Intermittent Fasting 101: The Beginner’s Guide

by | May 11, 2019 | Digestive Health, Health Articles

What is intermittent fasting? How do you do it? What are the benefits? Who shouldn’t do it? We’re covering it all in today’s post on intermittent fasting 101, the beginner’s guide!

Ever wondered what the deal is with intermittent fasting? It’s grown rapidly in popularity over the past few years among health enthusiasts and researchers alike. In fact, there are countless studies that illustrate its many benefits.

The concept of voluntary fasting is nothing new and has been around for ages in nearly every culture and religion. And when we consider human evolution, well, periods of “fasting” have also most certainly existed.

I first discovered intermittent fasting a couple years ago as a way to support my digestion and it’s definitely been a piece of my gut-healing journey. So let’s dive in! What is it, what’s it good for, and who’s it not suitable for?

Watch the video below or continue reading. You can subscribe to my YouTube channel for weekly wellness videos:

What Is Intermittent Fasting?

Intermittest fasting is kind of an umbrella term that includes a few different fasting strategies. The idea isn’t so much about what you eat, but when you eat. That is, you’re eating the same amount of food that you usually do but during a shorter period of time in the day.

Fasting refers to any period of time when you are not eating food. Everybody actually fasts each night – it’s called sleeping!

But why does it matter when we eat? Well, here’s why. Nowadays, we 24/7 access to grocery stores, we have lighting that enables us to stay up as late as we’d like, and not surprisingly, most people get into the habit eating constantly all around the clock, or eating really late at night. This creates wonky blood sugar patterns, appetite irregularities, and it can negatively impact our sleep. Among a bajillion other things.

Our bodies are actually designed and very well equipped to handle periods of fasting. In fact, it’s far more natural for us to do a bit of fasting than it is to eat copious amounts of food at all hours of the day. Fasting is beneficial – that’s why people do it! But it can come with some risks for certain people, so read on.

Types of Fasting Methods

Time-Restricted Eating: This eating style is based off of the science of circadian rhythms. It’s my favourite because it’s simple and logical in nature: eat during the day, stop eating at night. This is a very natural rhythm for our bodies to align with.

With TRE you generally want to focus on an eating window of 10-12 hours and a fasting window of 12-14 hours.

16:8 / 18:6: These are a couple different options for lengthier fasts that involve fasting for 16 – 18 hours, and eating over a span of 6-8 hours. An example of these would be eating a very early dinner and fasting until morning, or eating dinner at a regular hour and fasting until lunch the next day.

It’s generally not recommended to do overnight fasts longer than 14 hours each day for women. Once or twice a week may be fine for some people, but female hormones are easily disrupted if extended fasts are done daily. Instead, 12-13 hours is ideal!

5:2 or Eat-Stop-Eat: This type of intermittent fasting involves eating in your usual manner for 5 days of the week, and either greatly restricting food intake on 2 non-consecutive days (such as Monday and Wednesday), or fasting altogether on those days (two 24 hour fasts). This type of fast is quite restrictive, obviously, and while I haven’t tried it myself, some people like it.

Benefits of Fasting

1. Improved Blood Sugar Balance and Insulin Sensitivity

Intermittent fasting can improve insulin sensitivity. To understand how, here’s a little biochemistry for you:

When we eat, the sugars from our food signal our pancreas to produce insulin to usher it into our cells. Your liver also stores fatty acids in fat cells and converts sugar to something known as glycogen. Once your body has stored all the sugars and fats from your meal and your insulin and blood sugar drops, your pancreas secretes a hormone called glucagon to tell your liver to convert that stored glycogen back into sugar and to release it into our bloodstream to balance out our blood sugar. Fatty acids are also released back into our blood stream for our cells to use as energy!

These ‘storage’ and ‘burning’ modes are supposed to happen cyclically throughout the day, and we allow ourselves to use up remaining stores when we fast sufficiently through the night. But when we’re eating constantly around the clock (coupled with lots of high sugar foods), we disable our ability to transition through these metabolic phases and instead, stay stuck in “storage mode” with too much insulin being secreted all the time. Consequently, this can lead to insulin resistance in some cases, or low blood sugar (hypoglycemia – a sign of insulin resistance).

Do you easily get shaky, weak, or dizzy from not eating for a short period of time? If so, you need to work on improving your blood sugar levels by improving insulin sensitivity. Circadian rhythm timed-eating is one way to help.

So this is why IF is so good for improving insulin resistance, fatty liver, and conditions associated with blood sugar irregularities like PCOS. It’s also why it can aid weight loss, because you allow your body to exit storage mode and burn internal resources instead. Plus, it’s great for regulating appetite by helping to balance hunger and satiety hormones (ghrelin and leptin).

2. Autophagy! (the coolest thing ever)

Autophagy is a pretty cool thing. It’s basically a cellular cleansing process that occurs when our cells have insufficient sugar. It causes them start breaking down their own old, damaged or diseased cell fragments to create new energy and in turn, new, regenerated cells. This occurs more in longer fasts but we’ll experience it to some degree during overnight fasts of 12-13 hours. You don’t want autophagy occuring all of the time, otherwise that’s starvation, but a little bit each night is great.

