Intermittent Fasting 101: The Ultimate Beginner's Guide to Time-Restricted Eating

Intermittent Fasting 101: The Ultimate Beginner's Guide to Time-Restricted Eating

When considering health and weight loss trends, it's hard to decide which ones are reliable and which are unsafe. It seems like a new trend pops up every other day, including the Baby Food Diet and the Cookie Diet (yes, these are real).

The problem with most of the fad diets is that they're restrictive, unproven, and are flat-out unrealistic for any of us to stick within the long run. However, intermittent fasting (a.k.a. time-restricted eating) is a more sustainable eating pattern. It's an established lifestyle that has been around throughout history and is still practiced in multiple cultures across the globe. Keep reading to get your quick crash-course on how to do intermittent fasting.

What Is Intermittent Fasting?

intermittent fasting

Let’s start at the beginning with the basics of an intermittent fasting lifestyle (also known as time-restricted eating). Intermittent fasting (“IF” for short) is focused on when you eat, rather than a traditional diet of what you eat.

It's the process of intentionally following an eating pattern where you are allowed to eat between a certain window of time and voluntarily refrain from eating during the other hours.

You might not realize it, but everyone fasts intermittently during the night. Anytime you’re not consuming calories is considered fasting, so yes, when you’re sleeping for 7-10 hours every night, you are in fact intermittent fasting! Once we're awake, we "break-fast", and then eat periodically through the remaining 14 to 12 hours of our day.

Intermittent fasting is making the most of this normal cycle by creating personal eating and fasting windows. The idea is that by restricting how often we eat we allow our body to make necessary cellular repairs and may reduce overall calories.

It’s a very attractive lifestyle, as it doesn't require eliminating entire food groups or sticking to a rigorous, unrealistic diet (say goodbye to your juice diets).

The History of Intermittent Fasting

Aside from the natural fasting we all experience while sleeping, fasting has been around throughout human history. It's perhaps as ancient as human history itself. Think about it: in pre-civilized times, we couldn't walk to our refrigerators to eat a snack whenever we wanted. Rather, humans had to wait long periods between meals depending on a successful hunt.

Since then, we've also seen intermittent fasting as a spiritual or cultural norm.

Many Christians fast during Ash Wednesday and Good Friday. Muslims refrain from eating sunup to sundown during Ramadan for nearly a month. And many Buddhists employ intermittent fasting daily as a means of mental clarification.

In the religious context, refraining from food is a way to purify the body, mind, and spirit. We see the same concept applied in other settings, such as Ayurvedic medicine, as a means of healing. Even in the Western tradition, one of the fathers of western medicine, Paracelsus stated that "fasting is the greatest remedy". Intermittent fasting isn't a fad trend -- it's an integral part of human nature.

How It Affects Your Body

The concept surrounding fasting is simple: we're either taking in food for energy or we're utilizing previously-stored energy in fat cells. When we aren't eating, we're burning through our energy reserves.

intermittent fasting and blood pressure

There is research that backs up the idea that intentional time-restricted eating can facilitate weight loss and improve metabolic measures. The benefits don't stop there, either. Intermittent fasting can reduce cardiovascular risk factors by lowering "bad" cholesterol, blood triglycerides, and blood pressure. Additionally, it may lower blood insulin and sugar levels.

Metabolism is also thought to kick into overdrive while fasting to use the stored fat as energy. As a result, our systems are more resistant to oxidative stress, inflammation decreases throughout our bodies, and we may even live longer.

Aside from these incredible benefits, many people report feeling heightened mental clarity, improved concentration, and all-around more energetic. If you're in good health, the main side effect of this modified eating pattern is slight hunger pains.

Intermittent Fasting 101: The Starting Point

intermittent fasting healthy food

Looking to try out fasting for yourself? Here's what you'll want to do. First, stock up your refrigerator with healthy foods. It's not a requirement for this eating plan but it will help you maximize the results.

