Before I start digging into these topics I need to put a big disclaimer on. I am no certified professional or doctor and I don’t play one here. I am simply sharing with you the juice of my own research and analysis regarding the topics or health, nutrition and training. You can also make your own and consult with a professional for any drastic and serious changes.

But I’ll bring up some science anyways.

Yet, I know I need to convince some of you first.

The premise of these “long” blog posts is to introduce you to the basics and ABCs you will need to understand all of what’s going on. I personally (being the nerd that I am) need to understand at a deep level how something functions so I can grasp it and implement it in my life. And that includes all things nutrition, training, new habits and techniques ect … Your body is this black box that inhibits all these systems and mechanism that help produce the desired output. Sadly, until now we cannot control the black box since it’s what we have been given (especially your genes and genome code). However, understanding the mechanism will help you tweak the inputs to serve all your goals not only your physical ones of fat loss, muscle gain, performance, … but also your productivity, mood stabilization, happiness and all those things we love. You can call it simply engineering your life. Try considering this epistemology, it will immensely help you deal with the exhausting information overload we are faced with in the digital age by making your solid science backed filter.

Now that I have explained to you why I will be boring you with some science, let me give you a synopsis of what I will be covering in a series of article

The ABCs of fitness and nutrition will include:

  • Fundamentals of food and nutrition Part 1 (this post) & (Part2)
  • Fundamentals of fat loss
  • Fundamentals of muscle hypertrophy (muscle gain)
  • All you need to know on bulking vs cutting

(if you have any other suggestions, please leave them bellow)

Now let’s begin talking about food and nutrition first because that’s the root of all evil.

In the world of fitness you’ve mostly heard of the rule “80% what you eat 20% what you do at the gym”. And it’s kinda true. You can go and run on the treadmill as fast as you can, lift as heavy as you can, but if your food isn’t managed accordingly you won’t see any results. Adding to that most specialists when dealing with clients who want to start their fitness journey, advise them to start with food first because you don’t want to be making too many changes at the same time. Beyond the physical and aesthetics, food affects your mood, focus, energy, mental state, immune system, digestive system, nervous system … Basically, all your life. Need more convincing?

NO …

Okay. So what is food?

I tried to think of a fancy intro for this but let’s cut things short. Yes, food is what we eat but we need to get more specific. Food is all what you consume and provides nutrients to the body. These nutrients are present in the form of carbohydrates, fats, protein, vitamins and minerals that fall into what you often hear macro (short for macronutrients) and micro (micronutrients).


In these series I will be talking mostly about macros and I will cover vitamins and minerals in later posts. Macros are what make up the calories aka energy in your body (will be explained later on).

What are carbohydrates?

“Euuuh nooo carbzzzz” in the latest trend of fitness, carbs are viewed as the enemy and the root of all evil but they are not. Carbs in their consumption come in a lot of forms; such as fibers (found in vegetables) and starches (bread, rice, oats …), glucose (sugar, honey ..) and fructose found in fruits and galactose found in dairy . What you need to know is that all carbs eventually become glucose (except for fibers) which is the main energy source for the body.

What is fat?

Fat used to be the bad guy to which we associated with obesity, heart disease, high cholesterol … What makes fat a fat, is the fat molecule (duh), triglyceride. They are found in oils, fish, nuts, meat … They come in various types, animal vs vegetal, saturated vs unsaturated. Unlike the common misconception, fats don’t exist to make us fat, they are the key elements that help start a lot of biological reaction involved in the body and help it absorb the vitamins and nutrients and maintain the hormonal balance.

What is protein?

Proteins is essentially made of amino acids that makes up about 75% of your body. They are essential for not only as we know muscle building and maintaining but also brain function, immune system and the reproduction of cells (think hair growth, skin repair after injury …). There are 21 amino acids but the body only creates 12, the remaining 9 are found in the food we eat and hence are called “essential amino acids”. Since we will be talking a lot about fitness, it is important to note that the amino acids involved in muscle building are called branched-chain amino acids aka BCAAs which are: leucine, isoleucine, and valine.

Since I didn’t want to get deep into the food chemistry, I found it interesting to note that all carbs, fats and proteins are made of atoms of carbon C, oxygen O and hydrogen H and a special addition of nitrogen N for proteins. That’s basically what you eat and what YOU are made of. (+ water of course).

How are these molecules utilized? Where do they go? What are they used for?

The main reason we eat is to provide the body with energy necessary for our body to conduct reactions necessary to its survival. There are two contradictory reactions happening in our bodies all the time anabolic reaction and catabolic reaction (keep this in mind as I will be reusing them in the muscle building article).

Anabolic reactions deconstruct big substances into molecular rubbles, such digestion, and releases energy in the process (but still needs a tiny bit of it compared to how much it releases). As for catabolic reaction, those rubbles reassemble to make bigger entities such as cell generation and the process requires energy.

You may be thinking, oh this is basic chemistry, well it IS !

At the metabolism level, our food is viewed as energy and building blocks (molecules of C,N,O and H, remember?).


[Heavy science alert] I know that so far we’ve covered the building blocks but what is energy? Asking that question is like asking what is money? The currency our body uses for energy is ATP (Adrenaline Triphosphate). I can see some of you cringing at this word remembering those boring high school biology lesson. However, bear with me I won’t dig deep into it. So how do we pay our bodies? This transaction happens through a process called cellular respiration, your best friend.

Glucose is the body’s preferred source of energy. What it does then is take a glucose molecule C6H12O6 and deconstructs it through oxidation and releases ATP; as simple as that. The conversion of glucose to energy simply occurs when we break down the energy bond of the glucose.

