A diet that is super easy to follow and also has heaps of health benefits, way beyond just weight loss. That’s pretty much the dream combination, right? Welcome to the beginner’s guide to intermittent fasting. We’re here to break it all down for you, so you can even start today if you’d like!
What is intermittent fasting?
Intermittent fasting is as simple as a schedule that divides your day into two parts: an eating window and a fasting window. While most diet plans are fundamentally concerned with WHAT you eat, this plan is all about WHEN you eat, and that’s it.
There’s no meal planning, no shopping lists or other advance preparation. You can customize your eating schedule based on your lifestyle, and then all you have to do is follow the schedule! The structure of intermittent fasting is meant to make the most of your body’s natural metabolic processes every day, so that you can be on your way to long-term optimal health.
The Benefits of Intermittent Fasting
Intermittent fasting might just be the simplest diet you’ve ever encountered, and it has something for everyone–whether you’re looking to lose weight, increase your athletic performance or boost your brain health. In fact, the results are so potent, they almost seem to good to be true. We were skeptical too, so we’ve compiled a list of all the health benefits supported by scientific studies:
1. Weight loss and maintenance
By training your body to burn fat for energy, intermittent fasting will tap into your body’s natural weight loss mechanisms. Plus, the simplicity of the plan means you’re much more likely to stick with it!
2. Increased energy
Unlike so many calorie restriction diets that can make you feel sluggish, the intermittent fasting schedule is designed to regulate your hormones so that you’re always easily accessing stored fat for energy. No more afternoon slumps!
3. Increased mental clarity and focus
Intermittent fasting has the ability to boost your brainpower because it increases your BDNF, which supports brain connectivity and new neuron growth. (1)
4. Better cognitive function
The hormonal changes that occur when you follow intermittent fasting have actually been shown to provide protection against neuro-degenerative diseases like Alzheimer’s and dementia. (2)
5. Regulated blood sugar and insulin levels
The quickest and most efficient way to lower insulin levels is through fasting. While you’re in your fasting window, no new glucose is being supplied to your body, which means your body has no choice but to use up stored glucose. (3)
6. Lower cholesterol and blood pressure
Intermittent fasting is an excellent prescription for heart health, because of its ability to decrease your liver’s production of cholesterol. Studies have shown that 70 days of alternate-day fasting can reduce LDL cholesterol by 25 percent. (4)
7. Reduced inflammation
Your body relies on a process called “autophagy” to clear out old and damaged tissues and cells. When you fast and give your body a break from the constant effort of digesting food, it seems to be able to focus more energy on repair, which means alleviating inflammation in the body. (5)
8. Increased metabolic rate
When you practice intermittent fasting and successfully switch your body into fat-burning mode, your body is actually using adrenaline to release stored glycogen and access fat to burn. These increased adrenaline levels will speed up your metabolism. (6)
9. Long term anti-aging benefits
Types of Intermittent Fasting
There’s a wide variety of intermittent fasting schedules to choose from. Your choice will depend on factors such as your lifestyle, health goals, sleep cycle, exercise schedule and more. If you have no experience with fasting, we recommended starting with a 12-hour eating window and a 12-hour fasting window. After that, you can progressively move to the 16:8 plan, which is the most commonly used schedule.
The 16:8 plan
Eat during an 8-hour window and fast for 16 hours.
Sample schedules: Only eat between 11:00 a.m. and 7:00 p.m OR only eat between noon and 8:00 p.m.
The 18:6 plan
Eat during a 6-hour window, fast for 18 hours.
Sample schedules: Only eat between 10:00 a.m. and 4:00 p.m OR only eat between noon and 6:00 p.m.
The 5:2 plan
Pick two non-consecutive days of the week and only eat 500-600 calories on those days. These are your “fasting” days. You would then eat normally during the other 5 days of the week.
The 24-hour fast
Did you know you can do a 24-hour fast and not actually skip a day of eating? What? What magic is this? Think about it: you’re having a normal Wednesday and you intentionally stop eating by 7:00 p.m. Thursday dawns and you give your digestive system a little break from all the hard work it does – you know, keeping you alive and stuff – and then you sit down to a nice dinner at 7:00 p.m. Congratulations, you’ve just completed a 24-hour fast but you didn’t have an entire day of no food. (Please note, it is not recommended to incorporate a 24-hour fast more than twice a week.)
Frequently Asked Questions
How can an eating schedule have so many benefits?
Turns out, the time we spend eating can be just as important to our health as the foods we are eating. Here’s why: at any point in time, your body is either “fed” or “fasted.” While you might assume that your “fed” time only includes the time spent eating, it actually refers to the 8-12 hour period of time in which your body is digesting and absorbing the food you’ve eaten.
