There are three macronutrients that we obtain from food – protein, fat, and carbohydrates. They all provide energy, and all of them have roles to play in the structure and function of our bodies.
Both proteins and fats are required for human thriving and survival. Yes, remove either of these two macronutrients, and you are on a path to eventual disease and dysfunction. But are there horrible consequences for removing carbs, too? We’ll get there…
Let’s start with protein – proteins are made up of strings of individual amino acids. There are nine essential amino acids for the human body. What does it mean for a nutrient to be essential? It means that the body cannot make it on its own, and therefore the nutrients have to be obtained from food. Remove any one of these essential amino acids from the diet, and a range of consequences can occur, from a dysregulated immune system, muscle wasting, tooth decay, lack of mental focus, and hormone disruption, among others.
Likewise, there are essential fatty acids for humans as well. Essential fatty acids, coming from fat, can only be acquired from food. These essential fatty acids are categorized as omega-3 and omega-6 fatty acids, which can be broken down into further categories– alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are the omega-3 fatty acids, and LA (Linoleic acid), ARA (Arachidonic Acid), GLA (Gamma linoleic), and CLA (Conjugated linoleic acid) belong to the omega-6 category. Lack of these fatty acids in the diet (or the wrong ratio… a story for another time) can lead to hair loss, skin issues, the inability to heal wounds properly, anxiety, and depression, among dire consequences.
We’ve covered that there are essential proteins and essential fats. So what are the essential carbohydrates? Uhmm…. crickets.... there are none. Why is this? Well, the body can actually make carbohydrates from a process called gluconeogenesis. This is where glucose, the most simple type of carbohydrate, goes through a conversion process and is created from amino acids (i.e., protein). There are definitely times where the body needs to do this, for energy needs or structural needs, and the conversion process from protein to carb uses energy. But there are no essential carbohydrates, because the body can get away with not eating carbohydrates while still not experiencing some major type of dysfunctional results (provided it has enough protein to work with– and it will steal from muscles if necessary).
Protein, fat, and carbohydrates are also building blocks of the raw material making up our bodies. But en masse, our bodies mainly consist of protein and fat. Our muscles, which make up a large percentage of our body, are primarily made of protein. Our brains are primarily fat. Our hormones and neurotransmitters come from protein and fat. However, there are also structures utilizing glycoproteins, which involve the use of carbohydrates linked to protein. These are important in blood components, cartilage, bone, and cell-membranes. So while carbohydrates are indeed used in the body, they just make up less of the raw material.
So what does this mean for our everyday choices? Is it prudent to eliminate carbohydrates altogether? Not necessarily. Whole-food sources of carbohydrates are a great source of energy and fiber, which translates to easy fuel and a healthier gut microbiome. They also help maintain hydration (carbo-hydrate). Additionally, many carb-containing foods, such as vegetables, are incredibly good for your health. But if push came to shove, and we had to choose one of the three macronutrients to eliminate, carbohydrates may be the prudent choice.
If our physiology is telling us anything, it's that there are things it simply can’t go without – certain fats and proteins – but if needed, it can take care of the details of making carbohydrates if needed.
This simple fact is important to keep in mind when making food choices, specifically when it comes to keeping normal blood sugar levels and reducing the risk of diabetes. But again, that’s a story for another time…