Again, in the act, “prescribed”, when you use it in this kind of context, means “prescribed by regulation”. You would read that whole phrase just before “foods” as “food prescribed by regulation”. It's a convention. It's also in the act, in section 2. It means “prescribed by the regulations”. It just leaves it for the regulations to define.
I will turn to Dr. Sharma regarding how we would do that, but that's certainly the convention.