America is a predominantly white country, despite the fact it is one of the least racist and least homogeneous ones in the world.

>BMI is based primarily on data collected from previous generations of non-Hispanic white populations.

This quote you provided proves my point. If there is an inherent bias in choosing from your own population, that doesn't make the study racist. If the study was Chinese and therefore didn't apply perfectly to Americans, that wouldn't make the focus on Chinese people a sign of racism.

By the way, affinity for your own group is encouraged in every case except for white people. Other groups aren't so stupid as to hate the homogeneity of their homeland. Go live in a more racially uniform country in Asia or Africa and see how much they care about diversity. They want the opposite.