In this article, you are going to learn how to start intermittent fasting. This simple, healthy lifestyle trick is going to help you simplify your day, control your hunger (or hanger), increase energy levels, and maintain a lean figure.  

Our Intermittent Fasting How To Guide will walk you through the challenges to overcome, and the process to be successful.

Don’t skim this too fast. You want to feast on this information!

intermittent fasting how to guide ryan and alex duo life

intermittent fasting how to guide

This is an in-depth post on how to start intermittent fasting. Before we dive into the step-by-step plan, we’ll share our experience with intermittent fasting as well as the rules and definition of intermittent fasting.

We have been researching and self-experimenting with fasting since 2018. For additional well-researched content backed by personal experience, check out the articles on our fasting page.

So, let’s start at the beginning when we were skeptical of intermittent fasting and scoffed at the thought of skipping breakfast.

Vetting Intermittent Fasting

We have been in the health industry for a combined 17 years, obsessing over nutrition books, podcasts, and all the new diet trends.

As engineers, we love learning about the science behind new diets like the dieting pattern, intermittent fasting.

We will be long-term intermittent fasters, and we recommend it to all.

However, when the fasting trend first began, I was extremely critical of it because it seemed like deprivation. Once it was too popular to ignore, we ran it through our diet vetting process.

  1. It’s not a fad, short-term diet (anything calorie or macronutrient restrictive)
  2. There’s considerably more science for the diet than against (shouldn’t be too controversial)
  3. Major diet influencers are not marketing or selling supplements or products to dieters
  4. History shows that the healthiest, longest-living populations followed the diet

It passed. I was surprised because most don’t.

For example, the popular new diet, Keto, never passed our vetting process. It’s restrictive, fueled by a large business, and goes against a wealth of data on eating primarily plants instead of primarily animal products.

For intermittent fasting, there is ample historical evidence that fasting is beneficial, it encourages a well-balanced diet, and there is no business fueling its popularity because it’s too simple.

Starting The Diet

So, it passed our rigid diet vetting process, meaning, the next step was to self-experiment with intermittent fasting for three months to document how we felt.

For me, the scariest part about starting intermittent fasting was working out on an empty stomach and missing breakfast.

I have always preferred working out in the morning before getting lost in my to-do list, and I was not too fond of doing that on an empty stomach.

What’s more, I always told my clients that breakfast is the most important meal of the day, followed by two more meals and two snacks spaced out every few hours.

Was I wrong? Maybe.

How was I going to feel missing breakfast? Probably super cranky since I already had a major hanger issue.

After more research, feedback from fasting friends, and a thorough Q&A on intermittent fasting with thought leader, James Clear, we decided to go for it.

I was sold at, “You don’t need to miss breakfast food, just eat a breakfast feast later in the day.”

In March 2018, we both started intermittent fasting according to the daily intermittent fasting plan, which is typically a 16-hour fast (8 of which you are sleeping) and an 8-hour eating window.

During the first three months, we carefully journaled the changes and the challenges we experienced. Next, we’ll share those key takeaways from our journaling.

What Surprised Us About Intermittent Fasting

There are numerous scientifically proven health benefits of intermittent fasting. Yes, both weight loss and muscle gain are included. But, it’s not for everyone, and everyone who follows intermittent fasting has an opportunity to maximize their results.

For a deep dive into the benefits, who’s it for, and how to maximize results, check out our article, ‘Intermittent Fasting Health Benefits.‘ The following are surprising benefits we experienced.

  1. Instead of hanger worsening, within three weeks it disappeared, and I could control my hunger
  2. Fewer meals and less time thinking about food massively simplified our day
  3. Intermittent fasting encouraged more sleep and a more structured routine
  4. Working out and intermittent fasting was not an issue at all, and we both became leaner
  5. We enjoyed our breakfast feast later in the day and our new morning rituals

To clarify, this is what surprised us after three months following the daily 16/8 intermittent fasting plan. There are other types of intermittent fasting.

Intermittent Fasting Definition

Technically, intermittent fasting isn’t a diet. It’s a dieting schedule or dieting pattern.

There are no official rules on what to and what not to eat. Intermittent fasting regulates the hours of which you eat.

There are a few different definitions of intermittent fasting. There is “daily intermittent fasting,” which is what we do following the 16/8 plan.

Then, there is “weekly intermittent fasting” and “alternate-day intermittent fasting,” which involve periods of 24-hour fasting once weekly and every other day, respectively.

Daily intermittent fasting involves eating your daily calories in a shorter time and fasting for the rest of the day and night.

The most common intermittent fasting plan is 16/8. That involves 16 hours of fasting (including sleep) and 8 hours of eating. Anything between 12/12 and 20/4 is considered intermittent fasting by most. 

Alternate-day fasting is the method used in most research studies on the health benefits of fasting, such as increased longevity. It mimics the feasting and fasting that our ancestors experienced out of necessity, in times when food was scarce.

