This is not entirely accurate. Causing harm to people is not good. If you harm enough people egregiously enough, law enforcement eventually will notice and will figure which law said company broke. If the harm is bad enough, and intent obvious enough, they will find a law.
So, it's more true to ask: "Is intentionally manipulating food to cause harm to people-- is this consistent with existing legal norms?" I personally would not bet on it.
> intentionally manipulating food to cause harm to people
I seriously doubt that this has ever been done.
Companies "manipulate" food so it tastes good and they'll sell more of it. They don't intentionally do it to "cause harm". At most, that might be an unintended consequence.
It turns out that intentionally killing your customers is bad for business.
It's like (IIRC) Ozzy Osbourne's comment back in the days when metal was being blamed for teen suicides. "Why would we do that? That would tank sales for the followup album." Or Rob Halford on the same subject "If we were going to put backward-masked subliminal commands in our records, it wouldn't be 'kill yourself', it would be 'buy more of our records'"
(probably not exact quotes in either case, but that was the gist)
So, it's more true to ask: "Is intentionally manipulating food to cause harm to people-- is this consistent with existing legal norms?" I personally would not bet on it.