Despite being aware of the disadvantages
of junk foods, Why do we eat them?

the only reason people still eat it could be because no one really cares about what's in it, we just care about its taste, its smell, its appearance, and its reputation. (plus people are materialistic, they'll hide anything to get they money)

Explanation:

we need the speech to be able to answer your question, reply with it and i'll reply with the answer.

the narrator is saying that the old lady made her feel uncomfortable. you know this because they say "i found that rather irksome", "perhaps it was her being so upright and trim", and "i don't think it was that, because i thought that quaintly pleasant." hope this !