Proteins are complex molecules that form the building blocks for pretty much everything in your body including your cells, tissues, organs and cartilage. When molded into different shapes, proteins enable your cells to communicate with each other by forming hormones, receptors and other signaling biochemicals. They are critical in pretty much every aspect of bodily function including our metabolism, respiration, immune system, muscle growth, waste disposal and basic cellular functions. In a nutshell, they are the biochemical workhorse of your bodies.
Protein is arguably the most important macro in terms of the benefit to your body and as most of your body is made of protein, it is important to make sure you are getting enough in your diet to prevent muscle loss. Protein is a great macro for weight management because it not only helps with the numerous protein-related functions within your body, but it is also the best macro for helping you to feel full. Due to its high thermic properties, you have to burn more calories to digest, absorb, transport and store protein than either fat or carb macros. And as the body always looks for the easiest source of energy, it prefers to store any excess energy from fat or carbs macros in body fat as this requires less effort to be converted back into energy than protein.
Proteins are made up of long chained compounds called amino acids. When we eat proteins, their molecules are broken down into amino acids and peptides (which are compounds consisting of two or more amino acids) by various enzymes and acids within the gastro-intestinal tract. These amino acids and peptides are then absorbed into the bloodstream where they get to work, trading with the amino acids already in your cells and providing a continuous supply of replenishment for cellular growth and repair.