Intermittent Fasting to Lose Weight: The Ultimate Guide

Intermittent Fasting to Lose Weight: The Ultimate Guide

Intermittent fasting is one of the most popular ways to lose weight right now. Here is all you need to know about intermittent fasting, and how to lose weight with intermittent fasting.


  1. What is the Intermittent Fasting diet?
  2. Intermittent Fasting types
  3. How to do Intermittent Fasting?
  4. Does Intermittent Fasting really help with weight loss?
  5. Health benefits of Intermittent Fasting
  6. Intermittent Fasting for women
  7. How does Intermittent Fasting work?
  8. Intermittent Fasting meal plans
  9. Side effects of Intermittent Fasting
  10. Benefits of tracking your fast

What is the Intermittent Fasting diet?

Intermittent Fasting diet is not exactly a diet with a certain food list, rather it is about scheduling your meal times.

When doing Intermittent Fasting, you basically fast for a specific period, which means you don’t consume any food during that time (except for some allowed beverages) and you can eat during the remaining hours of the day. This period is called the “eating window”. This “eat and fast” cycle repeats on a regular schedule.

The best part is that Intermittent Fasting mainly focuses on when you have your meals, rather than what you have for your meals. That’s why it is becoming another new trend in the decline of the diet culture.

Fasting for long periods boosts metabolism and weight loss. It promotes weight loss without restricting you in terms of which foods you can and can’t eat.

Fasting and Eating Windows

While the popularity of Intermittent Fasting is increasing globally, famous celebrities got great results with intermittent fasting. It has been practiced for many years by world-famous Hollywood celebrities such as Miranda Kerr, Nicole Kidman, Beyonce, Benedict Cumberbatch, Jennifer Anniston, Halle Berry, Kourtney Kardashian, and Hugh Jackman, for its countless benefits including lasting weight loss and weight management.

It’s a popular method not only in Hollywood but in the business world. We know that businessmen like Twitter’s former CEO Jack Dorsey and Tesla CEO Elon Musk are big fans of fasting for a fitter body and mind. 

Why is everybody so crazy about Intermittent Fasting?

Typical diet plans are hard to follow and they can complicate your everyday life, with lots of snacks to eat between main meals. By switching to an Intermittent Fasting nutrition system, you will:

  • Gain a simplified nutrition regime,
  • Save time,
  • Avoid food restrictions,
  • Be able to follow your fasting plan wherever you are.

Intermittent fasting eating period

There are various methods of Intermittent Fasting to suit every individual’s needs and lifestyles. The most popular one is 16:8 Intermittent Fasting, which is also called the 16:8 diet or 16:8 plan. You fast for 16 hours and eat whatever you want during the 8-hour eating window.

Other popular fasting plans include:

Every individual’s physiology and needs are unique. You can see the fasting types in detail below, so you can choose the one that best suits your needs.

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Intermittent Fasting Types 

There are several ways of doing intermittent fasting, based on the patterns of when you eat and when you fast:

Intermittent Fasting Types

1) 12-hour fasting

12-hour fasting is also known as circadian rhythm fasting or the circadian rhythm diet. It simply encourages you to eat in line with your body’s internal clock.

A typical circadian rhythm diet includes a 12-hour fasting period between dinner in the evening and breakfast the next day. The important point is that you should arrange your meal times during daylight hours. This is an easy-to-follow schedule that still offers the weight loss benefits from intermittent fasting. So this is a perfect method for those who are new in fasting and for early birds who can’t skip breakfast.

2) 14/10 fasting: 

Another convenient version of fasting, the 14/10 fasting schedule includes 14 hours of fasting and 10 hours during which you can eat. But there’s no doubt that it’s effective. Fasting for 14  hours a day improves your cardiovascular health and helps you lose weight.

In particular, experts recommend a 14/10 method for women as a starting point, since a longer fasting period can cause irregular menstrual cycles (1). Note that fasting according to the menstrual cycle is the best method for women that are of child-bearing ages.

3) 16/8 fasting: 

The 16/8 fasting plan is the most popular regimen among lovers of fasting, and one where you restrict your eating window to 8 hours. Compared to 14/10, 16/8 is more intense and offers more efficient results for those aiming to lose weight.

Studies show that people who implement a 16/8 fasting schedule obtain weight loss (2) benefits and burn fat (3) while preserving muscle mass.

4) 20/4 (The warrior diet): 

The warrior diet (also called 20/4 fasting) is a real challenge, with an eating window that’s only 4 hours long. An extended fasting period results in significant fat burn and weight loss. In a study conducted with people consuming one meal a day, participants lost weight (4) and gained muscle at the same time.

In addition, compared to 16/8, 20/4 fasting plans boost greater autophagy – a process providing regeneration of healthier and functional cells. But keep in mind that this is an extreme version of fasting and it may be difficult to stick with if you’re a social butterfly participating in social activities like brunch or lunch.

