> "Free markets" require a perfect knowledge of all things about those products that is constantly kept up to date. As soon as a company is bought out, some brand decides to change their ingredients, or any number of other events, then you're back at square one.

As mentioned in a sibling comment, while this is theoretically an issue, it doesn't happen often enough in practice that it causes a burden

>Ethical consumerism is a constant treadmill. Even knowing which brands are owned by which corporations is an absolutely exhausting affair.

Why are you mixing ethics into this? We were talking about making healthy purchasing decisions, not boycotting [insert brand here] because they punch kittens or whatever.