This is the first of 3 articles outlining the basics of nutrition with regards to the 3 macronutrients Protein, Carbohydrates, and Fat. These are brief summaries that I hope you will find refreshing and informative.
Protein makes up most of our bodily tissues and is necessary for growth, repair, and healing of all of our cells. Protein is essential to life and provides structure to all living organisms. Aside from water, protein makes up the majority of our bodily tissues and fluids including muscles, ligaments, tendons, organs, hair, and nails, blood, etc.
Dietary Protein – proteins are organic compounds made up of amino acids and, chemically speaking, can be distinguished by both an amine group (NH2) and a carboxyl group or carboxylic acid (COOH) and, hence, the name “amino acidâ€; the general chemical formula is NH2CxHyCOOH. In nature, there are hundreds of amino acids; the human body, however, requires 20 amino acids of which, arguably, 8 are essential and, therefore, must be consumed through the diet. The term “essential†refers to the fact that these amino acids cannot be derived from other amino acids. If the body is not receiving sufficient amounts of protein or essential amino acids, it will draw upon its own tissue for them – a very scary thought in my mind.
A dietary protein can be classified as either complete or incomplete. Complete protein contains all 20 amino acids in sufficient quantity. Â Arguably, these 20 amino acids are listed and categorized as follows
| Essential | Non-Essential |
|---|---|
| Isoleucine | Alanine |
| Leucine | Arginine** |
| Lysine | Asparagine |
| Methionine | Aspartate |
| Phenylalanine | Cystein |
| Threonine | Glutamate |
| Trytophan | Glutamine |
| Valine | Glycine |
| Histidine** | |
| Proline | |
| Serine | |
| Tyrosine |
**Arginine and Histidine are only essential to children; Children are unable to synthesize either of these 2 amino acids
Recommended Complete Protein Sources include meats, fish, poultry, cottage cheese, whole eggs, egg whites, natural plain yogurt, and skim milk. Regular ingestion of protein throughout the day is recommended for several reasons including lowering hunger, proper brain function, mental alertness, regulation of body processes and formation of enzymes and hormones, slowing the digestion of sugars (we will get to this soon), providing a feeling of satiation, and providing the material necessary for consistent and on-going tissue recovery and rejuvenation. Remember, protein, unlike fat and carbohydrates, cannot be stored in the body; this is perhaps the strongest reason for regular protein intake. Depending on the individual and his\her respective fat and carbohydrate levels, I recommend 0.8 to 1.5 grams of protein per pound of bodyweight. Also, considering different sources of protein have varying amino acid profiles (different levels of amino acids), I recommend consuming a variety of protein sources on a daily basis. Please note that 1 gram of protein contains 4 calories.
Questions
Can I have nuts or beans as a source of protein?
You can, but not as a sole source of protein unless the missing essential amino acids are included. Nuts and beans (among others) are incomplete sources of protein. For example, nuts combined with a plant source such as bread or rice should provide a complete protein. However I prefer to stick with “clean†sources of complete protein. What I mean by this is a protein source that contains protein by a large majority with minimal fat and\or carbohydrate to protein ratio. I will get into this further when I write about nutritional timing.
How are proteins rated? I’ve heard eggs are the best source of protein. How do you know?
This is a great question. There are several methods for measuring protein quality including Net Protein Utilization (NPU), Protein Digestibility Corrected Amino Acid Score (PDCAAS), Biological Value (BV), Protein Efficiency Ratio (PER). I will not delve into these as you may find it rather boring and, in my opinion, they each have clear flaws. Eggs do in fact rate highly on both the BV and PDCAAS scale. PDCAAS is the widely recognized method approved by the World Health Organization (WHO), the Food and Drug Administration (FDA), and the United States National Academy of Sciences. As previously mentioned, I recommend a variety of complete protein sources coming from meats, fish, poultry, cottage cheese, whole eggs, egg whites, natural plain yogurt, and skim milk. It is my belief that the individual amino acid profiles of each protein source will compliment one and other, fulfilling a sufficient balance of all amino acids.
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