Whey Protein

Whey is the liquid byproduct of cheese production — the watery fraction that separates from curd when milk is acidified or enzymatically processed. After concentration, drying, and (optionally) microfiltration to remove fat and lactose, it becomes the most-consumed protein supplement in the world. Whey's reputation rests on three properties: a complete amino acid profile (all nine essential amino acids in proportions well-suited to human needs), exceptionally high leucine content (~10-12% by weight, the threshold amino acid for muscle protein synthesis), and rapid absorption — plasma amino acids peak within 60-90 minutes after a 25-30 g dose. The scientific consensus, reflected in the International Society of Sports Nutrition's 2017 protein position stand, is that total daily protein intake of 1.6-2.2 g/kg supports muscle hypertrophy and recovery in resistance-trained populations, and whey is simply a convenient and well-absorbed way to hit that target. Whey is not magic and not categorically superior to dietary protein from whole foods — but it is cheap, palatable, and easy to dose accurately. The post-training 'anabolic window' framing was overhyped in the 2000s; current evidence supports a more relaxed view where total daily protein and distribution across meals matter more than precise post-workout timing.