Protein
Are the building blocks of the human body that are necessary in maintaining body tissue. Protein is made up of amino acids, which are building blocks for body tissue and are only burned for energy if the body does not have enough macronutrients (carbohydrates, fats). Protein is the last macronutrient the body will burn as a source of energy. The body will only use protein as a source of energy in desperate survival situations.

There are two different amino acids: Essential Amino Acids & Non-essential Amino Acids. The difference is, essential amino acids CANNOT be created by the human body and need to be consumed in food, whereas non-essential amino acids can be created internally by the body. There are 9 essential amino acids that need to be consumed in food sources, which can be found in complete proteins. A complete protein is a food source that contains all 9 essential amino acids in sufficient quantities. There are also incomplete proteins, which are food sources that do not contain all 9 essential amino acids.
Examples of Complete and Incomplete Food Sources
Complete Food Sources
These contain all nine essential amino acids in adequate amounts:
- Meat (beef, pork, lamb)
- Poultry (chicken, turkey)
- Fish and seafood (salmon, tuna, shrimp)
- Eggs
- Dairy products (milk, cheese, yogurt)
- Soy products (tofu, tempeh, soy milk)
- Quinoa
- Buckwheat
- Chia seeds
Incomplete Food Sources
These lack one or more essential amino acids:
- Grains (rice, wheat, oats, corn)
- Legumes (beans, lentils, peas)
- Nuts (almonds, walnuts, cashews)
- Seeds (pumpkin seeds, sunflower seeds, flaxseeds)
- Vegetables (broccoli, spinach, kale, potatoes)
Complementary Pairings
Combining incomplete sources can create a complete protein:
- Rice + beans
- Peanut butter + whole wheat bread
- Lentils + nuts or seeds
- Hummus (chickpeas + sesame seeds) with pita bread
Sources
- International Sports Sciences Association (ISSA). ISSA Curriculum Materials
For nutritional information, food sources and daily intake quantities for protein and amino acids please visit: https://dietfithealth.com/pages/nutrtion-facts
To learn more about nutrition fundamentals please visit: https://dietfithealth.com/pages/nutrition-fundamentals
To learn more about macronutrients please visit: https://dietfithealth.com/pages/macronutrients