I usually just put "YES" on foods because I tend to bring protein bars, nuts, etc with me during vacation and bring leftover ones back to US. I packed everything in a grocery plastic bag and open it for CBP agent, so far no issue.
I usually just walk to normal GE slip collection points (JFK, IAD, EWR is my primary arrival destination) with plastic bag. Sure it's little annoying to declare something that I BUY in USA but prefer be safe than sorry since I valued GE/TSA Pre big time.