Plant-Based Diet: Is It as Good as an Animal-Based Diet When It Comes to Protein?

Abstract

Protein is a macronutrient that is responsible for multiple functions in the human body and is made up of twenty amino acids. Nine amino acids are not synthesized in the human body and require dietary ingestion to prevent deficiency. These essential amino acids are easily obtained through animal-based proteins but can be in limited quantities through plant-based protein sources. With the obesity epidemic rising, great attention has turned to plant-based protein diets and their health and environmental implications. The differences in plant and animal protein sources have been explored for their effects on general health, sarcopenia, and muscle performance. This review discusses the benefits and drawbacks of a plant-based diet, as well as some of the latest literature on muscle protein synthesis between animal- and plant-based dietary intakes of protein. High meat consumption is associated with increased saturated fat intake and lower dietary fiber intake. As a result, meat consumption is correlated with obesity, heart disease, metabolic syndrome, and gastrointestinal cancers. However, animal-based diets contain higher amounts of leucine and other essential amino acids which are associated with increased anabolic potential and muscle protein synthesis. Yet, multiple studies show conflicting results on the true benefits of animal-based diets, suggesting total protein intake may be the best predictor for preserving lean muscle mass and increasing muscle performance. While many studies support animal protein sources superior to plant-based diets on intracellular anabolic signaling, other studies show conflicting results regarding the true benefit of animal-based protein diets on overall performance and effect on sarcopenia. The health benefits seem to favor plant-based protein sources; however, further research is needed to examine the effects of protein from plant- and animal-based diets on muscle mass and protein synthesis.