5) Alternate day fasting (ADF): 

Alternate day fasting (ADF) is an advanced intermittent fasting approach, based on a simple idea: eating every other day. You fast for 36 hours and eat whatever you want during the following 12 hours.

There is some evidence that it may help weight loss (5), but some studies have not found any difference between ADF and a normal calorie restricted diet (6, 7).

6) 5/2 fasting: 

5/2 fasting is an easier version of ADF. With this schedule, you eat according to your normal routine for 5 days in a week and consume only 500-600 calories on the remaining two days. This schedule has various proven health benefits, ranging from weight loss (8) to breast cancer protection (9), and decreased insulin resistance (10).

7) Eat-Stop-Eat: 

Another popular and convenient form of intermittent fasting, the eat-stop-eat diet includes fasting once or twice a week. Although there is no direct evidence that this method is effective for weight loss, prolonged fasting may increase your metabolism (11) and thus contribute to weight loss.

There is no one “ideal” method to get efficient benefits from fasting. You’re a unique individual with a unique body, so find your best fit by switching between different fasting types. Or simply get Fasting Kompanion to get a customized fasting plan through a detailed analysis of your personal goals and body needs.

How to do Intermittent Fasting?

Intermittent fasting has a simple logic. Basically, you fast for a certain period of a day and eat in the remaining time.

According to Dr. Berg, an expert in intermittent fasting and ketogenic diets, the right way to do intermittent fasting involves gradual progress.

If you’re eating 5 meals a day, a sudden decrease to 2 meals a day won’t lead to sustainable change that will help you lose weight. Instead, Dr. Berg recommends switching to 3 meals a day without setting any time restriction and once you get used to that, limiting the time during which you eat.

If you want to burn more fat, you can then expand your fasting time, having 2 meals a day.

Does Intermittent Fasting really help with weight loss?

There are many benefits of intermittent fasting. Weight loss is one of them, and that’s why there’s an increasing interest in this nutrition system.

According to the  Harvard School of Public Health’s systematic review of 40 studies, intermittent fasting promotes 7-11 pounds (3-5 kg) of weight loss over 10 weeks. (12)

If you’re wondering if intermittent fasting helps you lose weight, let’s dive deeper into the subject and find out how intermittent fasting is a powerful tool for lasting weight loss:

  • You eat fewer calories

First of all, the main reason intermittent fasting works for weight loss is that it helps you eat fewer calories.

A study showed fasting plans restricting calorie intake during the night hours significantly boost metabolism and weight loss. (13) And the best bit is that you mostly preserve muscle mass if you combine IF with light cardio exercises such as brisk walking.

16/8 method, 18:6 plan, warrior diet  (20:4) or any other time-restricted feeding plan… They all have one important thing in common, which is skipping meals during the fasting periods. This naturally leads to consuming fewer calories in total, which is an easier way than counting calories in traditional diets.

  • Your body uses its fat storage for fuel

During the fasted state your body first uses its glycogen stores (stored carbohydrates) as a fuel.

As the glycogen level drops, the excess fat in your body will be the main source of fuel. For instance, if you’re suffering from belly fat, you’ll get rid of the excess fat in that area as you integrate intermittent fasting diet into your lifestyle.

  • Your hormones inhibit your hunger

As your body gets used to fasting in time, you secrete leptin (the satiety hormone) faster and you feel fuller with smaller portions.

Since fasting reduces ghrelin (the hunger hormone), you feel less hungry than usual during your fasting hours. Late night cravings diminish and you won’t find yourself looking for something to eat.

Health benefits of Intermittent Fasting

Is it safe/healthy to fast? If safe/healthy, what are the most important health benefits of fasting? These are the most frequently asked questions by fasting beginners.

Although studies into intermittent fasting and its effectiveness are ongoing, thanks to the research carried out so far, we already know that it has many benefits for the mind and body.

Following a fasting plan is a great tool for weight loss and weight control. Some studies show that it can prevent some diseases and even reverse existing ones.

Dr. Jason Fung, a nephrologist, is a health professional who has been studying the link between nutrition and diseases like obesity and type 2 diabetes — both precursors to kidney disease. He utilizes fasting for the treatment of metabolic diseases.

Here are the most popular benefits as you start following an intermittent fasting plan:

  1. Insulin level drops (recommended for patients with type 2 diabetes)
  2. Blood sugar is balanced
  3. Autophagy of the cells (detoxing the old and damaged components of the body) is activated
  4. Heart health improves
  5. Inflammation reduces
  6. Digestion and microbiome diversity improves
  7. Brain health improves (decreased risk of Alzheimer’s, reduced brain fog symptoms etc.)
  8. Mood and energy levels increase

Intermittent Fasting for Women

Clearly, there are important differences between male and female bodies.

