There are "systematic differences" in the way they target their ads.
A new study done by the Rudd Center for Food Policy & Obesity at the University of Connecticut, has come up with some unsettling results about the way fast food and junk food is marketed. The study finds, in short, that there are "systematic differences in the types of products targeted to Hispanic and Black consumers." Although the data varies by brand and area, the study's author, Jennifer Harris, says that the results are pretty clear and that these advertising practices are “perpetuating the disparities that we all already see in kids’ health. Kids are very vulnerable to advertising, much more so than adults."
Dr. Christopher Bolling, the chair of the obesity department of the American Association of Pediatrics, channelled Freemon of The Wire as he told the Huffington Post that “the big issue is you follow the money.” The companies "get better return for their buck by advertising heavily in those [low-income] areas, as that’s where people live and are going to have access to those foods" and, partly due to predatory practices like this, in the US income and race are not unrelated categories.
There are bright sides though. The study, which you can read here in its entirety, also found that "total amount that companies spent to advertise restaurants, food, and beverages on all types of TV programming declined" between 2013 and 2017 by 4%.