PNP NUTRITION BASICS: Lesson 2 - Macronutrient Protein

When it comes to overall health, it is important to get adequate amounts of protein throughout the day. Protein is a component of food made up of amino acids, the building blocks for cells and tissues and other major parts of the human body. It is crucial for the minute-by-minute regulation and maintenance of the body, as well as for its ability to help us detoxify. The number of amino acids in protein can vary considerably, ranging from just a few to hundreds to thousands. There are about 23 different amino acids used to make protein, with approximately 20 commonly found in animal protein. In total, while there are 20 standard amino acids that contribute to the protein structure, 9 of these are considered essential and must be acquired through dietary sources to maintain optimal health.

Essential Amino Acids

These amino acids cannot be synthesized by the human body and must be obtained through diet:

1. Histidine

2. Isoleucine

3. Leucine

4. Lysine

5. Methionine

6. Phenylalanine

7. Threonine

8. Tryptophan

9. Valine

Non-Essential Amino Acids

These amino acids can be synthesized by the human body:

1. Alanine

2. Arginine (conditionally essential*, especially during periods of rapid growth or illness)

3. Asparagine

4. Aspartic Acid

5. Cysteine (conditionally essential*)

6. Glutamic Acid

7. Glutamine (conditionally essential*)

8. Glycine (conditionally essential*)

9. Proline (conditionally essential*)

10. Serine (conditionally essential*)

11. Tyrosine (conditionally essential*)

Conditionally Essential Amino Acids *

These amino acids are considered conditionally essential because, while generally synthesized by the body, they may need to be supplemented through diet during periods of illness or stress:

1. Arginine

2. Cysteine

3. Glutamine

4. Tyrosine

5. Glycine

6. Proline

7. Serine

How Much Protein?

When it comes to protein intake, a good general guideline is to aim for approximately 1 gram of high-quality protein per pound of body weight per day. For example, if you weigh 150 pounds, that would mean about 150 grams of protein daily—divided evenly throughout your meals for optimal absorption. Some people may need animal protein with nearly every meal in order to meet their needs. This approach supports muscle maintenance, recovery, metabolic health, and overall physical performance, which are especially important when working to change body composition or preparing for physically demanding situations. 

To put this into perspective, a 6-ounce skinless chicken breast provides around 34 grams of protein, a 6-ounce lean steak (like sirloin) offers 36-46 grams, and a 6-ounce portion of salmon or cod typically contains 33-35 grams, depending on the variety. While individual needs will vary based on activity level, age, and current body composition, this is a strong baseline for most active adults. A simple visual cue for how much protein a meal is providing is to make your portion of protein roughly the size of the palm of your hand.  

Signs of too little protein can include sugar or sweet cravings, mental fog, fatigue, weakness, unintentional weight loss, skin issues, changes in hair texture or color, and even anemia. Whether you're focused on health, fitness, or being physically prepared for emergencies, consistent, high-quality protein intake is essential to staying strong, energized, and resilient.

Soy Protein: Considerations for Use in a Preparedness-Focused Nutrition Plan

While soy protein is a complete plant-based protein, there are several reasons why it may not be the best primary source for individuals focused on optimizing digestion, hormone balance, and lean muscle development.

1. Digestibility Concerns
Soybeans naturally contain protease inhibitors, compounds that can interfere with the digestion of protein by blocking enzymes like trypsin and chymotrypsin. Although these inhibitors are significantly reduced through cooking and processing, some individuals still experience gastrointestinal discomfort, such as bloating or gas, after consuming soy products [1][2]. Despite high digestibility rates in isolated forms (92–97%), soy may still be less tolerated compared to other protein sources like whey [1].

2. Genetically Engineered Crops
Soybeans are among the most genetically modified crops in the world. In the United States, approximately 94% of soybeans planted are genetically modified to resist herbicides [3]. While GMO soy is considered safe by the FDA and USDA, some individuals prefer to avoid it due to environmental, ethical, or health concerns. Choosing certified organic or non-GMO labeled soy products is a more suitable option for those with such preferences.

