The article says nothing about children lacking the calories required for brain development. It says 23% of black households self-reported "not having enough food in the past week". Which is weird, because when I go looking for objective data that might support the assertion that a significant percentage of the population isn't getting enough calories, I don't find anything. I did find an article that obtained weight data on both whites and blacks nationwide, and broke them down in Underweight, Normal, Overweight, and Obese categories... but the number of underweight individuals was so low that it rolled them into the 'Normal' category, and didn't even report the Underweight category. It's almost like everyone is getting more than enough to eat!

Neither your anecdata on "visible poverty" nor the US Gini index contradict the obvious fact that the USA is, by any serious measure, a rich country.