I have been wanting to do a post on intermittent fasting for a while now! It's probably one of the things that I get asked about most, and I've had such positive experiences with it, so I'm very excited to be sitting down to write about this topic.
First things first - I want to emphasize that while intermittent fasting (or "IF", as I'll refer to it from here on out) has worked well for me, it's not for everyone. In addition, a disclaimer: this post is purely about me sharing my own experiences with IF. I am not a doctor, nutritionist or dietician - if you have any blood sugar issues, a history of disordered eating, or any other health or medical conditions, please consult with your health care provider before attempting IF.
The history of food and eating
Human beings have actually been fasting to some degree for a very long time - back in the hunter/gatherer days, food was scarce, so people would have to go long periods of time without eating. Naturally, human beings evolved in such a way that they could adapt to this pattern of eating.
In this day and age, it's a different story - food is so readily available that obesity is a huge problem in our country. Food is constantly within our reach, and we've gotten used to consuming it every 2-3 hours, usually within a 12-14 hour time frame. I remember in my early 20s, I would wake up and immediately be starving. Seriously, you could not get food in me fast enough. What I didn't realize is that since I ate every morning around 7am, and stopped eating around 9pm, my hunger hormone ("ghrelin") would send signals to my brain to increase hunger, and get my body ready for food. It was used to eating on this schedule, and didn't know otherwise.
I remember finding it so time consuming to prep a meal and 2-3 snacks to take with me to work or school - it was annoying to lug so much food around, and to be hungry every couple of hours. Since I was pretty active at this time, and had never tried intermittent fasting, I didn't even question it. I remember my manager at work telling me that he was doing IF, and my eyes grew wide with shock as he told me he didn't eat until the early afternoon. "That's SO unhealthy", I thought. All I had ever been told was that skipping breakfast was bad, and that not eating every 2-3 hours would make you gain weight, and leave you feeling sluggish and tired.
Well, fast forward a few years later, when I was in my mid-twenties, and I started to hear more and more about IF. A writer that I followed on Instagram randomly posted about it, and raved about how it helped her be more productive, lose weight, and develop a healthier relationship with food. She also talked about North American diet culture, and how we are constantly thinking about food, portion sizes are increasing, and we panic at the first sign of hunger. It really got me thinking. That same night, I remember Googling IF for several hours. I learned more about what it actually entailed, read about all the health benefits, and saw that it was getting pretty popular within the health and wellness world (which I had just discovered and fallen in love with).
What exactly is IF?
Great question! In simple terms, it's a schedule of eating that many people choose to implement in order to see health benefits, such as weight loss/maintenance, increased mental clarity and cognitive function, and improved digestion and blood sugar stabilization. It's also super convenient, and works well for people who prefer eating a few larger meals, rather than several small meals throughout the day.
There are two main components of IF; your "eating window" and your "fasting window":
Eating window - the time in which you are consuming food and drinks that will cause insulin secretion (insulin is a hormone produced by the pancreas which helps your body use glucose for immediate energy, or store it for future use). Examples of food/drinks that will cause insulin secretion: oatmeal, broccoli, chocolate chip cookies, matcha lattes, green juice, apples, dark chocolate, bread, salad, pizza, carrots - basically any food or beverage that contains calories.
Fasting window - the time in which you are not consuming food; usually, at least half of your fasting window is spent sleeping. During this time, you can only drink water, black coffee/tea, or herbal tea. You can use natural zero calorie sweeteners such as Stevia and Lakanto in moderation, as these have not been shown to cause insulin secretion, but I would keep these to a minimum. I would not recommend using artificial sweeteners (i.e. Splenda, Sweet 'n Low, etc.) at all. If you're not drinking a ton of water during your fasted window, you're doing it wrong!
One thing I do want to emphasize is that IF is not a way to drastically cut your calories. It can be very helpful for those who are trying to lose weight, as you have a shorter eating window, but it's not meant to induce weight loss as a result of starvation. Trust me, I've done the super low calorie thing - it's not sustainable, it's damaging to your metabolism, and has such a negative impact on your ability to enjoy life.
