The problem with studies is who does them and their agendas.
The majors sources of cattle feed in this country are grasses, other grains, specifically maize (corn), and silage (waste from grains harvested for human consumption). Soy is too expensive for most cattle ranches and wholesalers preparing cattle for slaughter, but soy silage is affordable. Most soy consumption is with pet foods. We spend more as nation on feeding pets than we do raising children. Which explains teenage angst and depression, while dogs and cats rule with smiles on their faces.
Sweden is weird. Here we use sawdust for making compressed wood products like the press board used in construction and cheap furniture manufacture, not as fuel or food. In Sweden, sawdust is a recommended flour additive. Here it is outlawed from flour.
80% of the world's soybean production comes from the US, Argentina and Brazil. Most of the balance by China, which imports 70-80% of the world's soybean crops, almost all of imported soy is used to produce soy oil for cooking. They uses the silage to feed poultry and pork, feed for fish farms. The Chinese use soy oil for cooking, machine lubricants and as an additive to diesel fuel in factories. It is less expensive than diesel oil and other additives. Equally as polluting.
In India, meat has been traditionally more expensive than vegetable produce. The Hindi worship cows and don't eat them. Mutton, goat, pig, and poultry are the major sources of meat in the Indian diets. Outside of meats, fish are the major source of proteins in the Indian diets, especially in coastal regions where the majority of population resides. As India's middle class grows, meat consumption rises. The Mediterranean diet is famous for substituting fish for meat as a protein source. With depletion of the fisheries, Mickey Dee's are spreading and growing popular in Mediterranean countries. So is obesity.
What "could be" has little to do with what "is."
While walking the dog this morning, I ran into a woman in the neighborhood who I have known for 20 years. She's been a strict vegan. She's recently been diagnosed with pre-cancerous pancreatis. As part of her therapy, she must consume at least 6 ounces of ungulate products daily. Whole milk and cheeses so far. Nothing in this world is what it seems.