What are proteins, carbs and fats? — The basics of real nutrition

Alexandra Iulia Soare
5 min readSep 30, 2019


You are probably wondering what is the difference between these macronutrients: protein, carbohydrates and fats.

Even if we heard these words a lot, probably you never had the chance to really find out what they really do in the body. That is why, what we are going to do in this article is to simplify and make it more clear by using a “house metaphor”. And no, I am not referring to Dr. House.

*Just a small disclaimer, this is a general overview of what the macronutrients do. Of course, they also have more complex roles in the body and interact in many pathways*


Imagine your body like a house. The fundamentals and the main structure is offered by proteins. While the energy is offered by carbs and fats. This energy can be used immediately or kept as storage.

PROTEIN = structure

In order to build a house, we need a material that is flexible and can be combined in different ways. That is why for our house we will use a series of 20 amino acids. Like Lego pieces, each amino acid has a unique form that can be combined to form proteins.

combination of aminoacids = protein

The biggest combination possible is 34,350 amino acids. This giant protein Titin is responsible for muscle elasticity. It is also known because its official scientifical name is the longest word in English with 189,819 letters and takes around four hours to pronounce correctly. The smallest combination is 44 amino acids. This is a protein that can code a small part of mRNA. As you can see, proteins can cover a whole variety of functions. Many think they only form muscles, but in reality they are also hormones, enzymes, immune system components, etc. Insulin for example? A protein. Antibodies are? Proteins.

In case you are in shortage of proteins and you need a fast boost, choose from the…



Alexandra Iulia Soare

Hi 🙋I am a food scientist! Do you want to eat healthier, but you don’t know where to start? Begin here: https://food-on-mars.com/work