In order to maximize the benefits of IF, I recommend the following:
- drink lots of water during your fasting window
- pay attention to your hunger cues
- use your fasting window to be productive (i.e. run errands, schedule meetings, exercise, get any work done that you can)
- whether you are tracking your macros (aka macronutrients - carbohydrates, protein, and fats) or not, make sure you are consuming enough food during your eating window to sustain yourself during your fasting window (i.e. you should not struggle to get through each fast, and wake up ravenous every morning - this is a sign that you're not consuming enough calories to meet your body's needs, and/or that your blood sugar is unbalanced)
- be flexible - if you need to break your fast a little early or late, that's totally fine!
- do what works for YOU and your schedule, not someone else's
Types of IF
Still with me? Ok, let's move on to different types of intermittent fasting. There are several different IF schedules that you can choose from, with the most popular being the following:
14:10 - this means 14 hours fasted, with a 10 hour eating window
16:8 - this means 16 hours fasted, with an 8 hour eating window
20:4 - this means 20 hours fasted, with a 4 hour eating window
Eat stop eat - this means fasting for 24 hours, 1-2 days per week (I don't think I'd ever even attempt this one lol. Too intense for me!)
The great thing about IF (if it works for you) is that the eating windows are flexible and customizable. For example, if you start work at 7 am, and were using the 16:8 schedule (16 hours fasted, 8 hour eating window), you could eat during whatever time period you prefer, as long as it's within an 8 hour window. For example, you could choose from any of the following eating windows:
10 am - 6 pm (which means fasting from 6 pm - 10 am)
11 am - 7 pm (which means fasting from 7 pm - 11 am)
12 pm - 8 pm (which means fasting from 8 pm - 12 pm)
You get the picture! I started trying out IF in 2015, and quickly fell in love with the 16:8 schedule. In the morning, I would sip on black coffee with stevia, herbal tea, and water for most of the morning, then "break my fast" around noon or 1pm. I would then eat regularly for 8-9 hours, and stop eating around 8 or 9pm that evening. It was quite convenient, and a nice break for my digestion in the morning.
Benefits of IF
There are so many! To keep things concise, I'll list them some of them out in bullet points:
- reduction in blood pressure
- increased insulin sensitivity (your body will be more sensitive to the effects of insulin, which helps with uptake of glucose into your cells, meaning more stable blood sugar levels)
- weight loss/weight maintenance
- lowered risk of cardiovascular disease
- lowered risk of diabetes
- convenient (only have to worry about a few meals each day)
- increased productivity during your fasting window
- improved digestion (you are literally giving your digestive system a 12-16 hour break, so that it's not constantly having to break down and process food)
There is also a great article by Martin Berkhan that goes into even more detail about IF, that you can check out here.
Choosing a schedule
If you decide to try out IF, I would recommend starting out slow - you could start with a 12:12 schedule (i.e. eat from 8 am - 8pm), and then work your way up to 14:10 or 16:8, if you find that you're liking it. It does take about a week or two for your body to adapt, but if you're drinking enough water during your fasting window, and consuming enough calories during your feeding window, your body should get used to it fairly quickly. Again, if you feel like your body is fighting back hard, or you experience any blood sugar or other medical issues, definitely don't force yourself to continue!
One other aspect of IF that I'd like to discuss is the fact that men and women seem to thrive on different eating schedules. Women's hormones are much more sensitive to signals of starvation, and the research I've seen states that women generally do best on either the 14:10 or 16:8 schedule. Men, on the other hand, have been found to do well on a variety of schedules (i.e. 16:8, 20:4, etc.). With that being said, I still recommend listening to your body and what it's telling you - we're all different, and so are our bodies.
One last topic I wanted to touch on briefly is exercise. There's SO much research out there about whether it's better to train in a fasted or fed state - from what I can gather, the benefits of both are pretty similar. Again, I would encourage listening to your body - I know some people that can't even have a piece of toast before exercising, or they feel sick, and I know others who feel weak and dizzy if they're not training on a full stomach. Do what feels best to you!
I'm so happy I finally got around to writing about IF - it's positively impacted my life in so many ways, and I'm so thankful that I tried it out. Not only do I now feel like I have a better relationship with food, but practicing IF has helped me stop using food as an emotional crutch, and start appreciating it for all the nourishing, healing properties it has.
If IF is something that you're intrigued by, and you want to try it out, start slow! You don't have to be jumping into 16 hour fasts right away (I definitely didn't). And don't forget - if it's not working for you, that's completely fine. I hope you all enjoyed this post! It was actually really beneficial for me to write it, as it allowed me to reflect back and see how far I've come in terms of my relationship with food, and overall wellness. Thanks for reading! xo