Just as the caloric needs of men and women are different (even for the same daily activity level), their body’s response to intermittent fasting is different, too.

Women’s physiology is more sensitive to calorie restriction than men’s. But many women have experienced great benefits by integrating suitable intermittent fasting plans into their daily life.

Lasting weight loss is just one of these benefits of intermittent fasting. Reduction of belly fat, improved cardiovascular heart health (14), improved digestion (15), and a brighter and younger-looking skin are just a few of them.

So if you’re interested in a complete detox of the old and damaged components in your body for a slimmer and healthier-looking figure, intermittent fasting may be the key by supporting autophagy – a cellular renewal process in which your body removes the old cells to make room for new ones. (16)

However, you should keep in mind that fasting plans with very narrow eating windows may cause hormonal imbalances in some women.

It’s better for women to follow personalized fasting plans according to their menstrual cycles to get the best results out of intermittent fasting and avoid interfering with their hormones.

Starting with a circadian rhythm diet by fasting for 12 hours and having a 12-hour eating window may be ideal for most women.

​​As the body gets used to this system, the fasting window can be increased to 14 hours. With a 14:10 fasting plan, a woman can experience all the benefits of intermittent fasting for weight loss, including the fat-burning stage. To find out more information on intermittent fasting for women, check out our detailed article.

If fasting every day is straining the body, fasting on non-consecutive days of the week can be another method, which is similar to alternate-day fasting (ADF).
You should avoid following an intermittent fasting plan if you:

  • are pregnant
  • are breastfeeding
  • are underweight
  • have experienced/are experiencing body dysmorphia
  • have excessive levels of stress in your life

If you don’t fit in any of these categories, give intermittent fasting a try for lasting weight loss and many more benefits.

You can get Fasting Kompanion to follow the best fasting plan that suits you.

How does Intermittent Fasting work?

With its endless list of health benefits, intermittent fasting sounds like a miracle. Is it just a new health myth or does it really work?

A lot of research has been conducted to reveal the actual mechanism behind intermittent fasting, and scientists have discovered that the human body goes through a variety of stages during fasting, activating different mechanisms that lead to a number of perks.

Here are the stages that your body goes through while fasting:

Intermittent Fasting Stages

1) Anabolic stage (0-4 hours)

The anabolic stage (also called the feeding state) involves the first few hours after having your last meal. In this stage of fasting, your body is busy with digestion and absorption from the nutrients that provide energy in your food.

2) Catabolic stage (4-18 hours)

During the catabolic or early fasting phase, the digestive process finishes and your insulin level falls. This is beneficial in breaking down insulin resistance, where your pancreas pumps out excessive levels of insulin.

This is also the favorite part of those targeting weight loss. Your body begins to use the glycogen stores in your liver, so you burn stored body fat.

When your insulin level decreases, growth hormone is released in your blood. This is a powerful fat burning hormone that preserves your muscle mass and helps burn actual fat.

If you combine fasting with the ketogenic diet (a diet that includes low carb and high fat/protein), your body enters ketosis in this phase – in other words, you use ketones for energy. This leads to increased fat burn, and gives you a positive mood and mental clarity.

Most common fasting methods like 16/8 include the early fasting state.

3) Ketosis (18-36 hours)

In the ketosis stage, your body uses stored fat as its main source of energy since not enough glucose is available. To obtain  energy, your liver produces ketone bodies. During this stage, your appetite is pretty much gone and your brain cells are renewed.

4) Autophagy (24-48 hours)

This is the period where you go into a serious autophagy – a cellular rejuvenation process. Think of it as a vacuum cleaner, a mechanism that clears old and dead cells to replace them with new and healthy cells. In other words, your body decides what is necessary and what is going to be rebuilt.

Intermittent Fasting Meal Plans:

Intermittent fasting puts emphasis on when you eat, but what you eat still matters. So schedule your meals to make sure you take in enough nutrients from leafy greens, whole carbs, healthy fats, and proteins.

1) A perfect beginner-friendly plan (12/12, 14/10)

An eating window between 8 a.m. and 6 p.m. provides a warm welcome when you decide to say hello to fasting land. An example plan can involve 3 main meals:

  • Breakfast (8 a.m.)
  • Lunch (12 p.m.)
  • Snack (3 p.m.) – optional
  • Dinner (6 p.m.)

2) Intermediate fasting meal plan (16/8, 18/6)

If you get used to the cold of the fasting sea, you can schedule an eating window including two big meals and a snack, starting at 11 a.m. and ending at 7 p.m. Here is an example meal schedule:

  • Breakfast (11 a.m.)
  • Snack (3 p.m.)
  • Dinner (7 p.m.)

