Macro Nutrients Explained...

PROTEIN:

Protein is required in order to grow new tissue and maintain existing tissue. Aside from water, protein is the most abundant molecule found in the human body. It comes from the Greek word "proteios" which means "of first rank importance". Protein exists in all cells of the body and is the major structural component for all cells found in the body, particularly muscle. This fact also extends to include body organs, hair and skin. Protein is also used in membranes such as glycoproteins. Once they have been broken down into amino acids, they are used as precursors to nucleic acid and vitamins. Amino acids, the building blocks of protein, are involved in every biological process in the body. Hormones and enzymes are also formed from amino acids which are then used to help regulate metabolism, support the immune system and regulate other body functions.

Finally, the formation of blood cells also requires protein. For all these reasons, maintaining the required amount of protein to cater to your needs is crucial. As you can see, a protein deficiency will not only affect your ability to maintain/grow muscle tissue, but if not properly supplied, your body will be forced to pull the necessary protein-related nutrients from your vital organs, blood, muscle, etc.

CARBOHYDRATES:

Carbohydrates are basically sugars and starches. The body breaks carbs down into glucose molecules through digestion. Once broken down they can be used as energy (glucose) and fuel your brain and muscles. If the body is not currently doing physical work and has no significant need for glucose, it is then converted into glycogen and stored in the liver and muscles as an energy reserve. The body can store enough glycogen to last the average person about half a day. If the body has more glucose than it is able to use for energy as well as too much to convert to glycogen, the excess is converted to fat.

Carbohydrates, though not needed by the body, are the preferred fuel for the brain, nervous system and skeletal muscle. There are three major classes of carbohydrates: monosaccharides (simple sugars), disaccharides (two bonded monosaccharides) / oligosaccharides (more than two simple sugars) and polysaccharides (the most complex carbs).

FATS:
Also known as lipids, provides energy for the body as well. It also supports every important process occurring in the body from building new cells to regulating hormone production. There are three groups of fat: saturated fat, unsaturated fat and trans-fatty acids. Unsaturated fat can be broken down further into monounsaturated fat and polyunsaturated fat.

Vitamins A, D, E and K are fat-soluble, meaning they can only be digested, absorbed and transported in conjunction with fats. Fats are also sources of essential fatty acids, an important dietary requirement.