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Intermittent Fasting Guide for Beginners (2023 Updated)

Isaac Robertson
Published by Isaac Robertson | Co-Founder & Chief Editor
Last updated: August 12, 2023

Intermittent fasting isn't a diet, as many people think. It is a way of scheduling your meals at specific times. Through this, your body will maximize each nutrient you consume in your diet. Intermittent fasting is gaining popularity across the globe as it helps with weight loss.

Weight gain is linked to eating more calories when compared to the one getting flashed out of the body. Basically, intermittent fasting doesn't focus on the kinds of meals you consume rather than the time you dine.

This way of eating has also been attributed to reduced inflammation and reduction effects of chemotherapy.  Below is everything you need to know about intermittent fasting before trying it out.

Quick Summary

  • Intermittent fasting is voluntary meal timing scheduling at any preferred set interval.
  • Intermittent fasting guide helps in weight loss as it limits calorie intake per day.
  • Intermittent fasting, when combined with exercise, can give you gain more lean muscle and also enhance endurance.
  • Scientifically, intermittent fasting has been proven effective in reducing inflammation.

What is Intermittent Fasting?

Plate in a clock shape

Intermittent fasting is scheduling your meals for specific time intervals so that your body gets the most benefit out of it.

The results of intermittent fasting (IF) for weight loss can be astounding.

This plan isn't focused on which foods you eat (or often even how much). Rather, it's when you eat that makes all the difference.

These fasts can last anywhere from 16-36 hours and are usually repeated several times throughout the week.

The main idea of Intermittent Fasting is that you undergo a series of short term fasts to lower the amount of calories you eat in a day while also revving up your metabolism to its full fat-burning potential.

A food fast can be as simple as eating a big dinner and then not consuming anything but tea or coffee until 1pm the next day. Lunch and dinner are then eaten normally after this fasting phase, and the process can be repeated over again.

It's an easy diet to stick to because you can start it with minimal preparation, but the results are so effective that they will keep you motivated for the long term.

As an added benefit, following an IF meal plan supplemented with exercise can help you build up your endurance and gain lean muscle mass.

How Does It Work?

Healthy dish on a plate

The key to intermittent fasting is that it changes when your body is in a fed state and a fasted state.

Your body acts differently depending on which state it is in.

Fed State - After you eat a big meal, your body is in the fed state for 3 to 5 hours while it digests and absorbs all the nutrients it can get from your food.

This means it won't be turning to its fat stores for energy, especially if you've eaten lots of carbohydrates and starches that raise your insulin level.

It takes our bodies almost 12 hours to enter the fat-burning fasted state.

Fasted state - After your food is digested, your body goes into a post-absorptive state that lasts between 8 and 12 hours after eating. When food is absent, the body's levels of blood glucose go down significantly. This lowers the amount of insulin that is available, which causes your body to burn through its fat reserves for fuel instead.

Working out in a fasting state is especially beneficial for your body. When you exercise at a time when your body can't draw from its glucose stores, it is forced to adapt and use the other source of energy that's available - your body fat.

Reasons to Consider Intermittent Fasting

Woman eating her lunch with a fork

Maybe you've been trying to lose weight for months without seeing much result.

Perhaps the last few pounds are proving to be the most difficult to dislodge.

If this sounds like you, your eating habits could be benefited from trying intermittent fasting.

Below are some of the reasons why intermittent dieting might be the right diet plan for you.

1. It's Not A Diet, It's A Method Of Eating - Regular diets like Weight Watchers or Atkins can be a pain to live with on a daily basis as you have to count calories and avoid certain foods. While diets like Calisthenics might not count calories, you still need to avoid certain foods. With IF, you just change when you eat allowing for more flexibility throughout the day. Most diets fail because it is difficult to stick to them in the long term as you have to give up your favorite foods unlike IF.

2. Your Workouts Might Become More Effective - It may seem counter-intuitive, but working out on an empty stomach may actually make your workouts more effective. Exercising on an empty stomach supercharges your bodies fat-burning abilities, allowing you to shed more weight in less time.

3. Your Eating Plans Become Simpler - Intermittent fasting allows you to make big changes to your body's fuel efficiency with only minimal changes of behavior. You will have fewer meals per week to worry about, and you rarely need to calculate what goes into each meal. By eating fewer meals, you'll be doing less cooking and consequently do less grocery shopping. Saving the time each day that would normally be spent preparing and eating food can add up over time.

