Basics

It's helpful to understand the basics of calories and macronutrients, so that you have an idea of what they are. I will only give a very brief description so you can understand the fundamentals but with little scientific detail. The goal is to give you a basic education, not a nutrition degree.

Calories

It represents the energy that a certain food contains. Your body is a machine that is running all kinds of complex physiological processes to keep you alive and for you in order to move and do everything you do. There are countless biochemical reactions that make them possible, and each requires energy.

In order to understand how fundamental calories are, especially for fat loss, I like to give the analogy of a cellphone. Your cell phone can do all kinds of things. You can open Instagram, take a photo, make a call, etc. Very much like your body! All those tasks require energy. The more intensive the task is, the more energy it requires. And by doing many tasks, you slowly drain the battery. This is exactly how the human body works as well.

When you run out of battery, the phone shuts off. Why? It doesn't have enough energy. Likewise, if you don't have enough fuel to feed your body, your body shuts down. In this case, shutting down here means starving to death.

Fortunately for your cellphone, you can easily bring it to "life" by charging it, but that's not possible with biological life (so far!). So running out of energy is very dangerous! Especially before civilization when food wasn't always easy to get. The solution that evolution came up with is... a power bank. If you need energy and you can't afford to run out of it (because you die), a good solution is to store energy so that you can use it later. This is what body fat is.

This is why calories are what determines weight loss and weight gain. If you are not eating enough energy to match the demands of your body, your body would not be able to function and shut down. Therefore, it has to rely on stored energy, and by using that energy, you lose fat. And if you are eating more energy than it needs, then that energy is stored so that it can be used later when needed.

It's very common to read on the internet that calories don't matter, that it's about a specific macro-nutrient, hormones, food group, etc. This is false. And while there are certain nuances, not only have such views been disproven in research, but also they can't possibly be correct on principle alone, as it would violate the laws of thermodynamics. As it is quite obvious from the analogy given, you cannot create energy from nothing, it's a basic feature of the universe. If you're lacking energy, there is no special food or hormonal change that can fuel your body, it's just not possible.

This was pretty lengthy, but it's crucial to understand this point well; otherwise, it's very easy to spin your wheels when you can't understand the underlying problem.

Macronutrients

There are 3 macronutrients:

• Protein

• Carbs

• Fat

Technically, alcohol is a 4th, but we can ignore that for convenience's sake.

Macronutrients are subdivisions of calories. Meaning that all macronutrients contain calories, and all calories come from a specific macro-nutrient.

Protein

The most crucial macronutrient. As you likely know, it is very important for muscle, since protein is literally the building blocks that muscle is made out of. But they also play a crucial role in many other bodily functions, it's required to make enzymes, skin, hair, connective tissue, and so forth. You will find a full food list later on, but protein foods are things like meat and fish.

Carbohydrates

They are mostly used for energy. It maintains blood sugar levels, and it's also an energy reserve for exercise, especially with higher intensities. An appropriate carbohydrate intake makes sure that you have the energy to perform well in the gym or at your sport. Some carbohydrate examples are bread, pasta, and fruit.

Fats

They are important in order to maintain optimal health. They are required in order to absorb fat-soluble vitamins (A, D, E and K), and they are the building blocks of cellular membranes (like protein for muscles). They are also needed to maintain your hormones at a healthy level.