if you know you are going out for dinner with friends, you can customise your plan to make sure dinner falls within your eating window)
  • It is flexible
  • It does not require the avoidance of certain foods or entire food groups

Frequently Asked Questions About Intermittent Fasting

While intermittent fasting has various proven benefits, it is always crucial to discuss any lifestyle, medication, or diet changes with your doctor.

Intermittent fasting is not recommended for:

  • Women who are pregnant or breastfeeding
  • People under the age of 18
  • Individuals who are underweight
  • Individuals with eating disorders
  • Individuals with serious medical conditions such as heart, liver, or kidney disease
  • Individuals with type 1 or 2 diabetes, taking prescription medication, or with high uric acid may need medical supervision to fast

Yes. You can continue your usual activities, including exercise. However, eating prior to exercising may improve performance, especially for long-duration aerobic exercise.

It is also crucial to remember to consume enough fluids and replenish sodium if you exercise while fasting.

There are some potential risks and side effects involved with extended fasts (periods of fasting more than 24 hours):

  • Hunger (possibly the most common side effect)
  • Constipation (less food going in means less waste coming out)
  • Heartburn
  • Headaches (these tend to disappear after the few times fasting)
  • Dizziness
  • Muscle cramps
  • Refeeding syndrome (a rare side effect that tends to only happen with extended fasts of 5 to 10 days or longer)

 Since the majority of these side effects are manageable and minor, they do not mean you must stop your fast. However, if you feel truly worried or sick, experience excessive dizziness, feel extremely weak, or experience other severe symptoms, you should stop your fast.

 Just remember to go slowly when you break a fast, prioritise fluids, listen to your body, and consume some salt (bone broth is excellent for this as it contains a host of other nourishing nutrients). Of course, if the side effects persist, contact your doctor immediately.

Fortunately, severe side effects of intermittent fasting are rare, especially if you make a point to supplement with electrolytes and remain adequately hydrated. The biggest rule of starting intermittent fasting -- especially extended fasts -- is always checking with your health care provider first.

With hunger, it can be helpful to remember that it will not continue to build and build until it is intolerable. Rather, it will build and pass, like a wave. If you try ignoring it and drink a cup of tea or black coffee, it should pass. During extended fasts, you may find yourself hungrier on the second day. After that, it gradually decreases. Many people report almost no sensation of hunger by day 3 or 4.

Whether fasting burns muscle depends on the individual and the extent of the fast. During fasting, the body breaks glycogen into glucose to use as energy. After that, fat is broken down to be used as energy.

Excess amino acids also get used for energy. The body does not use its own muscle as fuel unless it has to.

However, some studies suggest that leaner individuals may be at an increased risk of the loss of lean muscle mass.

No. Fasting is not the same as starvation. Fasting is the voluntary, controlled avoidance of food for health, spiritual, or other reasons.

Yes. Here are six quick tips for getting started with intermittent fasting:

  • Drink enough water
  • Stay busy and distracted
  • Drink tea or plain black coffee as needed
  • Ride out the hunger waves and remind yourself they will pass
  • Try different methods to figure out which fits your lifestyle best (the 16:8 method, 14:10 method, or 5:2 method are great for testing out whether intermittent fasting is right for you)
  • Do not binge after a fasting window
Gently. The general rule is the longer the fast, the gentler you must be when breaking it. Eating too much after a fasting window can result in a stomach ache. Although this is not serious, it can be uncomfortable.

Not necessarily. Skipping a morning meal gives the body more time to burn fat for energy. Also, since hunger is lowest in the morning, you may find it easier to skip eating then and move your eating window to later in the day.

However, if you adore breakfast and feel better when you eat it, you can customise your eating window to include breakfast.

Yes. However, women who are pregnant, breastfeeding, or underweight should not fast. Women who are trying to conceive should be aware that intermittent fasting may affect their menstrual cycle.
Not necessarily. Fasting focuses on when and how long you eat whereas calorie reduction focuses more on what and how much to eat.
Most likely. It is possible to consume too much during fasting windows and gain weight or maintain your current weight. However, studies show that people tend to consume fewer calories overall during fasting.
If you are wondering how to get started with intermittent fasting, here is a simple way to begin:
  • Decide which type of intermittent fasting you want to do
  • Start your fasting period, listening closely to your body and stopping if needed
  • Continue your usual activities, trying to stay busy
  • Gently break your fast with a healthy meal or high-quality meal replacement shake
  • Repeat and start enjoying the benefits of intermittent fasting!

Want To Learn More About Intermittent Fasting, Losing Weight, and Getting Healthier?

If you are curious to learn more about intermittent fasting or nutritional cleansing with Isagenix, please feel free to browse our blog or contact us.

Since 2014, we have greatly enjoyed helping our customers achieve their health and wellness goals through the use of Isagenix’s exceptional products and we would be honoured to get you started on your nutritional cleansing journey.