When total daily protein intake is maintained at approximately 1.6 g/kg/day and distributed across three meals, a plant-based protein blend of soy and pea supports resistance training-induced muscle strength gains (64 kg increase in leg press 1RM) equivalent to whey protein in healthy young men, indicating that amino acid profile differences do not impair functional adaptation under optimal intake conditions.

When a person eats enough protein spread across three meals, the amino acid leucine from both plant and animal sources triggers a cellular signal that tells muscle cells to build more protein. This signal activates a key pathway that increases the production of muscle proteins, leading to thicker muscle fibers and stronger muscles over time with training. Even though plant proteins have less leucine per gram, eating enough of them makes the leucine levels in the blood just as high as from animal proteins, so the muscle-building signal works the same way.