They exist in the US too, but never have seen them in Hong Kong or in Singapore for that matter. Try whole wheat bagles like mentioned above or whole wheat pita?
I can't find any bread here that actually uses unbleached flour or is not made with sugar, let alone bread that is 100% whole wheat. And why is bread sold in only 6 slices? I miss New York terribly...and especially its bagels. The bread in Asia is so unhealthy.