In my opinion there really isn't a difference between the two phrases.

The difference is not in meaning, it's in usage. I like chicken. How about you? That sounds like you're asking, do you also like chicken? When you say "how about you," you are assuming the topic will remain the same. I like chicken. What about you? This sounds like you're asking, "what food do you like?" Here, you are allowing the topic to change. That's usually how it goes. Like other examples: 1. I think I did good on that test. How about you? (How do you think you did on this particular test?) ---Yeah, I think I did good too. I think I did good on that test. What about you? (What did you do good on?) ---My chemistry exam was horrible today. 2. I liked After Dark by Haruki Murakami. How about you? (How do you feel about this particular book) ---I don't know how I feel about it yet, I haven't finished. I liked After Dark by Haruki Murakami? What about you? (What book (not a particular book) do you like?) --I like 1Q84 more.

Same meaning

I think these are have the same meaning.