Plant vs. Animal Protein Sources
The main difference between complete and incomplete proteins is that complete proteins contain all essential amino acids your body requires daily, and incomplete proteins only contain some essential amino acids. Your body breaks down the proteins you eat into amino acids, which build and repair tissues in your body, help digest food, provide energy, and perform numerous other body functions. Essential amino acids are also necessary for proper growth in children. Because complete proteins contain all essential amino acids, they are often referred to as high-quality proteins and easily utilized by your body.
A bit of a controversy is brewing over whether animal or plant-based proteins 4 are better for you. Some nutritionists argue that humans are better suited to digesting animal proteins since they are closer to our own biological makeup and contain all the amino acids we need to survive. On the other side, many contend that plant-based proteins are healthier and animal-based proteins are not necessary if you have proper variety in your diet.
While animal proteins have somewhat better absorption and availability to the body (See: The Protein Digestibility Corrected Amino Acid Score), what I’ve found is that most of the arguments for either side have less to do with the proteins themselves, and more to do with the foods in which they are found (i.e., meats being higher in fat and cholesterol vs. grains being high in carbohydrates) and the morality of eating animals. For most people, the body handles both types of protein equally well.
One potential problem with animal protein is that it tends to be higher in sulfur-containing amino acids, which causes increased acidity and could lead to calcium depletion as the body tries to balance out its pH level. This is typically not an issue when consumed in moderation with a well-balanced diet, however.
The only major knock on plant protein is its incompleteness, but that is, again, easily overcome with a well-balanced diet.