3) Alternate-day fasting

Long name, short plan. You just organize a plan that means you eat every other day. Filling your plate with nutritious foods is the key to doing this fasting type correctly. A sample meal plan includes:

  • Monday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Tuesday: Fast.
  • Wednesday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Thursday: Fast.
  • Friday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Saturday: Fast.
  • Sunday: Protein, healthy fats, whole carbs, vegetables and fruit.

4) 5-2 meal plan

In this plan you can pick 5 days on which you eat whatever you want (we encourage you to choose healthy options) and restrict your calorie intake to less than 500-600 on the other two days. An example 5-2 meal plan is:

  • Monday: Low calorie day
  • Tuesday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Wednesday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Thursday: Low calorie day
  • Friday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Saturday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Sunday: Protein, healthy fats, whole carbs, vegetables and fruit.

5) Eat-Stop-Eat meal plan

First, you choose 1-2 days of the week to fast. You simply consume zero calories on those days and eat normally on the remaining days. Again, make sure that you are consuming healthy fats, enough protein, fruits and vegetables. A sample meal plan looks like this:

  • Monday: Fast
  • Tuesday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Wednesday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Thursday: Fast
  • Friday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Saturday: Protein, healthy fats, whole carbs, vegetables and fruit.
  • Sunday: Protein, healthy fats, whole carbs, vegetables and fruit.

Of course, intermittent fasting is a flexible plan so you can arrange your meal times in line with your daily routines. We just want to provide you a baseline to make clear how to schedule your meals during intermittent fasting.

Here’s a detailed 7-day intermittent fasting diet meal plan to set you an example.

Side effects of Intermittent Fasting

In the first few weeks of switching to intermittent fasting, having some side effects is completely normal. The most common problems are:

  • Hunger:

Leaving your old habit of having 3 meals a day and multiple snacks in between meals is hard in the beginning. New habits take time to settle.

You will feel less hungry as time goes on. Just be patient and drink herbal teas during your fasting hours to make you feel fuller.

  • Headaches:

Being hungry for a long period or not drinking enough water during the fasted state may cause headaches in some people.

If the problem persists for too long, switching to a gentler fasting plan with a longer eating window may eliminate this side effect.

  • Constipation:

Constipation may be caused by dehydration. Make sure you don’t skip drinking enough water during your fasting hours.

  • Mood changes:

Eating is a coping mechanism for some people in times of difficulty. Your body needs some time to adjust to a lifestyle where snacking is not allowed all the time.

  • Low energy:

Feeling tired because of hunger is normal in the first few weeks.

Drinking black coffee/black tea or green tea will help you recharge your batteries as they all contain caffeine.

Remember not to add any sugar, creamer or other additives to your beverage during your fasting period.

  • Bad breath:

Not eating for hours may sometimes cause bad breath. Drinking black or green tea helps with this problem.

  • Sleep disturbances:

Having a snack late at night is not permitted when doing intermittent fasting, as one of the main features of fasting is to eat in harmony with daylight.

So if you’re a big fan of sneaking into the kitchen and snacking at a late hour, you may experience sleep disturbances, as you may feel hungry while trying to sleep.

You can help yourself with this by drinking herbal teas that promote better sleep such as chamomile, valerian root, lavender, lemon balm, and passionflower.

These side effects are acceptable in the first few weeks. If they persist, switch to a different intermittent fasting plan after consulting your doctor. If your problem with sleep persists, simple tips to deal with insomnia may help.

Other than these problems, there is a suitable plan for almost everyone, unless you;

  • are pregnant or breastfeeding,
  • are using insulin medicines,
  • have type 1 diabetes,
  • have low blood pressure,
  • have low blood sugar level (hypoglycemia),
  • have other serious chronic diseases that are under treatment,
  • have eating disorders or body dysmorphia.

If you are over 18 and do not fall into any of these categories, you will experience great benefits from intermittent fasting.

If you have any hesitations about switching to this “fast and feast” cycle, consult a medical professional in advance.

Benefits of tracking your fast 

When it comes to achieving your goals with long-lasting results, tracking your progress is key.

Reminding you about when you should start and end a fast is just one small part of Fasting Kompanion’s tasks.

Creating graphs and charts to make it easier to track weight changes has a big impact on your commitment to fasting. The higher the commitment to your fasting plan, the higher the motivation to achieve your goals.

All the questions that might spring to mind are also answered by the blog articles that are offered to suit your moods and other personal needs.

Kompanion becomes a personal cheerleader to help you along on your unique journey to a healthier life.

In summary, Fasting Kompanion offers:

  • Timer for fast start/end times
  • Tracking of your fasting progress
  • Weight tracker and statistics with graphs
  • Tracking of your moods at the end of fasts
  • Integration with other health apps like Apple Health and Google Fit
  • Notification alerts and no advertisements
  • Visualization about what happens in your body during fasting
  • Visualization of your fasting history
  • The chance to stop, restart, or adjust the fast at any time
  • Customized blog articles to keep you informed and motivated

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