So let’s say you finish eating dinner at 8pm. Your body actually remains in a fed state until approximately 4-8am. Only then does your body enter the fasted state. Assuming, of course, you haven’t already started eating breakfast!
Why should you care about whether or not you’re in a fasted state? Because that is where all the good stuff happens. Not only does your body shift to burning stored fat once it enters the fasted state, but a number of other metabolic changes happen here that are responsible for the wide array of health benefits described above. (9)
Getting into the fasted state is actually pretty rare for most of us. That’s why the sole purpose of intermittent fasting is to allow your body to get into a fasted state and stay there for a couple hours.
So when can I eat?
Hands down the most popular intermittent fasting plan is called the 16:8. It means you fast for 16 hours and eat during the remaining 8 hours of your day. We’ve created a handy chart you can use to keep track, which you can download here.
The best part is that you can start your 8-hour window anytime you want. For example, you can try skipping breakfast and only eating lunch and dinner. Need your breakfast? No problem, just skip your dinner instead. Experiment with different windows until you figure out what works well for your lifestyle and personality, and what makes you feel physically at your best.
What can I eat?
Because intermittent fasting plans are purely concerned with WHEN you eat, it’s easy to get confused about WHAT you should be eating during your eating window. Technically, intermittent fasting has no rules about this. You’ll find many intermittent fasting guides that tell you to eat whatever you want.
That being said, it’s common sense that the benefits you reap from fasting will be limited by your food choices while eating.
We’ve put together a helpful guide on what you can eat and drink in order to maximize the benefits of intermittent fasting.
If you happen to be following a Ketogenic (“Keto”) diet or have been considering one, it actually complements intermittent fasting very well. You can read more about combining the two here.
What can I drink?
During your fasting window, you need to refrain from consuming any food or beverages that contain calories. So….. no food. But you have several beverage options, and these are important because it is critical to keep yourself hydrated while fasting.
Here’s a quick-start guide to the drinks that can help your fasting journey, and if you’d like to read more details about What to Eat and Drink While Intermittent Fasting, you can check out this post.
Can Tea Really Make a Difference while Intermittent Fasting?
Yes! Science is unanimous on the fact that drinking tea not only make fasting easier, but it will actually increase the health benefits you experience. Read all about the amazing ways tea enhances your fasting experience, and how much to drink, here.
Won’t I be tired while fasting?
This super common concern about fasting has actually been disproven time and time again. Because intermittent fasting provides your body with more breaks from the digestive process, it will actually give you more energy and boost your productivity.
And if you’re worried that you won’t be able to keep up your regular fitness routine while fasting, not to fear. Studies show that exercising while following an intermittent fasting plan can actually be even more beneficial than just exercise alone. (10)
Isn’t fasting bad for my metabolism?
Quite the opposite! Long-term starvation diets can certainly harm your metabolism, but an intermittent fasting schedule has actually been proven to boost the metabolism (11). And while many weight loss programs result in loss of lean muscle mass, intermittent fasting only targets your stored fat, so you get to preserve all your muscle tissue, which is so critical in keeping your metabolism humming along (12).
I’m terrible at diets, how do I stick through them?
You’re not alone. But people who try intermittent fasting overwhelmingly discover that it is surprisingly easy to implement. The main reason diets fail is because behavior change is hard. But with this, there’s only one rule to follow, and there’s zero advance planning.
In other words, it’s simple enough that you’ll actually be able to keep it up! There’s even scientific research indicating that “subjects quickly adapt” to an intermittent fasting plan, making it a highly effective technique (13).
When can I expect to see results?
As with any diet, results certainly vary. However, in most cases, you might have a one to two-week adjustment period where you experience lethargy or hunger cravings. We highly recommend drinking tea to help you out, as it will quell your cravings, boost your energy, and assist in detoxification.
And despite this adjustment period, most people will lose one or two pounds in their first week and will subsequently start to see their energy levels and mental alertness rise while their cravings and excess fat disappear.
Is intermittent fasting really for everyone?
If you are a woman, it’s possible that intermittent fasting may affect you differently. In general, it seems that women tend to respond better to using a schedule that has a wider eating window. For example, some women have noticed increased health benefits by using a 10-hour eating window with a 14-hour fast, instead of the 16:8 plan popularized by male bodybuilders. You can read an in-depth guide on intermittent fasting for women here.
As with any diet or exercise plan, we recommend trying different options and listening to your body to see what works best for YOU. There’s a fantastic all-female intermittent fasting Facebook group here for you to check out if you’d like to connect with other women about their experiences.
Also, if you are diabetic, hypoglycemic, have any issues with blood sugar regulation, are pregnant or breastfeeding, or have a history of disordered eating, intermittent fasting may not be for you. You should talk to your doctor before making changes to your eating schedule.