I'm not sure I can follow. There is quite some data about vegetable oils being unhealthy, some of them being quoted by him. Why make this sound absurd?
That's not a very good analogy, given that the only reason fruit is healthy is because of all the fiber that slows down sugar absorption. If you drank the same amount of sugar in a moderate amount of fruit as juice it would be unhealthy.
Which is kind of his/her point. You can't just say x is unhealthy because it contains y like the Twitter twit does. You have to take into account actual usage criteria in which case the entire Twitter storm falls apart because it's comparing beef and vegetables.
This stuff is difficult to reduce to a pithy tweet.