A typical alternate-day fast plan starts in the evening with one 24-hour period of feasting followed by one day of fasting.

An excellent example of these research studies is this one published by the Blue Zones. Weekly intermittent fasting is similar. However, fasting only occurs for 24 hours once weekly.

Fasting Plans We Follow

We have done daily intermittent fasting and extended fasting (3 days) and the ProLon fasting-mimicking diet (5 days).

In our opinion, it’s much easier to form a routine around 16/8 plan. Therefore, this intermittent fasting how-to article is for those of you starting daily intermittent fasting.  

For those of you interested in a healthy intermittent fasting meal plan, well done. While intermittent fasting studies show you don’t have to change your diet whatsoever to lose weight, that’s not a pass to eat like crap. 

Below, you can download our printable intermittent fasting meal plan for both 16/8 intermittent and alternate-day fasting.

If you’re curious about doing an extended, 3-day fast, props to you again. You should be. While it seems extreme and daunting (it did for us) it’s actually quite easy. We did all the research and created a plan that will help you be successful.

Open the below article in a new tab to hear our before, during, and after story, results, and plan that you can replicate.

Intermittent Fasting Rules

There are very few rules. Actually, there is only one rule for the daily intermittent fasting 16/8 plan.

  1. Eat during an 8-hour window during the day and fast* for the other 16 hours.

* Fast means no food or calorie-containing beverages. You can and should drink water during fasting, but, any drink that is more than 50 calories is not allowed. Other allowed drinks include unsweetened teas and coffee, as well as infusions like lemon water.

Lastly, let’s review the intermittent fasting pros and cons before we dive into the Intermittent Fasting How To Guide.

Intermittent Fasting Pros And Cons

The health benefits of intermittent fasting and the science behind the diet are becoming more widely known. These are the pros and cons that we have experienced firsthand.


  • Higher functioning body and mind
  • Control over hunger
  • Encourages consistent sleep schedule
  • Simplified day
  • Weight management


  • Hunger in the morning and at night
  • Eating the same amount of food in a shorter time requires your appetite to adjust
  • Falling asleep is hard if you’re hungry
  • The eating schedule doesn’t match that of the general population

So, that last point is the only one that is a “con.” The other points, about hunger and the feeling of stuffing yourself during the day, aren’t permanent. Instead, once you start intermittent fasting, they go away rather quickly. For us, within a month.

Unfortunately, you will always have to deal with not eating breakfast or dinner when most people do. But you can plan and do your best.

For example, I was recently on an ice fishing trip with twelve guys. We had to eat breakfast before the fish bite, and that starts at sunrise. Instead of eating at 6 AM with the rest of the guys, I enjoyed a coffee while they ate, and packed food to eat later on the ice.

Intermittent and extended fasting bundle - printable pdf guide

The Proven Fasting Bundle (Printable PDF Guide)

Read by 143,364 fasters in 2022 alone, the Fasting Bundle is the structure and tools you need to succeed.

  • Intermittent and alternate-day fasting meal plans
  • Checklist for before, during, and after a prolonged fast
  • Benefits, challenges, and a beginners how-to guide

Plus, we're just an email away for support.

Our Intermittent Fasting How To Guide

The Intermittent Fasting How To Guide is a step-by-step plan to transition from your current eating schedule to intermittent fasting.

We’ll start with advice to help you set the right intentions for intermittent fasting.

Disclaimer: Intermittent fasting controls when you eat, not what you eat. The healthier your diet, the better your results. If you’re taking any medications or have diabetes, low blood pressure, are pregnant, or have a history of an eating disorder, consult your doctor before starting intermittent fasting.

Step 1: Check Your Intentions

1.1 – You’re committed for the long(ish) term

In response to diet changes, your body and health change gradually. Therefore, plan to stick with intermittent fasting for at least three months to realize the benefits. At that point, you can decide if it’s right for you.

1.2 – Commit for the right reasons

Instead of focusing on weight loss, pay close attention to how intermittent fasting makes you feel and nudges you toward a healthier lifestyle. While journaling, ask yourself daily, “Do I feel healthier?” Our bodies share this feedback if we listen.

Once you’re consistently feeling healthier, the weight won’t stick around long-term. Excess body fat is like a family of raccoons. Once you clean up your diet and eliminate the trash, they’ll move out.

1.3 – You have accountability

Recruit your spouse, significant other, sibling, or best friend to start intermittent fasting with you. This added accountability significantly improves success rates.

Step 2: Intermittent Fasting Calories

2.1 – Measure your current DCI

You don’t need to count calories every day. However, since you’re starting a new diet, it’s critical.

Measuring your current daily caloric intake (DCI) will help you put your best foot forward.