Eating junk and processed food during your eating windows isn't healthy and is contributing more sugar and empty calories to your system. Once you have the supplies to eat a balanced meal plan, you’ll want to take a look at your sleep. On average, how much do you sleep every night? Most adults need 7-9 hours per day.

To begin with an intermittent fasting lifestyle, you'll want to factor the time you're sleeping in to your fasting window. The easiest schedule to follow when you start fasting is to refrain from eating 2 hours before bed, sleep for 8, and wait 2 hours after waking up before having breakfast. This is a great starting point to a 12 hour fast. The best part is that you’re asleep for most of the fast.

12:12 is an easy place to start (especially if you're not a nighttime snacker). Once you feel comfortable with 12:12) you can move towards a 14:10.

A 14:10 may look like this: refraining from eating 3 hours before bed, sleeping 8 hours, and refraining from eating 3 hours after you wake up.

Whenever starting a new "phase" or type of intermittent fasting, give your body at least a week to adjust before throwing in the towel. Once you start working up to 14 hours or more of fasting per day, you'll want to stick with your fasting period for a while before trying to increase fasting time.

Overall, the idea is to take it slow and gradually increase the length of fasting over a reasonable period. This will allow you to recognize if it's a healthy solution for you and to see if you feel the desired results.

Different Types of Intermittent Fasting

Intermittent fasting regimens differ in duration. Some are more extreme than others, but we'll start off with the mildest methods and work our way up from there.

12:12 and 14:10

The 12:12 and 14:10 windows refer to fasting for 12 or 14 hours and eating all meals during a 12 or 10-hour period. This isn't too far off of our normal habits, making it an easy adjustment. With this schedule and the rest, it's important to keep your timing the same. Try eating from 9 am to 7 pm every day, rather than shifting around your "eating window".


The 16-hour fast is also known as the Leangains protocol. It was initially developed by Martin Berkhan as a tool for weightlifters and bodybuilders. It focuses on skipping breakfast and refraining from eating after dinner.


The 5:2 approach is where you eat normally for 5 days of the week and for the remaining 2 days, you only eat 500 (women) or 600 (men) calories. Just like other fasting methods, this one is only effective if you eat normally during your allotted eating times. If you're limiting calories on, say, a Monday and a Friday, it’s important to not overeat on other days of the week.


"One meal a day" is exactly how it sounds: you only eat once a day. This may be the most difficult intermittent fasting option. If you work your way up to this one, you should have a plan for how long you're going to do it as well as a plan to moderate eating after you stop the fasting period.


Eat-stop-eat takes the 5:2 approach one step further.

In this intermittent fasting plan, you would eat normally for 5 days and fast completely for the other two days. This isn't a plan that you would start with but one you could work your way towards.

Additionally, fasting for 2 days out of your week may not be sustainable long-term. It's better to go for something that works for you as a lifestyle change, not simply a short-term push. Otherwise, the benefits of intermittent fasting may be short-lived.

A Few Things to Keep In Mind

Intermittent fasting is restricting the times in which you eat to decrease overall calorie intake and feel healthier. So, if you're binging or over-eating during your eating window, it's not going to do much for you.

Additionally, it might not be the best eating modification for everyone. It should be avoided entirely if you:

  • Breastfeed
  • Are pregnant
  • Are under the age of 18
  • Are underweight
  • Had/have eating disorders

Limited studies are supporting these demographics, so it's better to be safe and avoid this lifestyle change if you fit those categories. It's always wise to consult with your doctor before making big lifestyle changes. This is especially true if you:

  • Have diabetes, blood sugar issues, low blood pressure
  • Take medications of any kind
  • Are trying to conceive a child
  • Have a history of amenorrhea

In general, fasting is considered safe if you are within normal health. If you aren't, you can talk with your doctor and determine if it's right for you.

Listen to Your Body

Just like any other eating modification, the effectiveness of fasting depends entirely on your own body and lifestyle. With this intermittent fasting 101 guide, you can see if it's right for you. Give your body time to adjust, modify it to fit your needs, and listen to your body throughout the process.

Keep reading our blog to see Why Intermittent Fasting Might Be Right For You!