A new study has confirmed that animal proteins are superior to plant proteins in enhancing athletic capabilities.

In the context of sport, adequate protein intake as part of a balanced diet can significantly improve athletic performance, optimise body composition by reducing fat mass, and prevent certain diseases. Although plant-based protein supplements are gaining popularity, animal proteins are more effective for enhancing athletic performance. However, the true effectiveness of plant-based proteins in enhancing athletic performance remains to be studied, as the available scientific evidence yields conflicting results.

Plant-based proteins: limited benefits in sports

As an essential macronutrient, protein plays a crucial role in human health. In particular, animal proteins are widely recognised by nutritional science as superior to plant-based proteins. Several studies have shown that plant proteins offer limited benefits in sport: they do not appear to improve endurance performance. They can hinder the gains in muscle strength achieved through training in healthy individuals. Even soy proteins exhibit lower rates of muscle protein synthesis compared to whey, milk, and beef proteins.

Nevertheless, soy and pea proteins are considered promising supplements for supporting muscle protein synthesis and physical performance. However, further research is needed to confirm these benefits. A recent study aimed to evaluate the effectiveness of plant-based proteins on athletic performance in different age groups. The study analysed the impact of these proteins on muscle strength and endurance performance, as well as the rate of muscle protein synthesis, comparing them with animal protein sources, a low-protein diet, and a protein-free diet.

Various plant-based proteins were analysed, including soy, pea, plant-protein blends, wheat, potato, corn, mung bean and fava bean. To evaluate the impact of plant-based proteins on athletic performance in healthy individuals, researchers examined all existing randomised clinical trials on this topic, identifying 2,152 studies. After careful selection, they chose 31 trials that met rigorous criteria for meta-analysis, following an independent review process, data extraction and risk of bias assessment by two expert reviewers. This analysis is of high scientific quality and is supported by the GRADE system, a rigorous and transparent method for evaluating the reliability of available evidence.

Why are plant proteins not considered to be superior to animal proteins?

The study results showed that plant-based protein supplements only benefit athletic performance when compared to a protein-free or low-protein diet. Plant-based proteins were less effective than animal proteins in improving athletic ability in both young and old individuals. Animal proteins from sources such as whey, milk and beef were found to have a greater impact on muscle strength and physical performance in healthy individuals. Conversely, plant-based proteins were not shown to be more effective than animal proteins in enhancing muscle protein synthesis, strength, or endurance.

This systematic review and meta-analysis confirms that, while plant proteins offer benefits compared to low- or no-protein diets, they are not superior to animal proteins. The main reason for this is the amino acid profile of plant proteins, such as soy, pea and quinoa, which is less complete than that of animal proteins. This finding is consistent with previous meta-analyses, which have shown that animal proteins tend to promote greater gains in lean muscle mass, especially in young adults. In particular, beef, whey and milk are more effective than plant proteins at improving muscle strength and athletic performance.

High-protein supplements and diets are a promising area of sports nutrition, and their research continues to consolidate the available evidence. Currently, the evidence increasingly points to the clear superiority of animal proteins over plant proteins, in terms of not only muscle protein synthesis and health benefits, but also improved athletic performance.