3. Estrogenic Effects of Soy Isoflavones
Soy contains phytoestrogens- plant compounds that can weakly mimic estrogen in the body. These isoflavones, particularly genistein and daidzein, can bind to estrogen receptors, but they have a much weaker effect than human estrogen [4]. Concerns have arisen regarding the potential for soy to disrupt hormone levels, particularly in men, or to negatively impact testosterone.

Note: Isoflavones are a specific subclass of phytoestrogens, plant-derived compounds with estrogen-like activity, found primarily in soy and other legumes, making them one of the most potent and well-studied types of dietary phytoestrogens.

However, multiple studies have shown that moderate soy intake does not decrease testosterone levels or negatively impact muscle gain [5]. Still, for those with hormone-sensitive conditions or seeking optimal muscle-building outcomes, it may be advisable to use soy as a supplementary protein source rather than the foundation of their intake.

4. Muscle Gain and Protein Quality Comparison
Soy is classified as a complete protein, but its amino acid profile, particularly its lower leucine content, may not stimulate muscle protein synthesis as effectively as whey protein. Studies comparing soy to whey protein have shown that whey tends to produce superior outcomes in lean muscle gain over time, likely due to its higher bioavailability and amino acid profile [6].

References

1. Wikipedia contributors. Soy protein. Wikipedia. https://en.wikipedia.org/wiki/Soy_protein

2. Cleveland Clinic. Soy Allergy. https://my.clevelandclinic.org/health/diseases/11320-soy-allergy

3. U.S. Food & Drug Administration. GMO Crops, Animal Food, and Beyond. https://www.fda.gov/food/agricultural-biotechnology/gmo-crops-animal-food-and-beyond

4. Harvard T.H. Chan School of Public Health. Straight Talk About Soy. https://www.hsph.harvard.edu/nutritionsource/soy

5. Messina M, et al. Soy Protein Intake Does Not Affect Testosterone Levels in Men: A Meta-Analysis of Randomized Controlled Trials. Fertility and Sterility. 2010. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1470658/

6. InsideTracker. Whey or Soy Protein: Is One Better? https://www.insidetracker.com/a/articles/whey-or-soy-protein-is-one-better

In all cases, we recommend that you purchase the highest quality protein you can. This means sources that are organic, naturally fed, pasture-raised or wild, and, whenever possible, fresh rather than frozen. While terms like "cage-free" are often used by large corporations to give the impression of ethically raised animals, the reality is that many of these animals still live indoors in crowded conditions with limited access to the outdoors. "Pasture-raised" is a more reliable indicator that the animal was allowed to move freely and eat a more natural diet. Conventional protein production increasingly relies on hormones, antibiotics, and unnatural feed, as well as confinement systems that severely restrict mobility throughout the animal's life. 

If purchasing “fresh” meat and fish isn’t possible, frozen may be the next best option and sometimes the only--option. When choosing frozen meats and fish, always look for a clearly labeled freezing date, not just a “best by” or “sell by” date. The closer the freezing date is to the time of harvest or processing, the better the product’s nutritional value and taste. Choose vacuum-sealed or tightly wrapped packaging with no visible tears, air pockets, or excessive ice crystals, as these can indicate freezer burn or poor temperature control. Properly sealed frozen fish can generally be stored for up to 6 months, while poultry and red meats can last up to 12 months in a consistently cold, well-maintained freezer. For best results, use a freezer thermometer to ensure the temperature stays at or below 0°F (-18°C).

Canned fish and chicken are a convenient way to have a quick and easy protein option on hand. Look for fish canned in water or olive oil. Sardines are a great example of a whole food (most often, we eat just a fragment of an animal). Sardines are canned whole and are a great source of calcium. Canned wild salmon is also a good choice and can be used to make tasty salmon burgers.