How to Lose Belly Fat Fast | The Definitive Guide (2020)

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  1. How does the body lose fat?
  2. What’s the next step once you’ve worked out your TDEE?
  3. How do you burn fat healthily?
  4. What is the healthy rate of weight loss?
  5. Protein, fats, and carbs – creating a caloric deficit
  6. Do you need cardio for fat loss?
  7. HIIT vs. Normal cardio
  8. Does the body fat percentage matter?
  9. Summary of points to remember

When it comes to losing that excess body fat fast, many people undertake extreme approaches to dieting and exercising with expectations for quick results.

The undesired excess fat does not just look bad for most people, but in the long run it can lead to issues, such as heart disease.

Now, before you learn how everything works, you need to remember this valuable insight:

The body is a complex biological machine, which does NOT like drastic changes.

In other words, if you go crazy on your diet and lose, say, 10 kilograms in a month, the body will adapt in a way that will eventually lead to 100% or more weight regain in TWICE AS LESS time.

You can’t outsmart your body and you can’t sustain an aggressive diet for a long time.

Well, maybe you can, but that will be at the cost of mental and physical performance.

For this article, you’ll get the EXACT approach to sustainable, quick weight loss, which is based on proven principles.

First and foremost, let’s see what fat is, why the body accumulates it and how it can be lost.

How does the body lose body fat?

The body is a complex biological machine, in which, you have a flurry of physiological processes occurring all the time.

Every living organism on planet Earth requires a certain amount of energy to sustain those processes and weight in space.

For humans, that energy is derived from food and is measured in calories.

That is to say that your body requires a certain amount of food DAILY to maintain weight and proper functioning, as well as fuel for physical and mental activities.

This daily amount of energy (number of calories) is known as the “Total daily energy expenditure (TDEE)” and depends on a variety of factors:

  • Basal metabolic rate (BMR, the number of calories required to maintain weight and functions AT REST)
  • Gender
  • Age
  • Height
  • Weight
  • Non-exercise activity (NEAT)
  • Exercise output
  • Thermic effect of food (The amount of energy your body burns during digestion)

Now, for each of these variables, there is a mathematical formula.

However, instead of working out the math for yourself, you will be able to use this trusted calculator which has all the formulas integrated.

If you’re following the logic so far, you’d know that each and every one of you has your own individual body needs, which is why there is no unified diet plan for fat loss.

However, calculating your TDEE is the first and most important step toward your goal of weight loss.

What’s the next step once you’ve worked out your TDEE?

total daily energy expenditure for losing fat

After you know how much energy you need to MAINTAIN your body weight daily, there’s just some simple math that you have to do.

If you consume LESS than your TDEE (Being in a calorie deficit), you will allow your body to tap into its fat storage, which the body burns during a deficit.

And on the other hand, if you consume MORE than your TDEE (extra calories), that will lead to weight gain.

Why? Because the body won’t allow unused energy to go to waste and will make sure to store it for later.

As human beings, that storage is the ugly fat you may have had at one point or another.

Calories in vs calories out

Calories in vs calories out is the MAIN factor for weight loss.

People get fat and/or obese because they consistently consume a greater amount of food than their bodies require to maintain weight and proper functioning.

“What about hormones? I don’t care about calories, I have hormonal issues!”

Well… Guess what regulates the endocrine (hormonal) system…?

That’s right, your eating and exercising habits!

Not only that but exercising will also help you burn calories which is part of the big picture.

How to burn fat healthily

Okay, you now know that the primary determinant for the changes in your weight is your energy input & output.

Again, an input greater than the output will lead to gain and an output greater than input will lead to fat loss.

Following this logic, you could say that the more you restrict the body of food, the better it is for weight loss, right?

Well, not really.

You need to acknowledge the fact that when losing fat, you’re in a form of “controlled starvation”.

With this controlled starvation, many changes, such as a slowdown of the metabolic rate occur.

