That’s because body weight, shape, or size is largely determined by genetics, and as the author pointed out, there is a generational health gap. Additionally, the allostatic load of the stressors of dealing with racism (overt and covert), poverty, inequity and inequality, all contribute to these risk factors you mention.
It’s not “all about diet and healthy eating.” As a dietitian, I appreciate and acknowledge the benefits of healthy eating patterns, but please consider the great privilege that comes along with making those choices. Understanding the atrocities of the past helps us understand why it is not, in fact, about personal choices, but rather the systemic and institutional policies that contribute to these disparities.