They are linked. If it can be deemed acceptable for the federal government to overstep its constitutional bounds and ban illicit drugs, how much of a stretch is it to assume they can and will do the same thing with fatty foods? Heart disease is supposedly one of the biggest killers in America, more deadly than illicit drugs. Doing something for "the future of America's children" is certainly noble but the war on drugs—to the extent that it federalizes what should be a state and local issue—is unconstitutional. To think that it isn't shows a shallow understanding of the serious issue of constitution abuse in America.
I know where you are coming from, but to intelligent folks, I think the comparison is in poor taste. No pun intented.
Hypothetically speaking, anything is possible, of course. So you may have a point about the food police. But I don't see the comparisons between illicit drugs and fatty foods/heart disease, at least not the way you're looking at it. There is a small group of people, who are trying to overplay their hand and win a big payout in the courts. In their defense, the approach these people are taking, is about dishonest advertsing tactics. Lying about the content of fat in fast foods, could ring true to a jury. At least on the surface, these possible court cases have more validity, then the law suits brought against cigarette manufacturers did.
I understand the Constitution and the national drug control policy of the US. The national drug control policy isn't unconstitutional.