A nurse is reinforcing teaching about nutritional needs of preschoolers with a group of parents. Which of the following foods should the nurse recommend as a source of complete protein?

Complete proteins contain all nine essential amino acids in adequate proportions for the body's needs. Animal-derived foods are the most reliable sources of complete protein, and eggs are a classic example, providing all essential amino acids in a highly bioavailable form. This makes eggs the correct recommendation for parents seeking a complete protein source for preschool-aged children. Peanut butter is a plant-based protein that is notably low in the essential amino acid methionine; it is therefore an incomplete protein. Pinto beans are also an incomplete protein source, deficient in methionine and sometimes tryptophan; however, when paired with a grain such as rice, they can complement each other to provide a complete amino acid profile. Broccoli contains small amounts of protein but is primarily a vegetable rich in vitamins and fiber rather than a significant protein source, and it does not contain all essential amino acids in adequate quantities. When teaching parents about nutrition for preschoolers, it is important to emphasize complete proteins to support the rapid growth and development occurring at this stage. While plant-based protein combinations can meet needs, eggs offer the simplest single-food source of complete protein that is age-appropriate and accessible for most families.