When you’re in a caloric deficit, required to burn body fat, you’ll not only lose fat tissue, but also lean body mass (LBM) and furthermore, the metabolism slows down to preserve energy.

Note that lean body mass is not just muscle mass, but rather every other tissue in the body except for fat.

That is to say, you need to give the body enough energy for sustained healthy functioning, LBM retention, as well as physical and mental activities.

If you go aggressive on a diet, you will lose lean body mass and eventually reach a physical and mental burnout, due to the enormous deficit of energy.

Not only that, but when you get back to eating more food sooner or later, you will gain all the fat (if not more) back in less time than it took you to lose it.

What is the healthy rate of weight loss?

The optimal rate of weight loss depends on your starting point.

Generally for non-obese individuals, the optimal rate of weight loss, that will optimize LBM retention and healthy functioning, forms at 0.5-1 kg per WEEK.

Such a rate of weight loss can be achieved at a caloric deficit of about ~500 calories DAILY.

Individuals who have substantially more body fat and/or are obese can lose up to 2-3 kg weekly in the initial phase.

However, for those people, decreasing the deficit is required, as they get back to a normal body composition.

Protein, fats, and carbs – creating a caloric deficit

image of four different foods high in protein and fat. These include almonds, avocado, salmon, and an egg

All weight loss requires is a sustainable caloric deficit, which will allow the body to tap into its energy reserves and sustain healthy functioning of daily activities.

Now, though this is the first and most important thing, there is another determinant when it comes to body composition & hormonal balance.

That is namely your protein & fat intake.

Let’s take a closer look.


The word “Protein” itself is derived from the Greek “Protos”, meaning “Primary/first”.

Your entire body is made up of different proteins, which is exactly why your protein intake is one of the primary determinants for successful lean body mass retention.

Not only that, but protein is also involved in a vast variety of physiological processes.

This is why you MUST grant a relatively high-protein diet to the body, given that you want to lose fat and retain lean body mass.

Optimal protein intake for muscle retention in low-calorie conditions forms at the broad range of 1.5-2.5 grams per kilogram of body weight, per DAY.

Note that the more trained you are and the more lean muscle mass you have, the more protein you will require to maintain it.

That is to say, if you’re just starting on your training and don’t have much muscle whatsoever, 1.5 grams of protein per kilogram of body weight daily will do the job.

If however, you’ve been doing resistance training for some time and now have more muscle, you’d have to be on the upper range of that spectre, to maintain your muscle.


Protein & fats are the two ESSENTIAL macronutrients for the body.

In other words, if you severely deplete your body of those two, you will not only experience loss of muscle mass & energy, but also hormonal disbalances.

A low-fat diet is not recommended, as it will lead to disbalances of many types. Some studies have shown hormonal changes in individuals who were severely depleted of fat

Ultimately, fat should make up about 20% of your daily energy intake and you should make foods like red meats, avocados & olive oil, your preferred source of dietary fat.

The optimal fat intake for maintaining hormonal processes forms at about ~1 gram per kilogram of body weight and should be derived from sources of healthy fats.


So far, you’ll now know that the three most important things for sustainable weight loss, are the following:

  • Calories in vs. Calories out (Moderate deficit)
  • Protein intake (Sufficient daily protein to sustain LBM retention)
  • Fat intake (Sufficient daily fat to sustain hormonal balance)

But what about carbohydrates?

Well, unlike protein and fats, carbohydrates are non-essential, as the body can produce glucose (the end product of carb metabolism) on its own, in a process known as ‘Gluconeogenesis (GNG)’.

What this means is that when you are creating a caloric deficit, you MUST create it mainly at the cost of carbohydrates.

Cutting carbohydrates may contribute most to the fat-burning processes, required for you to lose that unwanted belly fat and retain muscle mass.

However, it must be noted here that although carbs are non-essential, they must not be completely excluded.

