[quote=Aragorn]
So, what I'm curious about here is, Japan is the least fattest people in the world, and America is the fattest. Yet, Japan wants to be like us. 
[/quote]

Cultural admiration =/= dietary practice. I'm sure there's things about what the Japanese eat that would repulse you and vice-versa. Keep in mind what they see is usually entertainment like movies and what not. They "want to be American" in the same sense a weeaboo wants to be Japanese. You admire a slice of cultural export without exposure to the reality of that country.