Wheat protein is used in bodybuilding primarily due to its protein content, which supports muscle repair and growth following resistance training. Scientific studies confirm that dietary protein contributes to muscle protein synthesis, a process crucial for muscle hypertrophy. While whey and casein are often preferred due to their higher essential amino acid content and superior digestibility, wheat protein can still contribute to daily protein requirements, particularly for vegetarians or those with dairy allergies.

Wheat protein is not considered a "complete" protein, as it is relatively low in lysine, an essential amino acid. However, when combined with other protein sources (such as legumes), it can provide a more balanced amino acid profile. Research comparing wheat protein to animal-based proteins suggests that, although less effective per gram, wheat protein still stimulates muscle protein synthesis, especially when consumed in sufficient quantities.

In summary, the scientific evidence supports the use of wheat protein as a supplemental protein source for bodybuilding, though it may be less optimal than animal proteins. Its main benefit lies in its accessibility for individuals on plant-based diets. The rating of 3 reflects solid evidence for general protein supplementation in muscle maintenance and growth, but with some limitations due to wheat protein's amino acid profile.