As a matter of fact, they’re a VERY important aspect of your nutrition plan, as their end product (Glucose & glycogen) will be the MAIN fuel for your workouts.

A study has shown that carbohydrates are still very important for high-intensity exercise and their severe depletion will lead to suboptimal workout performance.

Suboptimal performance, in turn, means less lean muscle retention, and that’s not what you want.

So, you see, it’s about creating that fine balance, without going to extremes.

The best sources of carbohydrates are whole grains, as they do not spike blood sugar levels quickly, like plain sugar does.

Do you need cardio for fat loss?

two female friends running on a sunny day, trying to lose some weight

A commonly asked question is: how necessary is cardio for weight loss?

Well, contrary to popular belief, cardio is NOT necessary for weight loss.

As mentioned above, in order for you to allow the body to tap into the energy reserve, which fat is, all you need to do is create a caloric deficit.

This can be done through either decreasing food, or increasing activity (Move more), or both.

What we’re trying to say here is that at equated caloric deficits, there will be virtually no difference between someone who’s creating the deficit with cardio and eating more food, and someone who’s eating less but not doing cardio.

Cardio is no magic, however, it is a good tool to use, if you’re trying to create a caloric deficit.

Now, as mentioned, when dieting down, you also need to preserve lean body mass.

This is where one specific type of cardio can become a powerful ally for that goal – That is, HIIT, otherwise known as “High-intensity interval training”.

High-intensity exercise at a higher heart rate will more likely retain your lean body mass.

Let’s have a look.

HIIT vs. Normal cardio

High-intensity interval training essentially implies doing normal cardio, with bouts of high-intensity intervals.

For example, when running at a moderate pace, every 40 seconds try a 20-second sprint, then return to the same moderate pace.

This type of intense, short-burst movement is good for a couple of reasons:

  1. It activates the fast-twitch fibres
  2. HIIT increases the rate of fat oxidation
  3. It gives an “After-burn” effect – The body burns more calories for hours after the workout

What this means is that HIIT and sprints, in general, are a more intense activity, which makes the body release more anabolic hormones, as opposed to normal cardio.

As you should know, anabolic hormones are constructive hormones, meaning that you’ll simply maintain more muscle mass.

Now, though the rate of fat oxidation is increased and you burn more calories for hours after the workout, you still need to make an important note here.

That is namely the fact that at EQUATED caloric deficits, a faster rate of fat oxidation simply won’t mean more fat burnt.

Though that is the case, rest assured that HIIT will make you feel way better and lively.

lady running during sunset

Does the body fat percentage matter?

It seems like numbers have become an obsession for many trainees – bicep & waist circumferences, weight on the bench, and in your case with fat loss: numbers on the scale & body fat percentage.

Though your body weight and body fat percentage may be a reference point to check on your progress, they are not everything.

A person can look very different at a given weight, simply because body composition changes over time.

You must acknowledge that your ultimate goal should be looking better visually and performing better physically.

That is all that should matter to you unless you’re an athlete competing in a certain weight category.

If you obsess over numbers, odds are that at one point or another, the scale will stress you out as the weight fluctuates.

And stress is the last thing you need on a diet because stress hormones like cortisol literally SHUT DOWN your immune system & growth.

Again – Track how your body changes visually and don’t give much attention and energy to the body fat percentage & scale.

However, you should definitely use the scale to monitor the rate of weight loss and adjust the diet as needed.

For example, the scale can tell you if you’re losing too much or too little and whether you should increase or decrease food.

Summary of points to remember

An apple with 'summary' text indicating the conclusion of healthy principles lose belly fat fast article

In this article, you’ve learned the most important aspects of a successful weight loss plan.

There are things that are crucial, and then there are the ones that don’t really make that big of a difference.

Now let’s point out the more important points and talk through them briefly.

Note that the number list is in order of diminishing importance, meaning that the first point is the most important and the last point is the least important.

