We’re going to shift gears for the next couple months here and talk about nutrition. You know, that big scary word that no one really knows for sure what it entails, and the recommendations from the “experts” for it change every five years or so. I am not going to go too much into the weeds here, but I do hope to give you a general idea of the basics of nutrition so that you are better able to communicate about nutrition. This month we are focusing on Protein.
What is Protein? Well, first off let’s take a step backwards and talk about Macronutrients.
What are Macronutrients? Macronutrients are the nutritional components of a diet that are needed in large amounts to sustain growth and life. We consume macronutrients in the form of foods or drinks, which provide us with the bulk of our energy as well as providing fuel for constructing the human body. Protein is one of these macronutrients, the other two being Fat and Carbohydrates.
So what is Protein? Proteins at their most basic, are composed of carbon, hydrogen, and oxygen atoms. They also contain nitrogen atoms (unlike fat and carbohydrates). “Amino” means “nitrogen-containing,” therefore, amino acids are the molecules that, when joined in groups of a few dozen to hundreds, form the thousands of proteins occurring in nature. Essentially, proteins are chains of amino acids.
Proteins in the human body are composed of 20 amino acids, nine of which are “essential” because the body cannot manufacture them and therefore they must be obtained through the diet. Five of the amino acids are able to be synthesized in the body, and the remaining six are conditionally essential amino acids whose synthesis can be limited under special conditions.
These five able to be synthesized by the body are alanine, aspartic acid, asparagine, glutamic acid and serine. The six conditionally essential amino acids are arginine, cysteine, glycine, glutamine, proline and tyrosine. The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Since most of these amino acids are either not able to be synthesized by the body, or conditionally synthesized in the body, it is generally best to consume them in our food. As you may already know, dietary sources of protein include meats, dairy products, fish, eggs, grains, legumes, nuts and edible insects (for the daring).
All of these amino acids have varied and important jobs within the body. Probably the most important, at least for our discussion today, is for protein synthesis and muscle repair/remodeling. The reasoning for this is that during cell turnover (the constant breakdown and regeneration of cells) the immediate supplier of amino acids is the body’s free amino acid pool. If they are not in the body, your body cannot use them to make new cells (think muscles)! In addition to being one of the building blocks of body tissue, they can also serve as a fuel source, especially in long (like really long), slow, aerobic exercise. This is why those who specialize in very long and slow aerobic exercise tend to have a “muscle-wasting” appearance. In their case, their bodies are literally using their muscles as an energy source.
Ok, so now that you know a little more about protein, what next? Well, how about how much should you be eating? Good question. When estimating the protein requirements for individuals you need to consider two factors: the caloric intake, and the biological value of the protein.
When caloric intake goes down, the protein requirement goes up. Protein is only one of the building blocks used to create new tissue, so if there are plenty of other building materials around, the need for protein is not as high. However, if the calories are being restricted, protein may be used as a source of energy instead of other sources (carbohydrates), and the protein cannot be used for the intended purpose of replacing the amino acid pool. In this case, protein should make up a larger portion of the calories to ensure that enough building blocks are present.
The higher the biological value of the protein, the lower the protein requirement. Protein sources are not all equal, and some sources are significantly better than others. The best sources of protein have amino acid profiles similar to that needed by the body, and include proteins of animal origin – those in eggs, meat, fish, poultry, and dairy products. Grains, beans, vegetables, and gelatin are referred to as low-quality proteins as they lack one or more of the essential amino acids needed by the body. Unfortunately for vegetarians and vegans, protein quality is one of the issues that must be considered. While not impossible to attain, it is much more difficult for these individuals to get the quality protein that they need.
Now, with that out of the way, assuming that caloric intake is adequate and that two-thirds or more of the protein is from animal sources, the recommended intake for protein for adults is about 0.7 g/pound of body weight for both men and women. This recommendation is generally for sedentary individuals, which we are not, so those participating in CrossFit will likely need to increase their protein intake to as much as 1.0g/pound of body weight or more. Those individuals consuming a vegan diet may need to increase their protein intake even more. That might seem like a lot of protein, and you would be right, but most people do not eat enough protein, especially women.
If you are looking to increase your protein intake, my recommendation is to start out small. If you barely eat any protein now, quadrupling the amount you eat is going to potentially leave you with some gastric issues… Instead, be a little more mindful of your food selections and choose items that have more protein in them. Once you grow accustomed to your new protein intake, bump it up again. Continue this process until you are at your goal number. One additional benefit of protein is that it stimulates satiety hormones, so you will feel more full after a meal and stay satiated longer – an added bonus for those looking to lose weight!