3. Improves Cognitive Function

Enhances cognitive function and mental clarity. Causes an increase in a molecule known as BDNF (brain-derivated neurotrophic factor) which plays a roles in mood and cognitive function.

4. Supports Cardiovascular Health

Fasting is also great for our cardiovascular system and can even help to reduce reduces cholesterol, specifically LDL (the bad kind).

5. Better Gut Health

One of my favourite things about intermittent fasting, and why I began exploring it nearly two years ago, is because of how it can benefit our digestion and overall gut health. It’s particularly good for our microbiome and is a great way to give our digestive organs a break from constantly working throughout the day. Plus, fasting can help lower inflammation which means less disease, better immune function, and a healthier whole body.

Circadian-rhythm based eating is one of the many topics we discuss for how to reset our gut in my Digestive Reset Program. You can learn more below:

Who Should Avoid Fasting?

Everybody has a fasting window at some point during their day. But when it comes to extended fasts (14 hours or more), here’s who should avoid them:

  • Pregnant or breastfeeding mamas
  • Those looking to get pregnant (your body will see frequent, lengthy fasts as a period of famine). Circadian rhythm-timed eating, however, can improve fertility.
  • Those dealing with extreme stress (extended fasts are stressful on the body)
  • Diabetics. Speak to your doctor about fasting.
  • Those with a history of eating disorders. Always speak to your doctor prior to exploring any kind of fast on your own.

I’ve been experimenting with intermittent fasting in my own life for a couple of years now, and I respond really well to it. I’ve personally followed eating patterns such as 11am-7pm, and I especially love the circadian-rhythm based Time-Restricted Eating. It’s such a wonderful feeling to eat in alignment with day and night. An app I recommend is Zero that allows you to track your fasting/eating windows and set timers for specific fasting methods.

While I’ve never done a 24 hour fast (or longer), I’d like to try it sometime! What about you? Have you ever tried intermittent fasting? Share your experiences below, or leave any questions!

by Meghan Livingstone

Note: this post may contain affiliate links. Learn more here.

You might also like…

7 Ways to Improve Gut Health

7 Ways to Improve Gut Health

Improving our gut health is one of the best things we can do for our overall health. In today's post, we're exploring 7 ways to improve your gut health, including some simple things that you can implement right away. When it comes to improving our gut health, there...

What is Food Combining + Should You Do It?

What is Food Combining + Should You Do It?

If you're familiar with food combining, you may have wondered if it's beneficial to practice. In this post we're covering what it is, how it works, and if we should do it. There are many diet trends out there. Some that have valid principles, while others not so much....


  1. Allison Halbakken

    Hi Meghan! I’m wondering about intermittent fasting for someone with a Thyroid condition, specifically Hashimoto’s. You had mentioned that it causes stress on the body, which I know is generally to be avoided when you have Hashi. Just curious what your take on this is! Love your content and appreciate you đŸ™‚

    • Meghan

      Hi Allison! Very lengthy fasts and done frequently are what can cause stress on the body, but circadian-rhythm based fasting (and even 16-18 hour fasts once or twice a week) are excellent for health and can actually benefit conditions such as Hashimotos since fasting helps reduce inflammation, reboots immune function (very helpful for autoimmunity), and promotes a healthy gut microbiome. Of course, it’s very important that you take into consideration your unique health status, pay close attention to how you feel, and speak with your doctor if you have any concerns. I hope this helps! xx

  2. Laurie

    Hi Meghan, I did IF For about 3 to 4 months and really enjoyed it and the benefits especially when it came to regulating my appetite. However I have IBS and I struggled so much with gut issues while intermittent fasting. When I stopped I realized that my stomach really needed food in the morning to kickstart my digestion and otherwise I felt cramped and constipated the rest of the day. Do you have any suggestions for how to make it work in a case like this?

    • Meghan

      Hi Laurie! I’d suggest you stick to having breakfast at a time that feels best for you in the morning, and instead focus on an earlier dinner so your fast doesn’t extend far into the next day. đŸ™‚ I’m glad to hear you’ve experienced some of its benefits! Hope this helps!

  3. Sarah

    I have been doing the 16:8 for a while now! I am less than 30 minutes away from completely my first 24 hour fast! I have really enjoyed it and I feel great….though next time I do it, I will pick a different time frame. I did 3pm to 3pm and it is just an awkward time!

    • Meghan

      Hi Sarah! I really want to try a 24 hour fast! It’s on my to-do list haha. And yeah I can imagine the 3pm – 3pm timeframe being a little weird!


Submit a Comment

Your email address will not be published. Required fields are marked *


Hi, I’m Meghan. I’m a Certified Holistic Nutritionist, blogger, and YouTuber with a passion for simple living, digestive wellness, and all things healthy and natural. I’m here to inspire you to create a life you love living.