Protein supplementation myths: Evidence-based insights for health and performance

This review dispels key myths about protein supplementation, providing evidence-based findings across various health and performance outcomes. Addressing kidney health, it highlights that protein intakes up to 4.4 g/kg/day show no adverse effects on renal function in healthy individuals, though specific conditions like chronic kidney disease may require controlled intake. Regarding bone health, high-protein diets do not increase osteoporosis risk; instead, they can enhance bone mineral density when paired with adequate calcium.

In terms of body composition, high-protein diets are shown to support lean mass gains and fat reduction, even under calorie-restricted conditions, debunking the notion that excess protein intake leads to fat gain. Studies report that protein intakes above 1.6 g/kg/day optimize muscle protein synthesis (MPS) post-exercise, though MPS can be stimulated effectively throughout the day without strict post-exercise timing.

For vegans and vegetarians, the review clarifies that sufficient training adaptations are achievable with a higher intake of plant proteins, due to compensating for lower leucine content by volume. Research notes that plant-based proteins, when carefully managed, can support similar muscle and strength gains as animal proteins.

Endurance athletes benefit from protein intake exceeding the RDA, as it aids in glycogen replenishment, immune health, and recovery. For those concerned with protein "overload" in one meal, recent findings suggest an anabolic response even at doses up to 100 grams per meal, challenging the previously assumed 20-30 gram threshold.