1. Maintain a lower total daily energy intake

If you want to let the body tap into the fat reserves, you can’t go about it without a caloric deficit.

Consuming less food than your body requires to maintain its weight, is the first and most important step when creating a weight loss plan.

It’s simple thermodynamics.

Then again, the caloric deficit must be moderate and not aggressive, as the body tends to lose both fat tissue and lean body mass, during a period of eating at a caloric deficit.

The optimal caloric deficit forms at about 500 calories per day, or, 1-2 lbs of weight loss per week.

If the individual is excessively fat or obese, the rate of weight loss can go up to 4-5 lbs weekly.

However, the rate goes back down to 1-2 lbs as the person gets back into a normal body composition.

2. Have a higher protein and fat intake

These are the two ESSENTIAL macronutrients for the body.

The caloric deficit MUST NEVER be created at the expense of proteins.

Proteins will ensure optimal recovery and help you retain lean body mass.

Total daily calorie & protein intake are the primary determinants for body composition.

Optimal protein intake falls in the broad range of 1.8-2.6g per kilogram of body weight, when the goal is muscle retention.

Note that the more trained you are and the more muscle you have, the more protein you will require.

On the other hand, you have fat intake.

Severe depletion of fatty acids will lead to many dysfunctions and a drop in hormonal levels.

This is exactly why sufficient daily fat intake must be present in a weight loss diet.

Optimal fat intake forms at about ~1 gram per kilogram of body weight.

3. Lower carb-intake

Though carbohydrates are on number 3 of this list, they are very important and must not be excluded completely.

Carbs are non-essential and their lack doesn’t really lead to any severe health issues, which is exactly why you should create the deficit mainly at the cost of carbs.

Overall, you need a balanced calorie intake and carbohydrates should still be present in your day to day nutrition because they’re the easiest and most efficient source of fuel for your workouts.

Low carb intake has been shown to hinder sports performance, which is exactly why, after having calculated protein & fat intake, you should give the rest of the calories to carbs.

Ultimately, a sufficient carb intake will allow you to perform better in the gym and hence, maintain more lean body mass.

4. Create a suitable meal pattern & sustainable diet plan

So, how many meals should you consume your food in? 2? 8? Every 2 hours?

Should you do intermittent fasting?

Well, truth is that lean body mass can be retained in a wide variety of meals – As low as 2 per day and as high as 6.

As to the diet type, go with what you prefer and what you can ADHERE to.

This is the BIGGEST problem with diets are that other people can’t adhere and stick to them!

If you really like intermittent fasting and can sustain it without causing stress, then go with it!

Ultimately, the goal for you should be creating a SUSTAINABLE PLAN which is one that you can stick to.

5. Consider supplements

There is no solid evidence to prove that a certain supplement will account for a better rate of fat loss in the long term.

No product can compensate for the lack of a sustainable diet plan, which is exactly why you should pay more attention to the above-mentioned points, rather than the newest fat-burners.

Now, of course, some supplements can help you at times when you need a good amount of protein but don’t have time to cook, however, your main focus should be on your diet & training.

An important final tip: resistance training is one of the best ways to maintain lean body mass whilst also losing weight.


Losing body fat fast can be very difficult, which is why creating a sustainable eating and training plan is the first pillar to a successful loss of fat.

Excessively quick fat loss is not recommended, as the body doesn’t like drastic changes and will adapt in a way that will allow it to quickly regain the suddenly lost weight afterwards.

This is exactly why you should rather change your eating and training habits, instead of looking for a quick and easy way out.

Ultimately, training and nutrition are a form of art (though a functional one), which is exactly why you should consider becoming the master artist of your body & your kitchen if you haven’t done so already.

We hope Healthy Principles have helped you understand how you can lose body fat fast. What strategies are you going to try to help you lose body fat fast?

Including more high-intensity interval training? Increasing the level of protein and fats whilst decreasing your amount of carbs?

Let us know by leaving a comment below right now!

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