NETA Personal Trainer Practice Exam

Which type of protein is formed by combining different food sources?

1. Complete proteins

2. Isolated proteins

3. Complementary proteins

4. Synthetic proteins

The correct answer is: Complementary proteins

Complementary proteins are formed by combining different food sources to provide all the essential amino acids that the body needs. Unlike complete proteins, which contain all essential amino acids in sufficient quantities (typically found in animal products), many plant-based proteins lack one or more essential amino acids. By strategizing dietary choices, individuals can pair certain plant sources—such as beans and rice—to create a meal that offers a complete amino acid profile. This approach is particularly beneficial for those who follow vegetarian or vegan diets, as it ensures they receive adequate protein without consuming animal products. Understanding this concept is essential in designing balanced meal plans that meet nutritional needs, especially for populations with specific dietary restrictions. In contrast, isolated proteins refer to proteins that have been extracted and purified from their original food sources, often used in supplements; synthetic proteins are artificially created in labs; and complete proteins are standalone sources that provide all essential amino acids by themselves.