The Science
Beef flank steak is excellent for muscle building due to its high protein content (21.7g per 100g, +43% DV), which provides essential amino acids for muscle protein synthesis. It also supplies zinc (+37% DV) and phosphorus (+16% DV), which support testosterone production and energy metabolism, respectively, both critical for muscle growth and recovery.
Recommendation
Include lean beef flank steak in your diet 2-3 times per week as part of a balanced meal with carbohydrates and vegetables to optimize muscle building.