4. You Can Stave Off Emotional Eating - If the restrictive nature of most diets causes you to binge on cheat days, IF might be a good diet plan for you. Studies have shown that when people followed an IF diet combined with exercise, they decreased their levels of emotional eating and were less likely to make harmful food choices.

5. You Just Might Live Longer - It's been known for decades that restricting calories can help you live longer, and IF makes eating less easy and painless. It activates the same mechanisms for extending your life as restricting your calories, all without the benefit of feeling like you have to deprive yourself.

You can also watch this interview with Joe Rogan where they tackled about the reasons why you should do intermittent fasting.

Intermittent Fasting Methods


Starting an intermittent fast is easier than most people think. Simply cut out some of the times that you eat food and experiment until you find what feels right for your body.

Some people do better with a small breakfast at the beginning of the day, while others are able to skip food entirely until the afternoon. The key is to try different methods until you find what your body responds best to.

There are several types of intermittent fasts, all that rely on different intervals of time between eating and fasting. Six of the most popular diet plans are explained below.

1. 16:8 (Lean Gains)

A snapshot of a before and after doing Lean Gains, taken from Youtube.

As one of the most popular fasting methods for beginners, the Lean Gains method was created by Martin Berkhan as a way to make fasting both convenient and habitual.

The premise behind this diet plan is simple; dieters don't eat anything for 16 hours and then eat within an eight hour eating window - sometimes referred to as 16/8 fasting.

Most people eat their last meal of the day around 8pm and then fast through the night and morning until 1pm. For maximum fat-burning benefit, some people choose to workout around 11am or noon.

  • This diet plan is simple to follow and requires minimal lifestyle changes. It also gives you the flexibility to eat as much as you want during the eating periods.
  • If you're working out frequently, the dietary requirements are much stricter. Many people also find it difficult to work out at the end of 16 hour fast, which might make it easier for you to skip your workouts.

2. 24 Hour-Fasts (Eat-Stop-Eat)


The Eat-Stop-Eat fast was created by Brad Pilon and is ideal for healthy eaters looking to get an extra boost out of their diet.

The premise is that followers of the plan go on 24 hour fasts for one or fewer days every week. Some practitioners fast as just a few times a month.

Surprisingly enough, even occasional fasts like this has been shown to lead to the health benefits.

The idea is that by cutting out a day of eating every once in a while, you will be restricting your overall calorie levels, even if your daily eating habits remain unchanged.

  • The Eat-Stop-Eat plan is flexible and allows you to try out fasting without committing to a daily routine. You can also work your way up to 24 hours over time and start with a time that is more comfortable for your body. No calorie counting or meal-time planning is required.
  • Some people find it hard to go 24 hours without food, and attempting to fast makes them cranky, anxious, foggy-headed and prone to headaches. (These side effects diminish the more you practice fasting). You need lots of self control to follow through with this diet plan.

3. Alternate Day IF (Up Day, Down Day)


Created by Doctor James Johnson, the Up Day Down Day fasting program is all about weight loss and is structured to cause you to lose as much weight as possible in a healthy way.

The idea is that alternating the amount of calories you eat everyday activates the SIRT1 gene, which helps prevent your body from putting fat into long term storage.

This meal plan is simple to follow. You alternate each day from eating a normal diet to eating one fifth of the calories you ate the day before. For most men, this means they eat 2,500 and 500 calories every other day, and for women the levels are 2,000 and 400.

  • When followed correctly, this meal plan makes it easy to lose weight. The participants in Dr. Johnson's study averaged 2.5 pounds of weight loss every week they followed the fast.
  • Some people find it troublesome to monitor their calorie counts everyday, and it can be easy to overeat on your regular eating days.

4. 20:4 (The Warrior Diet)


The Warrior Diet, started by Ori Hofmekler, combines a 20 hour fast with a 4 hour eating window for eating.

The long fast increases the functionality of the sympathetic n system (responsible for fight-or-flight tendencies) in order to stimulate lipolysis and increase the metabolic rate of fat burning.

This helps the body to absorb glucose properly and recover more efficiently after a big workout, while also increasing your alertness and boosting your energy levels.

