Pea protein isolate is the main dairy-free alternative to whey: about 80% protein, no lactose, and a leucine content close enough to whey to support training. Its weak point is methionine, so over a day it pairs well with rice, oats or other grains, which carry the methionine peas lack. Refining removes most of the fibre and antinutrients that hold whole-pulse digestibility down, which is why an isolate scores far above cooked peas. Sodium is often high — it comes from the pH adjustment during processing.