Problem in the 70s was trans fats. Now they're no longer a risk, replacing butter with margarine is a solid evidence-based decision for one's health (though not so much for one's enjoyment!).
Okay, the cereal commercials in the 1980s: they would have some ridiculous cartoon mascot and sing a catchy jingle about their sugary cereal treats, and then at the end, they were legally required to say "Part of this balanced breakfast" while displaying a tray laden with fresh fruit, buttered toast, perhaps a glass of orange juice.
Those commercials played multiple times a day in my childhood, and they never failed to piss me off, because they clearly demonstrated that "milk and a box of Chex" was not by any means a "balanced breakfast".