The biggest issue with soy, is soy meal not processed through the expelliar method. It's chemically processed with residue of things you really don't want in your food. Using whole roasted soy eliminates the potential of that. In terms of those who are allergic, many of them have been eating eggs and meat fed with whole roasted soy for years, without issue. Just as an example, Polyface farms uses 605lbs in their broiler feed and 620lbs in their layer feed per ton. 1020/1000 lbs of corn as well. If and when I can get it, I prefer feed from Sunrise Farms in VA, they supply polyface and I've had my best success either with their feed or following their recipes.So it looks like some negatives to soy are that a lot of people are allergic to it. I read where eating the eggs can bother them. The soy can also cause deficiencies in their diet, but I assume the food manufacturers add those into the feed as needed. Can’t say that I found anything saying why it was positive though. Only read negative things or arguments why it wasn’t bad. But didn’t find anyone saying it was healthier.