How do I respond to "Would you still love me if I was fat?"

My wife (25) hit me (29) up with that a couple of days ago.

She basically asked me how important looks are for me because beauty will eventually fade and she does not care about looks (bullshit).

I mean, she is right, she wont look good with 60. But she can definately look good with 40-50.

I responded with something like "Of course personality makes you love someone but you also need looks to be attracted to that person,"

I hardly doubt that she would give me the same affection if I would gain 100 pounds. How would you respond to that without saying "Yes, your beta husband will love you whatever you do." Or do I just say "yes you are right" because I will keep working on my SMV anyway and she will have to keep up.