Trying to be healthy without knowing your calories is like trying to train for a race without knowing the distance. The best tool for doing this is the free MyFitnessPal app.

Does your DCI fall within a healthy range (i.e., no less than 1200 for females and 1600 for males)? Is your DCI higher than your basal metabolic rate (BMR)?

Your BMR is the number of calories your body burns daily just to sustain life. If you’re eating fewer calories than that number, your metabolism is suffering, and your body is hoarding calories as body fat.

Yes, I know, counting calories is tedious. But, I bring this up for an important reason: most people wanting to lose weight are not eating enough calories.

When you eat too few calories, your hormones become out of whack and you could actually gain weight! Eating too little is like starving a flower of water. It doesn’t get skinny, it just becomes weak and malnourished.

2.2 – Eat your calories in less time

Assuming you were eating the right amount of calories, you need to consume the same amount of calories in a shorter time.

Therefore, your meals will be bigger. We went from three meals and two snacks daily to two meals and one snack. Our meals are feasts!

If you learned that your DCI was in deficit or excess, start adjusting your food intake day by day until you’re consistently meeting your DCI goal. Set a goal to check your calories at least monthly.

2.3 – Don’t skip this

Please do not skip steps 2.1 and 2.2.

Again, we work with tons of couples who have the goal of losing weight and 9 out of 10 are not eating enough calories. It’s a losing battle. Need help with your DCI and BMR? Check out our 30-Day Weight Loss Challenge for your calorie calculations.

Or, sign up for our Couple’s Clean Week, and we can work with you directly to nail down your calories and a healthy diet.

Step 3: Make A New Routine

In this step of the Intermittent Fasting How To Guide, you’ll make a new routine around your intermittent fasting schedule.

In the following steps, I’ll share examples of how our morning, afternoon, and night routines changed, along with tips on how to start intermittent fasting successfully.

3.1 – Common fasting schedules

Although it’s completely flexible, there are two common intermittent fasting schedules.

For the early risers, who wake up at 4 or 5 AM, breakfast at 9 AM and an early dinner before 5 PM works well. For those who  wake up between 7 and 8 AM, lunch (you can still eat breakfast food) at noon and dinner before 8 PM is common.

To make your schedule, target eating your first meal 4-5 hours after waking and finishing your last meal 3-4 hours before bed.

3.2 – Morning routine

For nearly all intermittent fasters, morning presents the biggest challenge.

When I started, my routine was to wake up early, work out, eat breakfast, and drink a cup of coffee while reading a personal development book or starting work for the day. Once I started intermittent fasting, these activities shifted.

First, I started sleeping more when I began intermittent fasting. Since I wrote an entire article on the importance of combining intermittent fasting with quality sleep, all I will say is that sleep counts as fasting.

Spending 7-9 of your fasting hours sleeping is not only healthy, but it makes intermittent fasting much easier.

For intermittent fasting beginners, morning hunger is inevitable. To fend off this hunger, drink lots of water as well as a distraction drink.

What can you drink during intermittent fasting? Water is best, but any drink containing less than 50 calories (that means no coffee creamer) will not break your fast.

So what’s a distraction drink? The ritual of preparing and drinking something (in addition to lots of water) was helpful to distract us from our grumbling stomachs. We prefer drinking fresh coffee prepared with French press, yerba mate tea, or our favorite digestive enzyme drink.

Digestive Enzyme Distraction Drink:

  • One cup of hot water
  • One half a lemon squeezed (excites digestive enzymes)
  • Two caps full of apple cider vinegar (balances pH levels in the gut for healthy bacteria growth)
  • A pinch of cinnamon (to stabilize blood sugar levels).

While enjoying our distraction drink, we read a good book before starting our morning workout.

Intermittent fasting and morning workouts can be scary at first. However, if you currently do morning workouts, it’s less challenging than you think to work out while fasting.

You can work out in the morning while you’re in a fasted state, or the afternoon in a fed state.

After our workout, we begin our daily work activities. At 11:30 AM, we break to cook a breakfast feast and start eating at noon, which is the beginning of our eating window.


Expect to rearrange your morning slightly. Consume lots of water and a distraction drink to fight hunger.

Also, be mindful of your energy levels and ability to focus in the morning with your new routine. For example, here is my morning routine shift.

3.3 – Afternoon routine

The afternoon is when you’ll likely be focused on eating and working. We prefer to eat two big meals along with afternoon snacks. In the afternoon, we usually have a smoothie and healthy snacks, such as kefir and granola.

As an intermittent fasting beginner, you might not be hungry in the afternoon since you’re not used to eating all daily calories in such a condensed time. However, it’s still critical to eat all your meals and snacks.

If you miss one because you’re not hungry in the afternoon, the hunger pangs that strike in the morning or night could knock you off the bandwagon. Therefore, set a reminder alarm on your phone and schedule afternoon meals and snacks.

