A lot of nonsense is being told about fat, and this programme, "Die Wahrheit über Fett" on ARD Mediathek sets the record straight, including on what is known (not much) and what is not known (a lot).
The first highpoint is no doubt that butter is not nearly as horrible a product as the health-food industry has made it out to be in massive advertising campaigns.
The second highpoint is that the people from the Bundesinstitut für risikobewertung are issuing warnings about the lack of evidence of the benefits of Omega-3 oils and are campaigning to determine a maximum concentration of these oils in food, because of the distinct dangers caused by these supposed 'miracle' oils.
Once again, it turns out that reality is far more complicated than what the health-food industry claims in its messages. These messages are clear and simple, but as H. L. Mencken said:
For every complex problem there is an answer that is clear, simple, and wrong.