Thanks for those links. Interesting. Yes, you're right. I learned that only recently. But IMO my original point still holds true if a person eats a mainly cereal- or mainly pulse-based diet (even if it includes other items like vegetables and fruit). Because then the body does not get enough of some needed amino acids to preserve and combine with others later. Of course this assumes they do not eat much of any other complete protein like dairy products or eggs. But that was my original premise, because I was talking about vegetarian food (and in the context of Indian vegetarian food). Almost all Indian vegetarians do eat dairy products (via tea, coffee, milk, buttermilk, yogurt, paneer, etc.), but not commonly enough to provide a significant amount of protein, is my guesstimate. Can't say about how many people eat eggs (I know many do), but it may be a significant percentage, and more so nowadays with more Westernization. But my comment was mainly about those who don't eat much of either dairy or eggs. Punjab may be a special case because they tend to eat a lot of paneer and drink a lot of lassi there, even if they are vegetarian.

I know that vegetarian means plants plus dairy plus eggs in the West, but am using the term in the Indian usage, where it usually means plants only, plus some dairy.