C6H12O6 + 6O2 à 6CO2 + 6H2O + 32ATP + HEAT

Even if you are just sitting down, chilling and doing nothing special, your body exerces the anabolic and catabolic activities and thus requires energy to stay alive.

[Resume reading] The total amount of energy required when your body is at rest is called BMR or basil metabolic rate. The luckier you are the higher your BMR would be, meaning the more you energy your body requires and thus more calories you burn while just chilling. A lot of factors influence the BMR and I’ll get into that when we will talk fat loss.

While this is the main and preferred way the body gets and uses energy, the other macronutrients also provide energy (ATP) to the body through catabolic reaction ( break down of large molecules to small ones). Protein gets broken down to amino acids and fats to fatty acids and glycerol. And since we need to consume all three macronutrients, a unit was chosen to calculate the amount of energy our body consumes and that is, you guessed it, a calorie. And this is how it goes:

1g Fat = 9 calories
1g Protein = 4 calories
1g Carbs = 4 calories

And this is where, ladies and gentlemen, calories came from.

But how many calories should we consume for energy?

[Heavy science alert] Scientist define it as TDEE or total daily energy expenditure and is comprised of what we call REE the resting energy expenditure and the NERR, non-resting energy expenditure. Your REE is your BMR; defined previously as the amount of energy your body needs to simply exist (breath, see, hear …)

NREE: include your other special activities in which we find

NEAT: non-exercise activity thermogenesis which is the energy your body burns through movement that is not related to intentional exercise. This could be from fidgeting, shivering, twitching, walking around the house

EAT: exercise activity thermogenesis which is the energy your body needs when exercising it includes a lot of other factors I will detail later

TEF: thermic effect of food, meaning the energy your body needs to is the energy the body uses to convert the food into more energy or to move it to a location to be stored (as fat) for use at a later time.

It all adds up to this simple equation:


I chose to put it in the details (not too much, trust me) of TDEE for you to know that there are a lot of factors that you can trick to your advantage to increase or decrease your TDEE. While it’s very helpful for those who really want to take their fitness extremely seriously, for others there’s a simpler formula used to calculate your TDEE that only takes into consideration your BMR and physical activity. Why? Because the other factors can be taken for granted (make up small percentage of TDEE) as you can see below.

Eric T Trexler , Abbie E Smith-Ryan, and Layne E Norton | Metabolic Adaptation to weight loss: Implications for the athlete [Research Gate]

[Resume reading] To calculate the BMR, we use the MIFFLIN ST.JEOR equation.

Male BMR: 10*weight + 6.25*height — 5*Age +5
Female BMR: 10*weight + 6.25*height — 5*Age -161

Weight in pounds (1kg=2.2 lbs) and height in feets (1m=3.28 ft)

Now that you got your BMR calculated, we need to introduce an activity factor to it so you can finally have the number of calories you should consume daily or what we call scientifically the total daily energy expenditure.



1,2: for sedantaries and if you have a desk job and don’t do much during the date
1,375: If you workout from 1 to 3 times a week
1,55: If you workout from 3 to 5 times a week*
1.725: If you workout from 6 to 7 times a week
1,9: If you are professional athlete or a job that requires you a demanding physical activity

My advice is to always be conservative and not overestimate your activity.

Now, this is the amount of energy you need to maintain a healthy body functioning at your level of activity. If you eat less calories (calorie deficit) your body retrieves the necessary energy from storage (fats) and if you eat more it fills up the unnecessary energy in the same storage. I will explain in more details the fatloss/fatgain process in the next article and how to estimate your daily calories if you want to lose a certain amount of weight in a certain timespan, stay tuned.

Now if we assume you know the amount of calories you need to reach your goal weight G (if your goal is to maintain your weight, G = your current weight).

Let’s find out how to calculate your exact macros.

Proteins = 0.8 to 2.0 * TDEE
Fats = 0.4*TDEE
Carbs = TDEE — Proteins — Fats

These macros ratios are not to be taken rigidly and you can slightly change them depending on your preference and your goals (stay tuned for that).

Now, what’s next?

Just enjoy your food!! According to your macro goals eat accordingly. That being said, I need to point out something very important that I would elaborate more on in the next part of this article. Eating healthy doesn’t necessarily mean you’ll lose weight and vice versa. If you have gone through all that science I have elaborated on above it’s all about the amount of energy you provide for the body. Your body doesn’t distinguish a carb coming from an oreo from a carb coming from an apple.

However, although for instance half a snickers bar and a banana have the same amount of calories. It is way healthier for your body to have a banana due to the other added benefits of micronutrients and it make you fuller and for longer.

Create this simple filter through which you view all your food. It’s all macros, micros and energy. There’s no magical pill, there’s no fit tea, there’s no waistband trainer that would make changes in your body.

But how can I measure my macros?

There are actually a lot of apps these days that allow you to measure the macros in each food you take and it shouldn’t be an issue. They even allow you to scan the barcodes of your purchased goods. My favorite to use is my fitnesspal that I highly recommend but you can use others as you please. What I advise you to do is for one week eat the way you do now and track it, you’ll be amazed at the results.

But I don’t want my life to be complicated and track my food all the time.

Yes, I hear you and I know. But just do it for few months until you acquire the intuitive skills of judging how many calories and macros exist in your food portions. I personally stopped tracking few month ago and I only do it now and then. I know roughly how many calories I eat and I take responsibility for my nutrition decisions. I know if I eat more calories than my TDEE I will gain fat and that’s just how the law of nature is we cannot do anything about it.

I know this was a heavy load of theory, but I will have more practical ones in the second part of nutrition fundamentals including what food to eat and some tips and advice from my own personal experience (though I am no expert by any means).

Thank you for reading and happy tracking !