I have one comment about the content and then just one or two little things about details.
Content-wise, your second point about the title of the episode could be made a little stronger. Right now, you simply say that the title conveys that the episode is about weight gain. But the use of the whale analogy is beyond that. The idea of connecting whales and fat people is very cruel and shows the extent to which people look down on people who are overweight. You should mention this instead of just saying the title shows that the episode is about weight gain.
As for details:
“has led today’s society to becoming…” “Becoming,” in this sentence, should just be “become.”
In the sentence that starts “Secondly,” you can’t call this the following episode because you’ve already been talking about it. You could call it “this episode” or “the episode we are discussing.”