  • The “fasting periods” in the Warrior Diet still allow you to eat food, and when followed properly with strength training exercise, you are likely to bulk up.
  • Eating one monster meal a day can be hard logistically during social gatherings, and the guidelines about what can be eaten are hard for some people to follow long term.

5. 5:2 Fast

meat and veggie plate

Popularized by the British doctor Michael Mosley, the 5:2 diet allows you to eat normally for five days out of the week, and to eat only 500-600 calories on two non consecutive days.

There are no eating requirements besides counting calories two days a week, and you have complete control over which days those will be.

Many people chose to fast Monday and Thursday and eat regularly for the rest of the week.

  • This plan is easy to follow, has minimal instructions, and allows you to eat whatever you want five days out of the week. There also aren't any times when food is completely restricted, making it an easier eating plan to fit into your social life.
  • This meal plan can be so similar to regular eating that some people won't notice any positive health effects from trying it.

6. 36-Hour Fasts (Fat Loss Forever)

meat and veggie plate

By far the most complex plan to follow, Fat Loss Forever starts you off with one cheat day every week, which is followed by a 36 hour fast.

The rest of the week is split into varying intervals of fasting and eating periods.

Romaniello and Go (founders of the diet) recommend that your longest fasts take place on your busiest days, and that you keep yourself busy and productive to keep your mind off your hunger.

When combined with strength training, this plan will bring your to your ideal weight in a very efficient way.

  • Because you will be fasting almost every day, your body gets the maximum benefits from the process, all while getting to enjoy a cheat day.
  • Some people take their cheat day too far and have difficultly losing weight long term. This meal plan is also very specific about when you can and can't eat, making it confusing to follow at first.

What Are The Benefits?

Regulating your eating through fasting can have lots of health benefits for both your brain and body. Not only can it cause weight loss, it can also help protect you against inflammation and cancer.

Increased Weight Loss - A 2014 study found that a weekly fasting practice led to 3%-8% weight loss in participants after several months. Those same participants saw their waist size shrink 4-7%, meaning belly fat was the main type of weight they were losing. The diet also found to do a good job of lowering insulin levels and improving the body's ability to process insulin quickly [1].

Cancer - There hasn't been enough research on the benefits of fasting for cancer for the results to be conclusive, but the early results have been promising. A study of 10 cancer patients revealed that the harmful effects of chemotherapy could be reduced when patients fasted before getting treatment, while a separate study found that alternate day fasting during treatment led to better cure rates for patients [2] [3].

Reduced Inflammation - Chronic inflammation is the precursor to a variety of horrible long term health conditions like arthritis and heart disease. Thankfully, fasting seems to provide some benefit. Going through periods of fasting can trigger damage-repairing adaptions into your cells, which breaks down inflammation at its beginning. Numerous studies have shown that regular fasting can reduce the overall amount of inflammation you experience, which helps to lower your risk of developing a disease [4].

Is Intermittent Fasting Safe?

At this point, you may be thinking that fasting looks like a miracle diet cure for everyone. Though the evidence can be compelling, that's not quite true.

Women in a row

Women - There is some evidence that IF might not be a beneficial for women as it is for men. Some studies have shown that while IF can improve insulin sensitivity levels for men, it can actually have the opposite effect for women and worsen their control of their blood sugar levels [5].

Regular fasting often stops a woman's period, though it usually comes right back when they stop fasting.

Pregnant women

Pregnant women - The practice can also be damaging for women that are trying to get pregnant, are already pregnant, or who are breastfeeding. If you are female, the best way for you to start intermittent fasting is to ease into it.

Start for a few hours at a time and up the amount weekly if you continue to feel good. If you start to notice negative side effects from fasting, you should stop the practice right away.

Insulin injections

Diabetics - There are also medical conditions that can make fasting a bad idea.

If you have diabetes or need to regulate your blood sugar, it's not a good idea to force your body to go for hours without food.

Like what most always say, it's better to be safe than sorry.

Scale with an apple on it

History with eating disorders/underweight - If you are prone to eating disorders or are already close to being underweight, fasting won't give you much benefit and might even trigger to you start an eating disorder.

All this to say, intermittent fasting is a safe and effective dieting method for a huge number of people. If you are healthy and well nourished overall, you shouldn't have any problems.

How to Get Started

Many people start off with the 16:8 method where you eat within a 8 hour window. It's the most simplest and sustainable way of intermittent fasting.

