If you're a young man eating a moderate amount of egg protein, adding some extra nonessential amino acids lets your body stay balanced with less food energy—suggesting that all amino acids together, not just the essential ones, might be holding back how well your body uses protein.

We analyzed the available evidence and found that 45.0 assertions support the idea that adding nonessential amino acids to egg protein may reduce the total energy needed for young men to maintain nitrogen balance. No assertions contradict this. The evidence we’ve reviewed suggests that when young men consume moderate amounts of egg protein, including extra nonessential amino acids—like alanine, glycine, or glutamine—appears to help the body use protein more efficiently, requiring fewer total calories to keep nitrogen levels stable. This doesn’t mean nonessential amino acids are essential, but rather that they may play a supportive role in how the body manages protein metabolism. Nitrogen balance refers to the state where the amount of nitrogen you take in from protein matches what you lose, which is important for muscle and tissue maintenance. The findings imply that the body’s ability to hold onto and reuse protein might improve when nonessential amino acids are present alongside essential ones, even though they’re not required in the diet. We don’t know exactly how this works, but the pattern across these 45.0 assertions points to a possible metabolic advantage. What we’ve found so far doesn’t prove this applies to everyone, or that it changes long-term health outcomes. It also doesn’t say how much extra amino acids are needed, or if the effect is meaningful in real-world meals. For now, if you’re a young man eating eggs as a protein source, adding foods rich in nonessential amino acids—like bone broth, gelatin, or certain vegetables—might help your body use that protein with less energy cost, but more research is needed to understand how this plays out in daily life.