3.4 – Night routine

According to the intermittent fasting 16/8 plan, you should finish dinner 8 hours after you started breakfast. Schedule a big dinner within this time. Again, it’s best to eat dinner 3-4 hours before bed. If you start getting hungry, it’s time for bed!

Don’t be too strict. If life happens and you eat dinner too late or you need to eat breakfast early before an appointment, no stress. When you start intermittent fasting, there might be times (usually early morning and late night) when you are miserably hungry. That’s normal, and you have my permission to eat a banana with peanut butter.

Step 4: Optimize your plan

Once you start feeling the benefits of intermittent fasting, take the opportunity to optimize your day. For example, you might want to experiment with the below and decide what makes you most productive.

  • Do the majority of your work in the morning since you’re more focused
  • Work out in the afternoon when you’re less hungry
  • Go to bed earlier so you can get a full night’s rest and have your first meal earlier
  • Make your distraction drink later in the morning after you’ve drunk lots of water

What we love most about intermittent fasting is it has helped us not only simplify our day but it’s encouraged us to optimize our healthy lifestyle. More on that in Step 5.

Step 5: Embrace Continuous Improvement

Intermittent fasting isn’t a diet. It’s a lifestyle change. It won’t work unless you work. You need to embrace continuous improvement.

5.1 – Eat cleaner

The healthier you become, the more significant the effects of intermittent fasting. Meaning, if you’re still drinking soda and eating processed foods, you might not feel the difference of intermittent fasting at all.

What’s more, eating junk food while intermittent fasting will negate the benefits and could even be more harmful to your health. Also, I don’t want to have to say it again. Stop drinking soda.

Sometimes, intermittent fasting beginners binge eat and consume too many calories during their eating window. They usually do this because they are starving in the morning or at night.

This problem is almost always caused by poor nutrition. If you’re eating foods with low nutrient quality, your body is going to crave more food because its nutrient tank isn’t full.

A healthy diet is critical, and we dive into the science behind that in this article on maximizing the health benefits of intermittent fasting.

5.2 – Apply bonus time to your healthy lifestyle

What are you going to do with your extra time?

For us, we went from reading one book per month to 3-4 books. Intermittent fasting creates more time since you don’t have to think about, prepare, and eat as many meals.

Instead of having to plan for three meals and two snacks daily, you can focus on two meals and one snack.

5.3 – Consistent sleeping routine

Intermittent fasting is not like other diets, where you have to count calories, measure your food, eat only certain foods, etc.

Instead, there is only one rule for intermittent fasters to follow. Eat within your eating window. When you only need to follow one rule, keeping the routine is much easier.

Why not take this same rule and apply it to the essential routine, your bedtime routine? Spending more time sleeping and less time eating (intermittent fasting), frees up resources in your body.

Now, these resources can spend more time cleaning up waste, reducing inflammation, and boosting brain and body performance. Intermittent fasting and sleep go hand-in-hand.

Closing Thoughts on How To Fast Correctly

We hope this article has helped you understand how to intermittent fast properly. 

Please download our Proven Fasting Bundle (below) to help you reach your goals and leave any specific questions about fasting in the comments below. We prefer that to email because the discussion helps all future readers. Thanks!

For general questions about fasting, such as why you’re not losing weight on intermittent fasting, head over to our Fasting Page.

Intermittent and extended fasting bundle - printable pdf guide

The Proven Fasting Bundle (Printable PDF Guide)

Read by 143,364 fasters in 2022 alone, the Fasting Bundle is the structure and tools you need to succeed.

  • Intermittent and alternate-day fasting meal plans
  • Checklist for before, during, and after a prolonged fast
  • Benefits, challenges, and a beginners how-to guide

Plus, we're just an email away for support.

30-Day Weight Loss Challenge Tracker Form V2 Ryan and Alex Duo Life

30-Day Weight Loss Challenge

As engineers with a combined twelve years of health coaching experience, we needed to create a data-driven way for our clients to sustain weight loss.

Too many weight loss challenges involve a long list of what you can, cannot, and need to do every day. We’ve reduced the overwhelm and only require you to track five numbers a day — calories, steps, fiber, sleep, and waistline.

You’ll track five numbers daily to give you the highest return for sustainable weight loss. As a bonus, we’ll share our Weight Loss Bundle, which includes strategies, progress tracking tools, and additional weight loss plans.

Learn more about the program.

As Seen In Feature Bar Ryan and Alex Duo Life

Hey we're Ryan and Alex

The creators of Ryan and Alex Duo Life. We are a husband-wife duo and “lifestyle engineers.”

After eight years working in the corporate world as engineers, we left our high-powered jobs to tackle our true passion — helping couples engineer their best lives.

The synergy of our engineering minds and ten years of health coaching experience produced Ryan and Alex Duo Life. Our mission is to help you transform your bodies, minds, and relationship as a couple.

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