If this gets too easy you can then move on to 24 hour fasts or other methods mentioned before.

When you first start fasting, it's more than likely you will experience feelings of overwhelming hunger and feel weaker and slower than usual. This is completely normal and part of your body's adjustment period. Your feelings of hunger should fade within a few fasting sessions as you get used to occasional hunger pangs.

For the first few times, you can even have a small snack handy just in case you need to revive yourself.

However, if you feel ill or faint every time you start to fast, something bigger might be going on and you should grab something to eat and talk to your doctor right away. Fasting isn't for everyone, and some bodies respond differently than others.

Some people truly do need to eat three big meals everyday, and that's perfectly fine. The best thing you can do is listen to your body and adjust your fasting plans according to what it responds best to.

Tips for Your First Fast

Ready to give fasting a try? Here are some tips to keep in mind

  • Drink lots of water: Being dehydrated makes every fast more difficult to get through, so keep a water bottle by your side where ever you go.
  • Fast overnight: By keeping your longest fasts during the night, you allow yourself to sleep through eight hours of it, which makes the process much easier mentally.
  • Go all in: At least with your schedule, that is. By keeping yourself busy you don't have time to think about your hunger.
  • Go for a workout: Working out during your fast helps you to burn fat faster, which makes your fasting plan even more effective for weight loss.


What Happens if I train on a Fast?

Intermittent fasting can have positive effects on your exercise and strength training regimes. Training while fasting can lead to better metabolic efficiency (which leads to better performance) and a higher anabolic response when you eat after exercise.

This means your body will be revved up to burn through fat more quickly [6].

When you work out while you fast, you burn more fat during the workout. Some studies even showed that IF caused 20% more fat to be burned during workouts.

Does intermittent fasting break down muscle?

The human body is an expert at preserving muscle mass while fasting and protein absorption takes hours to complete.

Though muscle loss will eventually start to occur from fasting, it won't start until you have been doing it 72-96 hours, far longer than most people want to give up food! [7] [8]

Can I take supplements while fasting?

Yes, you can take supplements while fasting. Pay attention to whether your supplements can be taken on an empty stomach.

Most vitamins are recommended to be eaten with food, because the side effects of eating them on an empty stomach include nausea, diarrhea and stomach pain.

Keep yourself feeling comfortable by reading the bottle first and adjusting your consumption accordingly.

Related Post: Should you take BCAAs while fasting?

The Bottom Line on Intermittent Fasting

When followed properly, intermittent fasting, along with portion control, can be a great weight loss strategy for almost anyone.

If you are tired from following traditional diets and want to make a change to lose those last few pounds,

intermittent dieting can be a way to become healthier, lighter, less prone to disease, and even more muscular and physically fit.

Take the time to try out different methods and intervals of dieting, and you will soon be enjoying the benefits of this simplified eating strategy that have been helping people to live longer, healthier lives for thousands of years.

Have you had experience with intermittent fasting? What was your impression of it?

We want to hear from you!


  1. Adrienne R. Barnosky, Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Retrieved from
  2. Fernando M. Safdie, Fasting and cancer treatment in humans: A case series report. Retrieved from
  3. Johnson JB, Pretreatment with alternate day modified fast will permit higher dose and frequency of cancer chemotherapy and better cure rates. Retrieved from
  4. Faris MA, ntermittent fasting during Ramadan attenuates proinflammatory cytokines and immune cells in healthy subjects. Retrieved from
  5. Heilbronn LK, Glucose tolerance and skeletal muscle gene expression in response to alternate day fasting. Retrieved from
  6. Deldicque L, Increased p70s6k phosphorylation during intake of a protein-carbohydrate drink following resistance exercise in the fasted state. Retrieved from
  7. Soeters MR, Intermittent fasting does not affect whole-body glucose, lipid, or protein metabolism.Retrieved from
  8. Nair KS, Leucine, glucose, and energy metabolism after 3 days of fasting in healthy human subjects. Retrieved from
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2 thoughts on “Intermittent Fasting Beginner’s Guide
Everything You Need to Know

  1. I am definitely going to start the intermittent diet. I will send my before and after pictures.

  2. Thanks for this. Since the benefits of intermittent fasting look promising, I’ll try this out. I hope it will make me lose weight fast!

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