Hopefully, we have a clear understanding of the role energy balance plays in our body, but that is just the base. When we put that concept into practice we quickly realize that is not as easy as just a thermodynamic formula that looks at the laws of energy conservation, the magic is in the composition of that energy.
Calories come from three main macronutrients (macros), proteins, carbohydrates, and fats. Typically, you will find that most foods are a combination of these three macros. Fats are called “fats” if their main macro comes from fat. For example, a Brazil nut contains carbs, proteins, and fats, but the amount of calories coming from fat far outweighs the other two, that's why we call Brazil nuts a “fat source”.
Whenever we hear someone saying “I'm tracking macros”, what they mean is that they essentially are recording their protein, carbohydrate, and fat intake. Tracking apps are the best tool we have at the moment to record this data. It gives us a detailed overview of what went into our body, its nutrients, energy balance (calories), amino acid profile, etc. A few apps we’ve tried are: myfitnesspal, mymacros+, chronometer, and trifecta. We use these apps because we want accurate data, so we can make informed decisions on what's working and what's not working.
Now that we have a basic idea of what macros are, let's dive into each of them separately.
Proteins are long chains of amino acids that serve as the building blocks for your cells, muscle tissue, connective tissue, etc. There are 22 amino acids that your body needs to properly function, out of those, 9 are called the “essential” amino-acids”, because our bodies can't make them, so we have to get them via protein sources.
There are different types of protein:
1) Lean proteins ( >10% fat ): Egg whites, white fish, bone broth, protein powder, beans/legumes, etc.
Fatty proteins (<10% fat ): Beef (most cuts), whole eggs, milk, bacon, salmon, lamb, etc.
“Specifically, what happens when we eat protein?”
Well, the roles of protein are many, here are a few reasons why you want to make sure you are eating proper amounts of protein:
1) Increased thermic effect of food.
Out of all three macronutrients, protein uses the most energy in the digestive process, leading to a higher metabolic rate. Meaning, fat loss and muscle retention in a caloric deficit and muscle gain when trying to get heavier.
Protein requires around 20% of the energy it provides just for digestion and absorption, while carbs and fats require around 5%, in other words, if we eat 100 calories worth of protein, we are actually using around 20 of those calories just to be able to absorb the 100 calories ingested.
2) Increased protein turnover.
Your cells are continually replacing and improving themselves, this is called turnover. The balance between breaking down muscle tissue and rebuilding it, improves protein synthesis, therefore when we eat more protein, we recover our muscle tissue faster.
3) Increased fat loss in periods of caloric restriction.
When we consume protein, we also increase the plasma concentrations of a hormone called glucagon. One of glucagon’s roles is to antagonize insulin’s response in fat stores, leading to greater fat mobilization.
4) Nutrient Density.
When we eat protein, we are eating more than just amino acids, we are also eating other nutrients. Among some other sources, when we eat protein, we typically get branched-chain amino acids, creatine conjugated linoleic acids, etc. This illustrates the need to get most of your protein from food, not protein powders.
“How much protein should I eat?”
It depends. A good starting base is to be around 1.2-2.5 gr per kg, most of us are going to be among these ranges. Our specific targets are going to vary based on:
Activity levels (The protein demands of an elite-level powerlifter are bigger than someone who just wants to excel at their desk-job)
Age (as we get older, we don’t absorb protein as well)
Sex (males synthesize protein better than females)
"Mmm, I still don't get it, why not just follow a template?"