As I said in the post you're replying to it isn't about calories. It's about nutrients needed for proper brain development.
While conditions are better here in terms of protein other nutrients are still lacking due to poor diet and dark skin and other genetic factors. Vitamin D is the one everyone shouts from the rooftops especially after a study found vitamin D deficient Somali immigrants in both the US and Sweden had exploding autism rates (3-4x risk in vitamin deficient Somalis) likely because vitamin D is important for immune function and metabolic health.
But others are prevalent in black children beyond that. Zinc, iron, vitamin A, DHA, and a few others aren't uncommon.
Notably more blacks are also on welfare and are low income compared to whites and welfare typically means poptarts, frozen pizzas, and other processed junk. None of which are going to support good cognition. From pre-conception (which impacts sperm and egg quality) all the way through pregnancy, infancy, and adolescents blacks are out there eating corn starch and fried chicken and their intelligence continues to suffer for it.
How much could they improve if they just decided to eat healthily for a few generations? The world may never know. They're now locked in a cycle of eating to stunt their brain then being too stupid to do anything to fix it. Corn Starch it is!